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Non-working Reactionless Drive

Eppur si non muove.
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[Vernon] recently posted a scheme for a "reactionless drive" (link). The idea behind this kind of thing is that the reaction (as in "action and reaction" a la Newton) depends not only on acceleration, but on the rate of increase of acceleration.

Therefore (goes the story), if you can arrange a mass to oscillate to and fro, but accelerating abruptly in one direction and smoothly in the other, it will produce an overall reaction in one direction.

I've discussed this quite a lot on the linked idea, and I would bet my Great Aunt Melony's entire goat-flock that it is moonshine. Let me clarify: I really, really, truly don't believe it would work, because I think the underlying physics is just wishful thinking.

However, one of the problems is that "reactionless drives" seem to involve a huge amount of thrashing around, with big masses moving to and fro (and to again) with varying accelerations. As a consequence, most such machines tend to self-destruct, or thrash about so much as to make fine measurements of net force impossible.

Rather than continue to apply the //bulldozer effect// to Vernon's idea, I would therefore like to propose a much more elegant reactionless drive, which will be easier to build, will not thrash around at all, and which will therefore permit sensitive measurements of net forces (if they existed, which they won't).

Let me iterate and re-iterate, though: this will not work. It really really truly won't work. This idea is merely a way of showing that it won't work, more elegantly. I have enough problems with my genuine mental anomalies, without acquiring a reputation as a nut.

So, to the idea.

The essence of the reactionless drive, as mentioned above, is that masses have to accelerate in different ways in different times. For example, a mass accelerates smoothly in a leftward direction, and then abruptly (with a sudden jerk - a rapid increase in acceleration) in the rightward direction. Overall, the mass just goes back and forth. According to reactionless drive proponents, the reactions to the leftward and rightward accelerations are not the same, resulting a net force in one direction.

So, here's what we do.

First, take a length of pipe and bend it into a circle. To put us all on the same page,this circle is in the horizontal plane (ie, lying flat on a tabletop).

Second, fill the pipe with mercury. It could be almost any other liquid, but mercury is pretty and it is also dense.

Third, use some means to pump the mercury around the pipe continuously (say, clockwise). This could be a regular pump, but it would be neater to use magnetohydrodynamic pumping. In this way, the only moving thing is the mercury.

So far so good? Obviously, pumping the mercury clockwise will tend to make the apparatus want to turn anticlockwise - this is irrelevant. (If it bothers you, put a second, independent loop of pipe on top of the first, with its mercury being pumped anticlockwise; then the torques will all cancel).

Now for the clever bit. Imagine the pipe being marked up like a clock-face, from 1 to 12. We make the section of pipe from 12 to 6 much thinner than the rest. This means that the mercury will move much faster in this half of the circle. It will have to accelerate as it moves from 11:59 to 12:01, and decelerate as it moves from 5:59 to 6:01.

All OK so far?

Now the cleverer bit. At 12 o'clock, where the pipe narrows, we use a step-like constriction. In other words, the pipe narrows from (say) 1 inch to 1/8th of an inch abruptly. This means that the mercury moving rightwards, from 11:59 to 12:01, undergoes a very violent acceleration.

Conversely, at 6 o'clock, where the pipe widens out, we use a gentle taper (from 1/8th of an inch back up to 1 inch). This means that the mercury moving leftwards, from 5:59 to 6:01, undergoes a smooth acceleration.

Of course, we can tinker with the two profiles (the shape of the pipe in going from big-to-small and from small-to-big) in any way we want, to get any acceleration profile we like at each transition.


If reactionless drives work (which they don't, really really really), then this should work nicely as a reactionless drive. The heavy mercury is being accelerated abruptly (with as high a differential in acceleration as you like) when travelling rightwards (at noon on the ring), and smoothly when travelling leftwards (at six on the ring).

These are exactly the parameters which should produce a reactionless force, but there is NO thrashing around - the whole system is as smooth as silk. It is equivalent to an infinite number of small reactionless drives, all operating slightly out of phase with eachother, to give an overall silky smoothness.

Now we can suspend this whole thing from a string, and see if it moves. No thrashing. No wildly spinning motors, no cooling fans, no air currents, just smoothness.

Will it work? NO IT WILL NOT (which is why I am honour-bound to bone this idea). But it will be very easy to see it not working before your very eyes.

(Incidentally, the geometry of the cooling loop on a domestic fridge is not so very different from this, although it doesn't use mercury. Therefore, if you are a reactionless drive believer, you may take encouragement from the tendency of your fridge to slowly creep one way or another, over a period of time.)

MaxwellBuchanan, Mar 10 2011

The less non-thrashy version of this idea. Alternating_20Respo...0Radiate_20Reaction
(won't work either) [MaxwellBuchanan, Mar 10 2011]

Breadcrumbs & Butterbeans http://www.youtube....VyNs27kxolM#t=0m37s
What goes in? What comes out? Has the system changed? [Jinbish, Mar 10 2011]

The Cameron paper http://www.scribd.c...eory-Proven-To-Work
I think, anyway... is this the one? [lurch, Mar 11 2011]

An alternative way to demonstrate reactionless drives [neelandan, Mar 15 2011]

"Digital Physics" http://en.wikipedia...iki/Digital_physics
As mentioned in an annotation about Information as a subject matter of Physics [Vernon, Mar 15 2011]

About Hawking's bet http://www.newscien...ks-the-paradox.html
As mentioned in an annotation. [Vernon, Mar 15 2011]

A "large" version of [neelandan]'s impact drive http://jnaudin.free.fr/images/hbart.jpg
Where "large" is explained in an annotation. [Vernon, Mar 19 2011]

Some videos of bullet impacts at 1million fps. http://www.youtube....watch?v=QfDoQwIAaXg
[Jinbish, Mar 22 2011]

On real data and the refusal to look at it http://www.google.c...IENEKkbyNSIQQzU9FMg
As mentioned in an annotation [Vernon, Mar 28 2011]


       1. It aint really an airtrrrr unless there is them banging weights in tharr.   

       2. This can be replaced by a thin toroid of mercury, the diameter of the narrowest portion, whizzing around real fast while the rest of the mercury stands still.   

       Then there is no acceleration, no gravity waves and no reactionless drive.   


       3. A better way to demonstrate apparent reactionless drive has been posted <link> FARTRRRR-R-R-R   

       This comment was originally just a placeholder, and the text above was added later.
neelandan, Mar 10 2011

       Feel free. But on what grounds?
MaxwellBuchanan, Mar 10 2011

       It is very rare that I get to comment as the first, and it seemed to be too good an opportunity to let go waste.   

       Reactionless drives and overunity electrolysis using sparks all have depended on the limited dynamic range of measuring equipment in order to demonstrate "rectification".   

       The sharp pulse one way drives the system off scale and its influence is under-rated. The more gentler signal the other way gets measured entirely, and is shown to be larger than the effect of the sharp pulse.   

       This, I feel, is the misconception behind the dean drive and the artrr.
neelandan, Mar 10 2011

       I agree completely. That's why I proposed this idea: it avoids all the thrashiness that leads to inadvertent signal rectification. Therefore, it will show that reactionless drives don't work, without the usual excuses.
MaxwellBuchanan, Mar 10 2011

       dude this idea will never work.
WcW, Mar 10 2011

       However if you want to mimic some of the properties of a reactionless drive, you can point your rockets outward and having a spinning vane redirect the thrust backwards. The vane gives more momentum to the rocket exhaust while losing its own momentum as a result.   

       Thus you can increase your velocity without actually tossing more stuff out the back.   

       Which would be pointless except you could spin a heavy vane up to speed, well in advance (as well as during the burn) using a nuclear reactor, while waiting for the time to light the rockets.   

       Which actually is pointless unless you have a material strong enough to be spun fast enough to make it a worthwhile venture. Hybrid rocketry: adding angular momentum to linear.
FlyingToaster, Mar 10 2011

       One could simply scale up the flow until it is turbulent and then vibrate the pipe off the table...Mwahahaha
Ling, Mar 10 2011

       //dude this idea will never work.//   

       Ah, that is the point. Unless you mean that the fact that it will never work will never work as a means of proving that reactionless drives will never work.
MaxwellBuchanan, Mar 10 2011

       Makes sense - this invention is a means of demonstrating that reactionless drives don't work. So, in order for this invention to work, it needs to not work. It's like Zen innovation.
hippo, Mar 10 2011

       Children sitting in pushchairs can move around using a reactionless mechanism, as you've described it. It works because there's a static friction to be overcome before motion can commence.
I wonder whether people remembering doing that is the root of these ideas.
Loris, Mar 10 2011

       //It's like Zen innovation.//   

MaxwellBuchanan, Mar 10 2011

       I agree with [nee], the banging thrashing weights are the whole point of this kind of mechanism - how else are you going to simulate reactionless force though stick-slip?. It's like trying to invent a jackhammer than glides smoothly up and down on silken cords.
pocmloc, Mar 10 2011

       Your writing presents a very clear visual, and I think I see the flaw in the non-proof. This bit right here, //the pipe narrows from (say) 1 inch to 1/8th of an inch abruptly. This means that the mercury moving rightwards, from 11:59 to 12:01, undergoes a very violent acceleration.// allows only a portion of the mercury to violently accelerate while the excess bottlenecks creating backflow and essentially counteracs any effects from acceleration. If the entire volume of the slower moving mercury were to accelelrate you might see a difference.   

       hmmm, If the same experiment used light in the place of mercury and a B.E. condensate as the deccelerant, (is that a word?), would the result stay the same?   

       I thought about that problem. I'm hoping we can get laminar flow here (though this may limit the size of the device.   

       I make microfluidic systems, and I can vouch for the fact that, when going through a step-reduction, the liquid behaves very nicely - the flow-lines are like a set of strings, widely spaced in the wide channel and bunched up in the narrow channel.   

       The beauty of this device is that it can be made small, simple and non-thrashy. That means you should be able to measure even minuscule forces.   

       There are some controls to be done, of course. Magnetic fields need to be nulled out, mainly. If you want to, you can build two of these devices on top of each other, with the mercury flowing in opposite directions but with any predicted "reactionless force" acting the same way. That would let you self-null most non-interesting forces very precisely.   

       My aunt's favourite goat says you'll see no reactionless force whatsoever.
MaxwellBuchanan, Mar 10 2011

       I think you're on the edge of a gedankenexperiment which will show that reactionless drives down't work. Let's start from the premise that a reactionless drive is possible because of a difference in how a force acts on a mass when it acts quickly and when it acts slowly. The mass has no memory so cannot compare the two forces to evaluate which is quicker, instead the effect must really be due to the speed with which the force acts. If this is the case, you should be able to test this with one force, not two. If you can test this with one force, it turns into a standard test of Newton's Third Law of Motion, which must be wrong for this thing to work.
hippo, Mar 10 2011

       [MaxwellBuchanan], the key thing you have overlooked is in my description of the artrr, NOWHERE do I claim it would be reactionless. I merely claim it would be a reaction drive that would LOOK like a reactionless drive. I even described an analogous "drive" that any physicist would accept as valid: an infrared flashlight in outer space. In both cases the reaction/"exhaust" is invisible, infrared radiation with respect to the flashlight, and gravitational radiation with respect to the artrr.   

       The only unknown is whether or not gravitational radiation can actually be generated by the means described at the linked page. There are two simple ways to test for that, and both are desribed at the linked page. There is nothing you (nor [neelandan]) have written that proves gravitational radiation cannot be generated by that means --and therefore there is nothing you (nor [neelandan]) have written that proves an artrr cannot work.
Vernon, Mar 10 2011

       OK then, instead of "reactionless", "its momentum in one direction is balanced by the momentum of the gravity waves"...
hippo, Mar 10 2011

       [hippo] yes, I was wondering if one could gedank one's way to a conclusion, but I didn't make it.   

       [vernon] perhaps I didn't explain my argument clearly enough.   

       This idea does not claim to prove that the "reactionless" (ie, gravity-wave-reacting) drive will not work.   

       I have simply devised an equivalent of your ATRR (and of the Dean Drive, and all the other threshing machines) which is more elegant and would be much much easier to test accurately.   

       I am pretty sure that it won't produce any drive at all, but that's not the point. The point is that, if it does, then so will your thrasher. If it doesn't, then nor will your thrasher.
MaxwellBuchanan, Mar 10 2011

       If your hoop did work as a reactionless drive, what would it do, hanging from the string? Would it spin faster and faster? It seems like the setup would want to make the hoop spin along an axis thru the center of the hoop which as you point out would already occur because the internal pump "will tend to make the apparatus want to turn anticlockwise ". Asymmetry of forces at tight and loose end should just augment this.   

       If you want balance you should have both matched tubes (clockwise and counterclockwise), mount them on a bicycle wheel, and make sure they are balanced such that the thing does not spin. Then introduce the tightness and see if it does spin. I like water for this experiment because it is cheap and aquarium motors move it easily.
bungston, Mar 10 2011

       I just don't get it.   

       Not this idea. I get this one fine. This idea is just some mercury that is being driven round tube. I'm happy with that. Bake it, it'll be nice as a mobile hung from the ceiling.   

       It's the reactionless drive that I don't get. I read [Vernon]'s HB post a while back, and had a brief scout through the links, but not one source could communicate, in terms simple enough for me to understand, what energy is put into the system, what changes in the system, and then what energy comes out. I don't want to hear nonsense about propagation of compression and all that stuff. Just a simple 'what goes in', 'what comes out'...
Jinbish, Mar 10 2011

MaxwellBuchanan, Mar 10 2011

       Indeed, Prof. Yaffle!
Jinbish, Mar 10 2011

       Sp. "Baffle". (or "Baffled")
(or "Waffle")
MaxwellBuchanan, Mar 10 2011

       [bungston], you're quite right, which is why I suggested putting a second hoop with the opposite flow to counterbalance.   

       But there's a prettier way to do this.   

       Make the hoop into a figure-8, with the constrictions at the two extremes. Suspend it from the crossover-point, on its side (so, really, it looks like an infinity sign). Now, the "ordinary" force (ie, mercury going one way tends to make tube spin opposite way) self- cancels (the mercury is flowing "south" at both extremes, hence the reaction is "north" at both extremes, with no net torque).   

       Now, the only assymetric (torquing) force will arise if there is "reactionless force" acting differently at the steep (rapid acceleration) and gradual (slow acceleration) constrictions.   

       I don't know about magnetic fields, but my feeling is that the figure-8 will null these out as well.   

       It's a perfect test of reactionlessness, which will perfectly fail to find any.
MaxwellBuchanan, Mar 10 2011

       You still lost me with the constriction. Even with perfect laminar flow you trade acceleration for volume and there is no change.   

       //...and there is no change//   

Jinbish, Mar 10 2011

       You are trying to prove the negative case here MB. The final refuge of every quack is the failure of others to produce a 'disproof' and thus leave the "seed of great hope". No matter how small we whittle away at the "seed of hope" is cannot be entirely removed. This particular meme has survived without any encouragement for hundreds of years, producing no useful fruit and wasted the efforts of everyone who fell for it. You cannot kill it because it is fed by human optimism.
WcW, Mar 10 2011

       // you trade acceleration for volume//   

       If I understand you correctly, I think you're mistaken (remember, mercury is effectively incompressible, and a constant volume [=mass] of mercury must flow past each point in a closed loop per unit time. )   

       Imagine two ball-bearings being carried in a flow of mercury in a pipe. In one case, the pipe gradually narrows to 1/10th its area - the ball bearing will gradually accelerate to 10x its speed (along with the mercury). In the second case, the pipe narrows step-wise to 1/10th its area - the ballbearing wil accelerate rapidly (not instantaneously, but rapidly) to 10x its speed (along with the mercury).   

       Each "voxel" of mercury will behave like a ball-bearing. Hence, the mercury as a whole accelerates gradually or rapidly in the same way as the ball bearings.   

       ALTERNATIVE ANALYSIS (same result):   

       Imagine the mercury as divided up into a series of discs, one right behind the other, in the wide part of the pipe. One "disc" per second goes past any point in the pipe, whether wide or narrow, but the disc must get longer (and narrower) as it the pipe narrows. If you follow this through (in your head), you'll see that the same mass of mercury gets accelerated gradually in the taper, or very rapidly in the step-down.
MaxwellBuchanan, Mar 10 2011

       So, just as a matter of curiosity, are people boning this because they think it won't work (which is the whole point) or because they think it will?
MaxwellBuchanan, Mar 10 2011

       I boned it just now because I didn't want to feel left out.
bungston, Mar 10 2011

       That seems entirely valid.
MaxwellBuchanan, Mar 10 2011

       //the same mass of mercury gets accelerated gradually in the taper, or very rapidly in the step-down//   


       I've got this horrible feeling that I still don't get it. The mercury is in a closed system (tube). You put energy in to make it flow round the tube. That's it. Isn't it??   

       What am I missing? Where's the paradox that somehow provides energy?
Jinbish, Mar 10 2011

       [Jin], you've got it, and there is no paradox.   

       It's just a tube with mercury being pumped around it. The mercury goes from slow to fast as it enters the narrow part of the tube, and from fast to slow as it returns to the wide part of the tube. There is no reasonable way in which it will do anything exciting.   

       The only complicated thing is that the mercury goes from slow-to-fast very abruptly, and from fast-to-slow gradually.   

       But....according to the ideas behind the "reactionless drive" (with which, in case it's not clear, I don't agree), the abrupt slow-to-fast transition will generate a different force to the gradual fast-to-slow transition. This would lead to a net "reactionless" force. (According to [Vernon], it is only "reactionless" because you can't see the gravity waves which provide the reaction.)   

       It's really only that. The point is that it *won't* do anything magical (I think). Which means that the whole concept behind the "reactionless drive" is wrong.   

       Nothing else.
MaxwellBuchanan, Mar 10 2011

       Excellent. I know you were Devil's advocating, but you just couldn't seem to get to the flim-flam moment where you make the claim of something-for-nothing.   

       Now, I'm off to re-use my last anno on another idea...
Jinbish, Mar 10 2011

       I think you should call it 'circlejerk'.
xaviergisz, Mar 10 2011

       But that would be rood.
MaxwellBuchanan, Mar 10 2011

       /Children sitting in pushchairs can move around using a reactionless mechanism, as you've described it. It works because there's a static friction to be overcome before motion can commence./   

       What about Loris here? Static friction and all. I have just successfully turned myself 90 degrees while sitting in my chair and not having a reaction. I did thrash my arms about some.
bungston, Mar 10 2011

       //I have just successfully turned myself 90 degrees//   

       About which axis?
MaxwellBuchanan, Mar 10 2011

       //So, just as a matter of curiosity, are people boning this because they think it won't work (which is the whole point) or because they think it will?//

Ling, Mar 10 2011

       Vertical axis, and I am sure static friction is the reason I could do it - bringing my arms back slowly was not enough to overcome friction and I stayed still but throwing them forward did overcome, and my chair turned in the opposite direction from the throw of my arm. This seems analogous to your figure 8.
bungston, Mar 10 2011

       [MaxwellBuchanan], my prior post here was written after reading only a couple sentences of the main text. After all, if you don't correctly describe what you are trying to denounce, how can anyone think you know what you are talking about?   

       Having now studied the main text, I see an alternate simple interpretation for the flow of mercury in your tube. Simply pretend the smaller-diameter portion of the tube extends all the way around, inside the larger-diameter portion. The net effect of this description is that only the mercury in that part of the large-diameter tube flows; the rest can be considered relatively stationary. So, no large force occurs at your constriction point, and therefore this design utterly fails to deliver any equivalence to the kinds of forces required to produce gravitational radiation.   

       In closing I'd like to remind you of that paper by Jeffery Cameron (linked on the HB page that describes the artrr), which uses General Relativity to reach the conclusion that an appropriately stressed mass will emit a gravitational wave. Why don't you simply find an error in that math, if you so badly want to prove it can't happen?
Vernon, Mar 11 2011

       //Simply pretend// [marked-for-tagline]
pocmloc, Mar 11 2011

       // only the mercury in that part of the large-diameter tube flows; the rest can be considered relatively stationary.//   

       Yes, except no. Look into how fluids flow through narrowing pipes and you'll understand. Liquid goes faster through narrower bores, assuming that it is pumped a constant (volume per unit time) rate.   

       In any case, although I personally don't believe reactionless drive makes sense, that's not the real point of this idea. The point of this idea was to develop a more elegant "reactionless drive" which accomplishes the same thing (differential acceleration of masses) in a smoother way, to make it easier to test if the thing actually does work or not.   

       I don't believe it will, but that's almost beside the point.   

       One of the ideals of science (which is not often adhered to, but should be) is that you try to find ways to disprove an idea, even if you personally believe it to be correct. For that reason, a more sensitive test which does not bury any possible "reactionless" thrust amidst a load of thrashing and general confusion, is a good thing from either side of the argument.   

       Re. Cameron's paper - the link only points to a page of equations, with no citation. Please, please tell me this was published in a peer-reviewed journal and, if so, let me know where (or even the full title of the paper - I'll search). I'll do my best to comment.
MaxwellBuchanan, Mar 11 2011

       Scratch that, [Vernon].   

       I found Cameron's original "publication". It appears to be by "Jeffery A. Cameron of Transdimensional Technologies, Inc., Huntsville, Alabama."   

       I can find no citation for this paper anywhere, nor can I find it by searching physics journals.   

       Please, help us both out, tell me this isn't just made-up stuff by someone with a vested interest, and tell me where it was first published.
MaxwellBuchanan, Mar 11 2011

       I found something on Scribd that might be the paper [Vernon] is talking about.   

       That is an absolute hoot. I mean, I am not a mathematician to that level on any day of the week (unfortunately, my first serious girlfriend and my differential equations class temporally coincided, resulting in mutual destructive interference) but here's what I'm getting from that paper.   

       "Let's take a quartz rod and make a gravitational laser. We have no clue about how to reflect a gravitational wave, so we can safely assume that we can do all the necessary amplification in a single pass. We can't align the nudges at light-speed, so we will just make the claim that gravitational waves propagate acoustically through - and near - quartz, rather than at light-speed. And since we have no clue about the nature of the gravitational wave propagation in quartz, we can assume that it functions as a totally flawless wave-guide. From the above, the following is obvious..."   

       The math, though it might be quite correct in isolation, appears to be a non-sequitur to the subject matter.
lurch, Mar 11 2011

       [MaxwellBuchanan], if you have a system in which you KNOW all the fluid passes through the narrow point, then, yes, all the fluid must accelerate at that narrowing, I'm disputing that this is necessarily the case in your mercury-filled tube. The viscosity of the fluid is a factor here, which for mercury is pretty low (and for Helium II is Zero; I would expect Helium II to behave almost exactly as I described in my prior anno).   

       Another thing, which I didn't point out before, has to do with the way an applied force affects the entirety of a mass. I don't see how this can happen to the mercury at any significant distance from the bottleneck, because it is fluid, not solid. That "Critical Action Time" that Davis & Stine talked about, with respect to the time it takes a force to affect a whole mass, is called that because it is, indeed, Critical to the process that generates gravitational waves. So, if you don't have that CAT, then you don't get results that look like reactionless motion.   

       As for Jeffery Cameron's paper, I first heard about it as a news blurb at slashdot.org, when it was described as being presented at a meeting (in 2001, I think) of the AIAA (American Institute of Aeronautics and Astronautics). I downloaded a copy at that time from the Transdimensional Technologies (TDT below) website, and have not paid any attention to whatever papers afterward might have cited it. I'm fairly sure, though, that TDT was able to get a grant to do some experiments, on the basis of that paper. I do know that at one point the archive.org link presented a message saying that per robots.txt at the TDT website, the paper had been requested to not be accessible. That's why I created the much smaller .gif image of the first part of the paper, and linked it. Sometime later the TDT website went down and stayed down (along with its robots.txt file), and then the archive.org link began to work...   

       If the experiments failed, that does not mean the math was bad. It could simply mean the interpretation of the math, with respect to designing the experiments, was faulty. Not unlike my 2nd artrr experiment, see? The most important thing, to me, is that the math supports the idea that a stressed mass can emit a gravitational wave (one of 5 different starting points in Physics that can reach that conclusion).
Vernon, Mar 11 2011

       //tell me this isn't just made-up stuff by someone with a vested interest// Why am I thinking Moses and some stone tablets at this point?   

       To my shame, I did try something similar, for a very different reason, and with air, in a toroid-like duct with an impeller and a piece of a wing section facing towards the impeller. That way you get differential acceleration, as the air/mercury that went over the wing tries to play catch up, with the stuff that went under the wing. Didn't work, but a way to generate low pressures in a toroid, if anyone actually ever wanted to do that.
not_morrison_rm, Mar 11 2011

       /Imagine two ball-bearings being carried in a flow of mercury in a pipe. In one case, the pipe gradually narrows to 1/10th its area - the ball bearing will gradually accelerate to 10x its speed (along with the mercury). In the second case, the pipe narrows step-wise to 1/10th its area - the ballbearing wil accelerate rapidly (not instantaneously, but rapidly) to 10x its speed (along with the mercury).//   

       That is true, but the distance between the balls will then increase so that the distance travelled at the new speed will be the same in ratio as the larger volume/lower speed mercury. If you tether the two balls together then the mercury must be shoved out of the way.   

       Be it balls or disks or bottle brushes and even given un-compressability of the fluid, perfect laminer flow and zero viscosity.
Still same/same.

       ...and is my question of using photons in place of ball bearings and and slowing light without a constriction of volume a non-question?   

       On fluid flow: put liquid from a wide pipe to a narrow pipe and it speeds up. I can't help it, it just does. I've coincidentally spent most of today watching it do that as part of my day job. If you'd prefer it not to, it's fine.   

       On the Cameron "paper" - fine. It's far too far ahead of it's time to get published in a peer review, and it's far too important to need to be right.   

       Sometimes, the word "Wha'ever" springs to mind.
MaxwellBuchanan, Mar 11 2011

       [MaxwellBuchanan], I can play devil's advocate, too. What about average motions of molecules in the larger-diameter pipe? If some go fast and some are stationary, the average is the same as if all go slow. Heh!   

       Anyway, you haven't answered my point about how this sudden acceleration at the bottleneck affects the WHOLE mass of mercury. So far as I can see, it only affects the mercury being accelerated --no significant Critical Action Time, therefore, and thus no associated emission of gravitational radiation, and thus no motion that might appear to be "reactionless".
Vernon, Mar 12 2011

       I get it [MB], I just think it's apples to apples.   

       //How this sudden acceleration at the bottleneck affects the WHOLE mass of mercury.//   

       OK, I have a litre of mercury (as a slug in a continuous flow) heading towards this bottleneck at 1m/s. The pipe gets narrower by a factor of 10 in area. That litre of mercury will be going at 10m/s when it's in the narrow part of the pipe. The only way it can not is if some of the mercury hops out into another dimension, or if you turn off the pump, or if you find a way to compress mercury by a factor of ten. There's another litre of mercury right behind it, so it's got nowhere to go.   

       I don't know how to explain this any differently, because I don't understand what you're not seeing. I might point out that pretty much all I'm doing experimentally at the moment is pumping liquids through microfluidic channels, where the velocity is directly calculable (and observable) from the volumetric flow divided by the cross sectional area.   

       Maybe we're talking at cross purposes here. Are you thinking of something like a fan moving air, or wind blowing through a gulley? That's the wrong analogy, since the mercury is pumped at a constant volumetric rate (litres per minute or whatever) and is incompressible.
MaxwellBuchanan, Mar 12 2011

       [MaxwellBuchanan], I'm going to quote something I wrote Feb 12 at the other Idea page:
[xaviergisz], a well-designed and well-built gadget that fails to pass the pendulum test should be able to lay this matter to rest. By "well designed" I mean that anyone thinking it might work would agree that the design incorporates all the apprpriate key elements of the hypothesis-of-operation.

       For example, my 2nd experiment failed to pass the pendulum test, but I was not convinced that its design was good enough....
[quote ends]

       I do not see how your mercury experiment incorporates all the appropriate key elements of the hypothesis of operation. In this vein I can mention that about 1987 there was published in a local newspaper an article about a local fellow who had constructed a mechanical gadget that was claimed to move reactionlessly --at least when mounted on a wheeled table the whole thing was able to move when the gadget was turned on.   

       I went to see the guy, and showed him the articles I had collected regarding the Dean Drive and the hypothesis of operation, and talked him into doing the Pendulum Test. I also mentioned that I did not see how his device incorporated the key elements of the hypothesis --its primary motions were purely and smoothly circular, but it had some offset masses attached that, while they also moved circularly, the center-of-mass of their circular motion was not aligned with the drive axles.
o--0 . a . . . o--0
In this diagram the letter "a" represents the major axle, and each small "o" represents an attachment point on a circular disk that rotates around that axle. Ignore the dots; the little horizontal lines are attachment-rods to the attached masses represented by each "0". Each attachment-point is also a minor axle; there was some gearing behind-the-scenes that ensured the orientation of the attached masses remained pointed in the same direction while multiple minor axles and their attached weights were rotated about the major axle.

       Anyway, the device failed to pass the Pendulum Test.   

       So far as I can see, there MUST be masses being subjected to "jerks" somewhere within a purported reactionless device, for it to have a chance of working. And your mercury experiment only jerks small amounts of mass being passed through your bottleneck, not largish masses that have a significant Critical Action Time, in responding to applied jerks.
Vernon, Mar 12 2011

       A reasonable argument. However, the masses in the mercury loop can be as heavy as you want, within reason (for example, you might have a few litres of mercury in the ring - a few 10s of kilos). Also, the "jerk" is happening continuously - you can think of it as consisting of a very large number of very small masses, each being jerked consecutively. Whether this mass being jerked to this extent is "predicted" to produce a significant effect, I don't know. It does have the advantage of enabling you to measure even a very very small effect, free of thrashing.   

       Is the system calculable? Does anyone claim to have a sufficiently sound theoretical framework to calculate the predicted reactionless drive, even for a "thrashing" system?   

       There should be a simple equation for predicting the "reactionless force" arising from one simple acceleration/deceleration of a given mass, and perhaps the speed of sound in the material. In other words:   

       Fr = f(M, a1, a'1, a2, a'2, t1, t2, S)   

       where Fr is the net "reactionless force" of one "thrash", M is the mass, a1 and a2 are the initial accelerations in each direction respectively, a'1 and a'2 are the derivatives of these accelerations respectively, and S is the speed of sound in the material.   

       If you or anyone else can show me an equation - written in conventional notation and not any whacko symbols* - that fits the bill, then we're on to a winner. It means that the predicted reactionless forces can be calculated for any system involving differential accelerations, including the mercury loop. Then we can tell if, according to the theory, there is any measurable predicted force to measure.   

       *(For example, saying that Fr = f(M, a1, a2, Z, S) where Z is some weird thing that relates to a1, a'2 and S is whacko. Since the elementary system should depend only on masses, accelerations, derivatives of acceleration and the speed of sound in the material, you don't need any fudge factors).   

       If no such equation exists, it's pretty clear that even the guys who tout this stuff don't understand much.
MaxwellBuchanan, Mar 12 2011

       [MaxwellBuchanan], I think you aren't "getting" what I'm talking about. In the battering-ram thought-experiment, when one end of it experiences a large force, there is a propagation of that force through the length of the battering ram. I see no equivalent propagation of force in your mercury-filled plumbing; I only see force being applied to the small amount of mercury at the bottleneck, and not to all the mercury in the rest of the plumbing.   

       Regarding equations, perhaps some of Dr. Davis' equations can be manipulated to get what you are looking for. In his ANALOG article, Equations 10 through 14 (especially 11) describe a distance X that a mass moves in response to a jerk-force. You can easily compute X from ordinary Newtonian equations that don't include jerk. Davis says that X will be less when his equations are used. So, the difference would be related (though not as cleanly as you are asking for) to apparent reactionlessness --perhaps "disappearing action" would be a better description.   

       Think how that applies to the battering-ram thought-experiment. If the large force yields a smaller overall motion in Direction A, than the multiple distributed small forces are able to make it move in Direction B (thanks to less jerk), then it logically follows that when the two are alternately applied for a significant time, there should be some overall motion in Direction B.
Vernon, Mar 13 2011

       //Davis says that X will be less when his equations are used. So, the difference would be related (though not as cleanly as you are asking for) to apparent reactionlessness --perhaps "disappearing action" would be a better description.//   

       Eee-awww. We'll hand that over to the other team...
MaxwellBuchanan, Mar 13 2011

       I think part of the problem with the arguments here is too much focus on the analogies and stuff.
If a difference of acceleration causes a 'reactionless motion', then ANY difference (assuming measureability and beating friction) should gain a result, independent of how the difference is generated (be it flowing liquids or bashing battering rams). That's the point of laws of physics - the best ones apply everywhere.
In particular, no laws I know of have a step-change at some point; everything is smooth (speed-of-light anomaly notwithstanding; but the equation is consistent).
neutrinos_shadow, Mar 13 2011

       Absolutely, and elegantly put.   

       That's one of the reasons I was keen to suggest something like this. It may not generate *much* reactionless drive (in fact, of course, it will generate no reactionless drive at all); but because it can be made to run as smoothly as an oiled stoat on ice, *any* reactionless drive would be measurable.   

       (Item 5c on my own version of the Whacko Index reads: "c. The claimed effect is not seen in isolation, but only as a small “anomaly” superimposed on a much larger, conventional effect. " - in [Vernon's] machine, the "conventional effect" is the huge amount of thrashing.)
MaxwellBuchanan, Mar 13 2011

       //only as a small “anomaly” superimposed on a much larger, conventional effect// Like the precession of the perihelion of Mercury.
mouseposture, Mar 13 2011

       Or Tranmere Rovers winning at home.
8th of 7, Mar 13 2011

       [neutrinos shadow], Quantum Mechanics is chock-full of step-changes. And it just so happens that when Newtonian Mechanics is tweaked per Dr. Davis' hypothesis regarding Force and jerk, ...   

       "...in late 1961, I sat astounded and watched Professor Korff derive Planck’s Constant and the quantum condition from Newtonian mechanics using the hypothesis of Davis..." --from Stine's ANALOG article (linked on the artrr page).
Vernon, Mar 14 2011

       [Vernon]; sorry, I accept that. It's been a while since I did any deep physics. (Note to self: learn more stuff about quantum effects...)
On the other hand, the reactionless drive is a macroscale effect (in theory), and probably doesn't involve any quantum weirdness.
neutrinos_shadow, Mar 14 2011

       //macroscale effect (in theory), probably doesn't involve any quantum weirdness.// All macro effects involve "quantum wierdness", it is just, on average (read all of the time), a lot of the wierdness cancels out entirely. Mainly because the set of weirdness is vastly smaller than the set of non-wierdness.   

       on the original tapioca; This lub-dub physics, as I call it, won't amount to much. It generally works only in a gravity well ([bigsleep]'s link) because you are operating your uneven acceleration against a frame of reference. Its a fucking skateboard. Now unless you presume that our entire universe is, itself, a gravity well in relation to something else, well then you may have a point, but you are going to have to do something on a bigger scale than hammering a battering ram in a timed sequence.   

       Now, there are much more interesting proposals of getting "acceleration" without reaction mass that don't rely on: "If I subtract 7 from this side faster and in smaller increments than I subtract the 7 on the other side of the equation I can go somewhere". Will try find link...
4whom, Mar 14 2011

       //Quantum Mechanics is chock-full of step-changes.//   

       I'm probably revealing gigantic gaps in my ignorance here, but what are they? I thought the whole point was that very tiny things are very quantummy, and very big things are hardly quantummy at all, whilst middle-sized things are middling quantummy?
MaxwellBuchanan, Mar 14 2011

       [MaxwellBuchanan], I was replying to a general statement that "no laws that I know of have a step-change at some point". I am quite aware that macroscopic events tend to be more smooth than stepped, although certain types of large-scale "steps" are widely known (earthquakes, for example, which are part of the category of "catastrophic failure of materials subjected to increasing stress").   

       In the case of the stuff that Dr. Davis talks about, I suspect that we are dealing with an exponential curve. In more detail, I picture low-to-middling impacts being associated with unnoticeable quantities of momentum getting radiated, while larger --and of course more destructive to sensitive measurement devices-- impacts would radiate momentum in increasingly-greater quantity --the equations DO have a third-derivative (or third power) term in them, after all.   

       And regarding Professor Korff deriving Planck's Constant, I think that's just plain cool. It implies that Dr. Davis' work actually is consistent with the rest of Physics, and is neither violating nor rewriting it. It COULD mean that this variant of Newtonian Mechanics is the right math to use when studying the middle ground where the effects of QM start to get buried under their own statistics, and where macroscopic behavior begins to emerge.
Vernon, Mar 14 2011

       [vernon] sorry - what I meant by my question was "what are the step-changes involved in quantum mechanics?"   

       You said in a previous anno that //Quantum Mechanics is chock-full of step-changes.//.   

       So, did you mean
(a) that the *laws* governing quantum mechanics have step-changes in them with respect to size, energy or something? or
(b) that quantum behaviour is by nature "steppy" (eg, photon-or- no-photon)?

       If (a), then I'm asking out of curiousity, because I've missed something interesting in quantum mechanics (which I understand only at a shallow level).   

       If (b), then yes, of course, but the underlying *laws* are continuous, which is the point [neutrinos shadow] was making.
MaxwellBuchanan, Mar 15 2011

       [MaxwellBuchanan], quantum mechanics was originally devised to explain how photons of certain distinct energy levels were related to particular excited atoms emitting those photons.   

       The model accepted today is that the atomic nucleus has surrounding it layers of "shells", "subshells", and "orbitals" containing electrons, and if an electron moves from any layer to any other layer (definitely qualifying as a "step"), then a particular amount of energy must be associated (either absorbed or emitted) with that movement.   

       A point of semantics is now relevant. If two atoms of Oxygen-16 are studied, they are considered to be identical enough that the word "different" is not normally used to distinguish them. An atom of Carbon-12, of course, qualifies as "different" from one of Oxygen-16,   

       For different atoms, which contain different numbers of protons in their nuclei, the layers of electrons are at different distances and are associated with different degrees of electrostatic attraction, between electrons in those layers, and the nuclear protons. Even though similar layers have the same names in different atoms, this difference of electrostatic attraction means that if two electrons make jumps between the same-named two innermost layers of two different atoms, they will still be associated with photons of different energies.   

       Note that if you have a completely-ionized atom, and allow one electron to carefully orbit it in what would normally be its outermost layer, that electron could in theory perform a series of steps, falling one layer at a time and emitting a photon at each step, working its way to the innermost layer. (More commonly though, the electron will make one large quantum leap directly to the bottom layer, and just one highly energetic photon will be emitted.)   

       I should mention that the underlying Rule controlling the locations of the layers depends on the "wave-particle duality" of the electron. I assume you know that an electron is able to sometimes exhibit some wave-like behavior and has a particular wavelength? Well, the innermost orbit of an atom is EXACTLY ONE electron-wavelength in circumference. The next-larger orbit is exactly two electron-wavelengths in circumference; the one after that is exactly three electron-wavelengths, and so on. No continuum here, not at all!   

       (I now need to mention that the amount of electrostatic attraction between a nucleus and an electron can affect the electron's wavelength, meaning that a nucleus with lots of protons can shrink somewhat the diameters of the orbits taken by its electrons. Note the amount of this shrinkage also occurs in steps, because the quantity of electric charge in various different nuclei only changes in steps --by whole numbers of protons, that is, with each one containing the same fixed quantity of electric charge.)
Vernon, Mar 15 2011

       [vernon] when I referred to "gigantic gaps in my ignorance", I didn't mean _that_ gigantic!   

       Again, you have described the ___phenomena___ of quantization which are, more or less by definition, ah, quantized.   

       The point I was making (which, in turn, was a reiteration of the point made by [neutrino's shadow] is that the ___laws___ of quantum mechanics are not quantal. There is no step-change in the ___laws___. A photon is very very quantummy. An electron is very quantummy. A molecule of DNA is slightly quantummy. An oyster is a very tiny bit quantummy.   

       The ___laws___ underpinning quantum mechanics, like all physical laws, show no step-change with regard to size, velocity, charge, mass or sexuality.
MaxwellBuchanan, Mar 15 2011

       [MaxwellBuchanan], the laws you seem to be talking about are useless if they don't describe the real world. So, to describe the real world, it is necessary to (usually) put whole numbers (not irrational fractions) into the equations. The application of those laws is therefore full of step-changes.   

       You might be willing to admit that the underlying laws are not really complete, because we don't know why various quantized things (mass of electron, electric charge of proton, etc.) have the particular values we've measured. There are plenty of hypotheses being devised, of course, to try to generate those values from "first principles".   

       One of those first principles has only been considered as part of Physics for a few decades, and could be called a "Law of Conservation of Information".   

       To me, one of the most interesting efforts was developed by a Frederick W. Kantor, and is called "Information Mechanics". If you can agree that information is binary and quantized, then you might have to accept the possibility that anything derived from manipulating information will have a "step" aspect to it. I'll add a link.   

       Then there is that matter of a relatively famous bet that Steven Hawking made, and later decided he was wrong. He had indicated that a black hole would be able to destroy the Information associated with anything that fell into it.   

       Remember that he already had shown how a black hole could "evaporate" given enough eons of not-swallowing anything. If Information was Conserved, how could it get back out of the black hole during the evaporation process? If I recall right, Hawking's answer depends on the idea that Space and Time are actually quantized, and are not continuua. I'll add another link.
Vernon, Mar 15 2011

       //...laws you seem to be talking about are useless if they don't describe the real world.//   

       If you understood that quanta may be arbitrarily and infinitely small, you'd realize that the laws *have* to be free of step-changes to accurately describe the real world.
lurch, Mar 15 2011

       [lurch], by definition of "quantum", it may be arbitrarily small, but it may not be infinitely small. Infinite smallness leads to descriptions of continuua, such as Space and Time have long been presumed to consist of. The existence of quanta means that something is "grainy" instead of continuous. Ordinary physical matter, for example, is grainy because it is made of quanta (individual grains) known as "molecules" or "atoms" (depends on the type of ordinary matter).
Vernon, Mar 16 2011

       [lurch], the upper limit for a photon is related to the fact that the more energy it has, the smaller it is and the more gravitational field it will have (in General Relativity, gravitation is related to mass AND energy, not just mass alone). There's a point where if it has too much energy, it won't be a photon any more; it will become a smallish black hole.
Vernon, Mar 16 2011

       [Vernon] - sorry, I had deleted my anno - but what I asked was not the upper limit on *energy*, but the upper limit on *wavelength*. You'll notice that as wavelengths get very long, energy is very small.
lurch, Mar 16 2011

       //The application of those laws is therefore full of step- changes.//   

       Yes yes yes yes. Yes. Indeed yes. However, I may have neglected to mention (checks - ah, apparently I did not neglect) to point out that I am talking not about the applications of the laws, but about the laws themselves, which are continuous with respect to all other continuous variables. It's a fundamentally different point, and I apologize for not being able to find a way to make it clearer.
MaxwellBuchanan, Mar 16 2011

       [lurch], well, with the anno gone, I can't be sure whether it was actually in it, but I thought you used the word "frequency", not wavelength. I do recall wondering at the time why you seemed to have switched from minima to maxima.   

       As for the longest wavelength, it might be arguable that the diameter of the Universe is an upper limit.   

       [MaxwellBuchanan], I still don't see your point. The laws only describe Reality when integers or ordinary fractions are fed into them. Why does it matter that the math could allow, say, irrational numbers to be used, when the results would be just as irrational?
Vernon, Mar 16 2011

       [vernon] apologies - I'm probably not explaining very well.   

       OK, put quantum mechanics on hold for a moment and take, say, something simple like charge. The force between two charges varies smoothly depending on the charges and on the distance between them, and the same equations apply whether the charges are a meter or a micron apart. It's irrelevant that charge only comes in electron-sized units - if you had a half-an-electron charge, the equations would work just the same.   

       Or take relativistic mass - the mass of an object increases smoothly (not linearly, but _smoothly_) with its velocity; again, you can use the same equation to calculate the mass increase of an object whether it's travelling at walking-pace or close to the speed of light.   

       The point is that the *law* doesn't have step-changes in it. It's not as if you need one law to calculate the force when the charges are a metre apart, but a different law to calculate the force when the charges are 1.1 metres apart. Likewise, you don't need one law to calculate relativistic mass increases below 1000mph, and a different law to calculate them above 1000mph.   

       Why is this relevant here? For two reasons. First, it means that any theory of "reactionless drive" should apply to any situation where masses are "jerked", even if the masses and the jerk are small. It should be able to calculate the "reactionless drive" effect in any such situation, and my guess (it is only a guess) is that such a calculation would predict "reactionless drive" in many everyday situations where it clearly does not occur. (As an example, you suggested that structural failures in ejector seats were due to this kind of phenomenon; an effect this large would have been measured a million times in a thousand different everyday situations before now, if it existed.)   

       The second reason it's relevant is that it allows you to predict the "reactionless drive" from a set-up such as the one I suggest here. In other words, my proposed machine may not be expected to show as much "reactionless drive" as yours, but it cannot show none at all, unless the laws governing this behaviour simply "switch off" below some threshold mass or acceleration.   


       Coming back to the ejector seat, by the way. It's "anomalous behaviour" was taken as support for some "weird" effect of "jerk". I put it to you again - if this were the case, then we are talking about a relatively HUGE "weird" effect occuring at large, but not enormous, accelerations. This would long ago have become well- known, if it were real.   

       A car's pistons probably undergo similar or greater "jerk" compared to the ejector seat. An artillery shell (which may include very sophisticated timers, pressure sensors and all kinds of other stuff, and has been very very well studied) undoubtedly undergoes much greater "jerk" when it is fired.   

       So, the fact that extremes of this "weird" phenomenon are not clearly seen in these other commonplace situations tells me that the "weird" behaviour of the ejector seat cannot possibly be "weird" in the way you think it was.   


       Can I ask you a question, which you don't need to answer if you prefer not to? When you posted this idea, by what percentage did you believe there was something real in it? And what's the percentage now, after all this toing and froing?   


       Finally, one last question. These guys claim to have equations to predict the "weird" behaviour of complex machines, based on this assumed phenomenon.   

       Well, to derive those equations, they must have equations describing this phenomenon in its simpler form (you can't calculate heat-flow in a car engine, unless you have equations describing the heat-flow through a simple cube of metal).   

       Therefore, it must be trivial to answer the following question: If I take a 1kg mass, and move it back and forth repeatedly over a 1m distance with an acceleration of 100g when going left, but only 1g when going right, what will be the magnitude and direction of the net reactionless force?   

       If there isn't an answer to this equation, then these guys are bullshitting prodigiously and are frauds.
MaxwellBuchanan, Mar 16 2011

       [MaxwellBuchanan], I need to repeat the start of an earlier reply: "I was replying to a general statement that "no laws that I know of have a step-change at some point"."   

       So I mentioned QM. If you now want to talk about other laws, then you are explicitly ignoring the point I originally made (and which [neutrinos shadow] accepted gracefully), that QM is an example of some laws that do have lots of step-changes.   

       There is one thing that I need to clarify about QM, though, and that is the fact that while various things come in "packets" or quanta, it is not certain that there is a minimum fixed interval between packet-sizes. It is possible, though, and would be likely if the things known as "Planck length" and "Planck time" were actually associated with Space and Time (meaning that they are quantized and are not continua).   

       With quantized space-time, the examples of smoothness that you described would actually have to be stepped at the ultra-small scale. NO exceptions! And remember, if a Law of Conservation of Information is actually valid, then per Steven Hawking's resolution of the bet he made, space-time likely has to be quantized (it would be a required consequence of the Conservation Law).   

       Next, I've stated before that I think there is a curve involved with respect to how masses respond to various intensities of jerk. No significant "step". And I know you know there are other examples of such curves in Physics (e.g., the relativistic mass-increase with velocity doesn't become significant until speeds that are several percent of light-speed are involved).   

       So that is a simple reason why ordinary jerks don't need to have super-obvious effects, while extreme jerks can (as described by Stine). It also means that ordinary Newtonian Mechanics remains quite useful in ordinary situations, exactly as it remains quite useful with respect to ordinary velocities and Relativity.   

       So, if you don't expect to measure a relativistic mass increase for your car when it drives down the road at highway speeds, why should you expect to measure significant effects of the small jerk in your mercury device? (Not to rmention a point previously made, about the apparent need for a jerk to propagate through a mass, which doesn't seem to be a factor at all, in your device.)   

       The examples of more-extreme common jerks are, so far as I know, all of them examples where engineers grumbled about "finagle factors" until they constructed something that would hold together under the forces involved. Trial and error! Not designs totally dependent on Theory being correct. So, it might be interesting to see what a physicist might say about the degree to which a gasoline engine piston is "overengineered" with respect to what Standard Theory says should be adequate.   

       I'm not aware of any such comparisons ever having been made. Meanwhile, Stine's problem happened because they were dealing with aircraft, where weight considerations have always been an important factor. They needed the lightest-weight parts that were strong enough, and so used Standard Theory to design them. And the parts came up wanting....   

       Regarding the Question you delicately asked, I had to laugh. I quote you (so you can laugh, too): "When you posted this idea" ... this here page is Your Idea. :)   

       The Answer is that since Stine's article was published in 1976, I've always thought Dr. Davis' hypothesis made enough sense that it deserved to be tested. And so I wasted money 4 times, as described elsewhere, on tests that failed, but failed in ways that were not conclusive. So I'm willing to try again, ...when I'm ready.   

       To answer your other question, "those guys" are mostly dead and unavailable to do the calculations you requested (and while I'm excellent at algebra, my calculus skills are not worth talking about). Their research started 50 years ago, and the team was (by corporate fiat) broken up in 1964 and went separate ways. The likeliest survivor is E.L. Victory, who was young at the time (and what the "E" stands for was, so far as I know, never published).
Vernon, Mar 16 2011

       //my calculus skills//   

       I'm sure you know your way around an integral or two, [Vernon] - but that's not really too important here. Unless we're doing proofs, it is not likely that the mathematics will be the source of any controversy - and it certainly doesn't seem to be the case in this situation. The calculus is a distraction.
When James Clerk Maxwell amended Ampere's law it wasn't because Ampere had got his dy/dx in a twist, it was because the law didn't fit certain well known circumstances (did not take bound charge into account).

       The issue at hand with regards to a reactionless interaction is to do with the lack of observational data. The thought experiment discussed in the ARTRR idea doesn't stand up to a real interrogation (you can account for everything with Newtonian mechanics). That leaves us with anecdotal evidence of discussions and experiments done circa 60s/70s which haven't been adequately published. Nevermind the NASA pilot or whatever - if there was a real phenomenon involved then it would be reproduceable and investigated by many other sources.   

       As [MB] touches upon, scientific problems / shortcomings can be easily publicised and will raise eyebrows and make people think "how does that happen?!". With something as fundamentally simple to measure as Newton's Second Law you would think that a refutation or amendment at the the non-relatavistic level would have cropped up by now. Principia Mathematica has been around since 1687, for goodness sake.   

       Of course, our knowledge of science is imperfect and up for challenge - but we need a body of evidence to mount this challenge. Is there really a descrepancy in displacement? If so then we can say "Oooh, it's gravity wave emission due to a temporary increase in energy/mass of the object that bends space-time"... If there is no evidence of discrepancy then we have no ball game.   

       Please don't chase this [Vernon], I'm certainly no mechanical engineer -nor am I a physicist {splitters!!}, but searching for this reactionless transaction by constructing shaky machines reminds me of the search for turning lead into gold by boiling it with whatever concotion the alchemist can think of...   

       <slokes off to make his own reactionless drive... mwuh-hah-hah!>
Jinbish, Mar 16 2011

       There seems to be some pretty huge order-of-magnitude differences...   

       Dean - claimed 45% phase variance   

       Davis/Stine - claimed 3%   

       Einstein - difference between mass & momentum allowed to occur after the 11th decimal place in whatever equation set that was.
FlyingToaster, Mar 16 2011

       [Jinbish], Stine's article describes a number of things that perhaps "defy" Standard Newtonian Mechanics. And I get the idea that SNM gets tweaked in different ways to describe each of those cases. Meanwhile, Davis' more-generic modification to SNM seems to yield a consistent way of describing those cases.   

       [FlyingToaster], you must have noticed that Stine himself expressed some puzzlement about Dean's claims regarding a 45-degree phase angle. And Stine offered a couple of possible explanations. Personally, I wonder if Dean ever actually observed the thing he claimed; it is not impossible that that is what he needed to THINK was happening, in order to be comfortable in his own thoughts, regarding how his Drive worked.   

       In other words, Dean didn't create his Drive in an idea-vacuum. He had some notion regarding how he thought it should work, and then he built something to try to match that concept. If the result actually worked, then both Dean and Davis are agreed that a phase angle is an important factor in why it worked.   

       I note that the way Stine tells the story, there is a possibility that Davis may have independently discovered the role of a phase angle (his artcle was published in 1962, while Dean published a letter describing "phasing behavior" in 1963). I can't say for sure that Davis was independent, since he did personally visit Dean and discuss the Drive and witness a demonstration. Dean might have mentioned it during the discussion.   

       And, of course, it is important to remember that as far as Standard Newtonian Mechanics is concerned, ANY non-zero phase angle is always supposed to be impossible to achieve.
Vernon, Mar 16 2011

       //a number of things that perhaps//
//I get the idea that SNM gets tweaked in different ways//

       Sorry, [Vernon], it's all a bit too hand-wavy for me. "He said this", "they reckoned this", "they were astonished - but it seemed real". There just isn't the real evidence, nor clarity of analysis. I mean, I'd *love* to be able to say that there is a chink in the current science - but it just isn't there (at least not in this area).   

       Best of luck with your invention & testing - or at least your continued fortitude in defending the indefensible.
Jinbish, Mar 17 2011

       From what I can understand of the idea and succeeding annotations, it appears that there is some sort of issue with a drive? If so MB, then I know some people who would be prepared to tarmac it for you at a very reasonable price.
DrBob, Mar 17 2011

       [Jinbish], I'm not one of those True Believer types to blindly accept stuff on faith. But I don't mind saying whether or not something, to me, makes logical sense. So, with respect to various claims made, all I can say, FIRST, is that such-and-such are the claims made, and then I can say whether or not they make sense to me.   

       The detractors seem to be blindly taking on faith that there are no more holes in Newtonian Mechanics, even though History proved conclusively that it had at least two (which were filled by developing Quantum Mechanics and Relativity). I can't agree, blindly, that there are no others.
Vernon, Mar 17 2011

       That's fair enough, [V]. I'm just not convinced on this one. The analogy with Ampere's law is interesting because Maxwell added a term that made the equation fit more *known* cases. It just seems that F=ma is all that is required for the scale that we've been discussing and that F=ma + d2a/dt2 or something is just not needed (let alone any explanations involving gravity waves...).
Jinbish, Mar 17 2011

       Ok - let me rephrase that then:   

       F=ma, coupled with the effects of compression, friction, heat, and relativistic effects seems to be adequate to describe what is happening.   

       I'm not saying that there isn't another effect at play - what I am mean to say is that the evidence presented through this idea and the ATRRTRTR idea are as solid as a fart in a breeze.
Jinbish, Mar 17 2011

       [vernon] - sorry, I've been off-duty most of the day.   

       Regarding "QM is an example of some laws that do have lots of step-changes." - I cited the examples of relativistic mass and electrostatics to explain what I meant by step- changes in the laws, and why this was important, but I forgot to come back to QM, sorry. So, coming back. The _laws_ in QM _don't_ have step changes, they truly really honestly don't. The same laws apply equally (and smoothly) to electrons and to elephants. I can (at least, one could) calculate the behaviour of electrons in a two- slit experiment; I can calculate the behaviour of protons, buckyballs or bacteria in the same way. There's _no_ step change in the laws. There's nothing that says "if the mass is less than X, it diffracts this way; if it's even a little more than X, it does something unrelated".   

       To say that quantization means there's step-changes in the laws of QM is like saying that gravity is quantized because only whole numbers of apples fall off trees.   


       Regarding jerks and "finagling engineers" - sure. But, are you seriously trying to tell me that a "new" type of force, which is roughly comparable in magnitude to the "usual" forces (as it must be make engineered aerospace structures fail "inexplicably") has gone un-noticed, un- analysed, un-investigated and un-accounted for over the last few decades? Come off it, you must realize that that is a ridiculous statement.   


       Finally, regarding the equation. Point taken, we can't ask the dead about this one. However, NOBODY has presented the most basic, simple, elementary equation governing this behaviour. All I have seen are idiosyncratically- symbolized* equations which claim to describe the behaviour of highly derived machines.   

       It's a bit like saying you understand gravity and can write a solution to the three-body problem, without ever stating "F=G.M1.M2/R" - except that gravity really does exist. It's the most obvious hocus pocus. I'm pretty sure these guys knew that - you're not just falling for the same seduction that they did, you're being hoodwinked by them.   

       *item 14 on the Whacko index, incidentally - score 20 points.
MaxwellBuchanan, Mar 17 2011

       //laws apply smoothly//   

       Coming down to the level at with QM effects are significant, space is quantised - you cannot measure length or mass or time independently, accurately and continuously, so the effects the laws predict have some stepwise discontinuities.   

       Observations seem to corroborate these predictions, that is why they still remain in the textbooks as "LAWS" - as if it is some bulky tome that God or Yahweh or Shiva refers to when they have to arbitrate between the alternate paths a photon and an electron have to take after having interacted.
neelandan, Mar 17 2011

       [MaxwellBuchanan], we are using different definitions of "step changes". These things in QM are not about different behavior after taking the step, it is about NO behavior DURING the step. An electron making a quantum leap does so apparently instantly. This particular step is simply a change between orbits; so obviously it is in orbit both before and after the step-change.   

       You are wrong, therefore, to misinterpret things I've said, to make it seem like I've said something else. Where is there a macroscopic step-change in my statements about an exponential curve associated with jerk? Where is there a macroscopic step-change when I said words to the effect that the consequences of small jerks have to be minuscule to have remained unnoticed, while jerks large enough to make a detectable difference tend to also be large enough to wreck the measuring devices?   

       Your blather about how large effects of large jerks should have had obviously detectable differences from Standard Theory (like some Momentum going unaccounted-for) has not once been associated with anyone actually collecting detailed hard data about the Momentum in such events. Because so far as I know, there aren't any measuring devices able to survive the experience, to obtain that data. Go ahead, name one such measuring device! Because without one to get the data, OF COURSE such jerks have gone un-analyzed, etcetera.   

       Next, you haven't said anything about WHY Davis and Stine and co. would tell lies. (Only if they are lying can someone become hoodwinked by them.) You haven't even offered evidence that any of their statements are flawed, much less fabrications. ALL you have harped about is how nobody else has bothered to try to replicate the things that led to the claims they made (well, there's that modern remake of a Dean Drive that you are dismissing without seeing it...)..   

       Such harping means nothing! Because such replications --or other applications/extensions derived from their claims, such as my artrr, or the "Hertzian gravitational wave test" described elsewhere-- are the only ways to find out what the truth really is. Their statements are merely claims, which are waiting for more support than the stuff they claimed was relevant evidence.   

       Or those claims are waiting for negative evidence, which would disprove them. You seem to think that NO evidence equals negative evidence, and about that, you or anyone else thinking that way would be quite wrong. It's not the way Science is done!   

       Finally regarding equations, it is not impossible that the thing you asked about might exist. At the end of Stine's article he mentions that Davis' research group wrote an unpublished series of papers. If the papers could be tracked down, perhaps the equation you want is in one of them.
Vernon, Mar 18 2011

       This is circular reasoning.   

       Nobody has yet observed, or disproved the existence of, the Invisible Pink Unicorn (IPU).   

       Therefore, the IPU exists.   

       Similarly with the flying Spagetti Monster, who created the whole world.
neelandan, Mar 18 2011

       //Where is there a macroscopic step-change in my statements about an exponential curve associated with jerk?// That was exactly my point, a while back! There _is_ no step change in your jerk theory (I also say there are no step changes of the relevant sort in QM, but that's a digression prompted by earlier annotations). Therefore, jerk-related phenomena should appear to _some_ extent in many other systems.   


       //not once been associated with anyone actually collecting detailed hard data about the Momentum in such events.// Perhaps you underestimate materials scientists! There is a huge, vast, immense and enormous literature dealing with the engineering problems of things like car pistons and artillery shells, explosive bolts, bomb-casings and a thousand other things where the jerk should more than high enough to show this "weird" effect. There really, truly is. (You're right about the blathering, though - we'll have to call that one a draw.)   

       //WHY Davis and Stine and co. would tell lies// OK, the why. Possibility 1, they believe they've found something, and want to believe it, which makes it incredibly easy to deceive oneself. After that, deceiving others is an inevitable consequence. Possibility 2, people lie for lots of reasons, which I'm sure are pretty self-evident. However, I'd prefer to think it was option 1 in this case (and, likewise, in the case of the "herbal fuel" guy). If someone tells me that they can levitate using cheese, I may not know their reason for saying this, but I am frankly going to need a little more than their word.   

       //You seem to think that NO evidence equals negative evidence// I beg to differ. There is a wealth of evidence (only over the last two or three centuries, but hey) that the behaviour of shock-waves is fully accounted for by well-known mechanisms. There is also a wealth of negative evidence, in the sense of these "jerk" effects failing to be observed in many situations where their effects should be very clear.   

       To follow the point made in the anno above: OK, suppose I say "dropping a bismith rod into custard at exactly 287K will cause it to emit a gravitational wave. I know this because, when I tried it, the hard-drive on the computer nearby suffered an inexplicable head-crash". I suspect nobody has tried this, there's certainly no reason to expect it to happen. Nor has anyone considered it necessary to disprove such a claim. It doesn't mean I'm right. I may not know a lot about how science works, and I think it's inappropriate to "pull rank", but there are many people out there who really do have a good idea about how science works, and who walk away from this kind of stuff. For myself, the best I can say is that science has kindly kept me in employment for the last 30-odd years, and I expect any day now to figure out how science works.   

       //a group of unpublished papers// Now, that is a shame. Given that they published so many papers on this (as opposed to, say, just writing them and not going through the trouble of having them peer reviewed by a journal), it's just another piece of tear-jerkingly bad luck that these critical papers describing the basis of this phenomenon didn't get into press.
MaxwellBuchanan, Mar 18 2011

       //tear-jerkingly bad luck that these critical papers describing the basis of this phenomenon didn't get into press//   

       Maybe they were just waiting for a call-for-papers in a special issue on the subject?
Jinbish, Mar 18 2011

       [neelandan], don't be silly. We are talking about actual hardware that is not ridiculously difficult to put together, and people who are too comfortable in what they THINK is true to bother to put it together, to see what is ACTUALLY true.   

       [MaxwellBuchanan}, I was in a hurry and the thing you quoted (below) wasn't actually what I should have said (edited above).   

       You also apparently ignored what I wrote in a previous annotation, about ordinary jerk-events being associated with the flattest part of the curve, thereby being about as easily detected as the change in mass that happens when carbon and oxygen combine chemically. OK, that's a bit of an exaggeration, since Stine's Phaser gadget would qualify as revealing a jerk-related phenomenon under reasonable conditions.   

       The engineering literature you mentioned has "problems" with jerk-related phenomena? DUH! The whole point of what Davis worked on is that it could be a generic Answer to all those problems.   

       As for your Reason 1 for lying, it is not considered lying when somebody says something false that they sincerely believe is true. Case in point, are you lying when you say words to the effect that jerk-related phenomenon have no consequences such that replicating Stine's Phasers would be a worthwhile effort? You are simply stating what you think is true, whether it actually is or isn't.   

       Likewise, I'm not lying when I say the issue should be put to the test, to find out what the truth really is.   

       Next, recall that I wrote in another annotation, "it might be interesting to see what a physicist might say about the degree to which a gasoline engine piston is "overengineered" with respect to what Standard Theory says should be adequate." Your engineering journals are engineers talking to each other, not talking to physicists.   

       Similarly Stine's ejection-capsule team had the task of reducing the amount of jerk that would be experienced by ejected pilots, and the attempt to reduce it led to parts breaking. THEIR solution was to show that the pilots could withstand more jerk than had been originally specified, allowing the hardware to reduce jerk less than originally specified, and thereby not break. In other words, the engineers found a way around (a way to ignore) what the physicists had to say on the subject, about what stresses the materials could tolerate. And materials engineers have been doing equivalent stuff for all those centuries you mentioned.   

       Do you see how the above example, in reducing the amount of jerk experienced by the materials, allows those materials to stay near the flatter part of the curve of jerk-related consequences, where Standard Theory is adequate? So, one way to validate part of what Stine was talking about is simply to try to build an ejection capsule in accordance with the original specifications!
Vernon, Mar 18 2011

       [Vernon] you're right, I'm too busy working on what I THINK I know because, so far, this tactic has proved more successful than working on things which I THINK I am pretty certain will be a waste of time and money.   

       However, this is no reason for you not to press ahead. In fact, for me, it's a win/win if you do. Either you amaze everyone (including me) and demonstrate some astonishing new physical concept which will transform much of physics and make life more interesting for everyone; or you fail, which costs me nothing and let's me say "told ya".   

       It's like watching Eddie the Eagle - you think he's going to break his neck, but there's that one-in-an-Avogadro chance he'll break the record instead, and either one is great if you're a spectator.
MaxwellBuchanan, Mar 18 2011

       Vernon has claimed that accelerating mercury doesn't work.   

       He hasn't commented on my FARTRRRR-R-R-R, so I can't really get his take on accelerating ions. The premise here seems to be that (1) it has to be a rigid body and (2) it has to be stressed.   

       In other words, the effect which is non-existent in a liquid or ion suddenly comes popping up with a rigid body, and that too when its strain crosses over some sort of a threshold.   

       What is the magnitude of this threshold? Why does stressing a rod mildly not provoke a gravity wave, but stressing it higher than this threshold does cause a gravity wave, which is assymmetrical so that a net reaction is produced?   

       A rigid rod is an assembly of ions and electrons, so collecting ions and electrons into a rigid piece of matter (not a liquid) somehow imparts a magical quality of capability of originating assymetrical gravity waves while stressed above a magical threshold.   

       Unicorn tears, unobtainium, the invisible pink unicorn, all devised and lorded over by his noodliness, the spagetti monster.   

       Pastafarianism is at least amusing.
neelandan, Mar 19 2011

       [neelandan], there are two aspects of the forces applied to your gadget, and you have only focused on the ions. But the framework holding the impacted ion target, and which also holds the devices that accelerate the ions, also experiences forces. The real problem is whether or not the impacts of the ions are "large" enough, with respect to a particular definition of "large".   

       Consider Dr. Joseph Weber's gadget (invented in the 1960s) to detect gravitational waves ("resonant mass antenna" or "Weber bar"). The assumption is that a passing wave would cause the mass of the antenna to experience some measurable stresses. (Note this means the gravitational wave will lose a bit of energy in the process, if only because the mass is not a perfect spring.)   

       Next, in Quantum Mechanics there is a fairly powerful Rule called "Time Reversal Symmetry", which states that for most SIMPLE events (usually involving only two or three interacting things --in this case one mass and one gravitational wave), if a recording is made of the event, and the recording is played backward, then what you see would also be an allowable event.   

       So, if Time Reversal Symmetry is applied to the operation of a Weber bar, it logically follows that stressing a mass should result in the production of a gravitational wave. (This is one of 5 different starting points in Physics that might connect a stressed mass to gravitational radiation.)   

       However, note that Weber bars are "large" in the sense that they occupy a fair amount of Space. Atoms distributed throughout that Space are all moved by stressing the mass, and to whatever extent they can be called "connected" to the "fabric" of Space (such that they would move if a gravitational wave passed by), that is the extent to which they would sort-of pull on Space, working together to generate a gravitational wave.   

       I don't see that your ion-impacts are large enough in the sense of involving enough Space to cause any significant gravitational waves to be generated. Sorry. But note the similarity between this and the bottleneck in [MB]'s mercury gadget --only THAT place gets stressed, and not the whole mass of mercury. I've added a link that might be relevant.
Vernon, Mar 19 2011

       //if Time Reversal Symmetry is applied to a Weber bar, it logically follows that stressing a mass should result in the production of a gravitational wave. //   

       How big or small a gravity was did Weber's bar manage to detect? And what were the measured stresses?
MaxwellBuchanan, Mar 19 2011

       [MaxwellBuchanan], Weber's results are controversial. Many physicists think that what he actually detected were sound-wave vibrations, due to inadequate isolation of his detector from the outside world. And some simply say that gravitational waves are too feeble to be detected at all in that manner. But some persevere; while Weber died a bunch of years ago, other researchers still work with updated versions of his gadget (fairly easily found in a Web search). One is in Louisiana (USA), and is called ALLEGRO (an acronym).
Vernon, Mar 19 2011

       always stops before we get the meat. AND, AND????
WcW, Mar 19 2011

       [WcW], I've provided enough data that you should be able to find more details without trouble. That way you can directly disbelieve those sources, instead of disbelieving what I might say that those sources say. :)
Vernon, Mar 19 2011

       //Weber's results are controversial.//   

       Dang, [Vernon] you just have the worst luck. You had an almost reasonable argument back there - about microreversibility, and about a gravity-wave-detector acting as a gravity-wave-generator if reversed.   

       And then, gosh darn, if the gravity-wave detector itself doesn't let you down by being "controversial".   


       By the way, I can see you don't like my non-reactionless mercury-based arrangement, nor [pocmloc]s comb.   

       However, help is at hand. The essence of your device is the difference between sudden and gradual forces, and responses thereto.   

       I am awaiting the delivery of some new envelope-backs to complete my calculations, but I my initial reckonings suggest that a dilatant substance (such as, ooh, say, maybe custard) will be ideally suited to creating an ideal "reactionless drive".   

       Custard Pow(d)er to the Stars!!!
MaxwellBuchanan, Mar 19 2011

       Yes, my comb is ganshing its teeth due to its unwarranted neglect. Within a hairs breath of proving the theory once and for all. Perhaps people just couldn’t handle it. They will regret their folly. Cue a large tear, as if parting, but brush it away. We will rise above this bar before us. Raise a glass to the bald pioneers!
pocmloc, Mar 19 2011

       It will be my FARTRRRR-R-R-R that would be powering that pogo stick.
neelandan, Mar 19 2011

       [MaxwellBuchanan], I'm not aware of any physicists disagreeing with the idea that if a gravitational wave passes through a mass, the mass will be distorted (because the Space it occupies gets distorted).   

       The disagreements with Weber are about the magnitude of the effect; they think that it is too small to be detectable by a Weber bar, unless the device is located MUCH closer to the origin of the gravitational waves (Earth is astronomically distant from all ordinary sources, of course, with the Inverse-Square Law making them rather feeble because of the distance they must travel to get here).   

       Anyway, it remains logical that if the mass can be distorted at all by a normal very feeble gravitational wave (Event A), then Time Reversal Symmetry should be relevant. (However, I do need to say the notion of applying TRS to this interaction is, so far as I know, original with myself. Perhaps someone more expert will find a reason why TRS shouldn't be relevant.)   

       Now, think about the consequences of distorting a mass by some ordinary means, and presuming (thanks to TRS) a gravitational wave gets produced (Event B)...   

       If Event A yields an extremely small distortion, then what magnitude of gravitational wave should be produced when we cause a large distortion for Event B? This is why I described a "Hertzian" experiment on the artrr page (an anno dated Feb 09 2011) --we might be able to make a strong-enough gravitational wave that it could be detected by a nearby Weber bar (our distortion event would be astronomically closer than all those other sources, see!).   

       Only one way to find out, of course!
Vernon, Mar 20 2011

       Oh boy. <shakes head> You mean that you believe you can apply a stress to an object, and cause a distortion of the space the object occupies? With said spatial distortion resulting in a gravitational wave? I really, really hope I'm misunderstanding you.
lurch, Mar 20 2011

       OK, so the argument is that, if a gravitational wave causes distortion, then distortion should cause a gravitational wave.   

       This raises the questions:
(a) Is micro-reversibility applicable in this situation, or are we dealing with a "macro" situation, which is not symmetrical in this way? (For example, I can't broadcast a TV signal from my TV set simply by projecting a moving image onto the screen.)

       (b) If gravitational waves cause distortion, that doesn't tell you whether "jerk" has anything to do with it. In other words, it says nothing (afaict) about the rate of distortion; your ATRR says (and depends on the idea) that "jerk" and "steady loading" produce different effects.   

       (c) At what speed are gravitional waves supposed to propagate? If it's "c", then you may find that the only way to produce gravitational waves from a stressed object is if the stress propagates at the speed of light. Since this is impossible, you're screwed (I'm not sure of the factors in this argument, though).
MaxwellBuchanan, Mar 20 2011

       Have we even defined “jerk” yet?
pocmloc, Mar 20 2011

       [MaxwellBuchanan], please recall that I said that Time Reversal Symmetry applies to most SIMPLE interactions. A breaking vase is complex because lots of individual and separately-behaving pieces are part of the overall interaction event. Ditto with the workings of a TV set. But your car on the road is something you know you can drive in reverse to (in theory) exactly backtrack some forward motion --the interaction is between car and road, where the wheels make contact, so in that sense it's simple, see?   

       [pocmloc], jerk or surge has been defined as a rate-of-change of acceleration, exactly as acceleration is a rate-of-change of velocity. If this is associated with producing a gravitational wave, then it would be a shorter-wavelength higher-energy wave than anyone could expect would be produced by gradually stressing something.   

       [lurch], in Nature most connections are two-way. Why should a distortion of Space be able to cause a mass in Space to become distorted, but not the opposite? An analogy is a toy boat on a pond, which you know will physically respond to waves on the water --but you can physically manipulate the boat to make waves, too.   

       And remember that I've said there seem to be 5 different starting points in Physics that can link distorted mass to distortions of Space (gravitational waves). One of the others is quite straightforward, from General Relativity (Jeffery Cameron's paper). Dr. Davis' modification to Newtonian Mechanics is another (albeit this consequence was devised to Conserve Momentum).   

       A different way of reaching Dr. Davis' conclusions was devised by another fellow we've not talked about much either here or on the artrr page, a Hermann von Schelling (his work is mentioned in Stine's article, and I used the reference at the end of the article to obtain a copy). Davis' primary assumption is that some part of an applied external Force should be associated with the initial change-of-acceleration of a mass (jerk), before actual overall acceleration begins, and von Shelling's primary assumption is that when an external force is applied, the whole mass cannot instantly respond to it.   

       The fifth way I've mentioned on this page, involving the Woodward or Mach effect, so I need not repeat it here.   

       A SIXTH notion, peripherally related, involves the result of a hypothetical interaction between a negative mass and an ordinary mass (described on the artrr page). The result is some "loose Momentum" not associated in any ordinary way with Mass or Energy. It does not have to move at light-speed, and MIGHT be useful to explain how Gravitation could work in terms of Quantum Mechanics.   

       That would mean that "loose momentum" is actually a variety of gravitational wave. Can anything else generate that type of gravitational wave, carrying significant Momentum and not moving at light-speed? My guess is, the five other concepts above!
Vernon, Mar 20 2011

       //jerk or surge has been defined as a rate-of-change of acceleration//   

       If jerk really is simply ROCOA, we can quantify it as ms^-3. Then we can calculate its size in various scenarios, and use it in our equations.   

       So no more talking about scenarios “with jerk” and “without jerk”! The latter is impossible!
pocmloc, Mar 20 2011

       // Hermann von Schelling//   

       Damn, damn and damn. I missed that one on the Revised Whacko Index. I'll now have to add:   

       "17. One or more of the people involved in the invention (or the underlying theory) have names that could have come from “Young Frankenstein”. Examples include “Dr. Kippermeister”, “Professor Hackenburger” or any name containing “von”. Score 2 points for each such name; score an additional 4 points for every name that begins with "Baron"."
MaxwellBuchanan, Mar 20 2011

       I don't quite believe I'm actually getting involved in this but...   

       [Vernon] Nobody's contesting, has contested or will contest that if you apply a force to an object, that it will take awhile to distribute that force through the object. The exceptions of course are forces which do apply to the entire object: stuff like gravity.   

       And if you're going to do something with reversible causality, the easiest one is a snooker shot.   

       Meanwhile if your experiment requires an acceleration on the object (as opposed to a velocity) then that implies that the gravitational "aura" on an object has a lag function.
FlyingToaster, Mar 20 2011

       [pocmloc], yes, that's just what Dr. Davis did, except to make the equation balance ("dimensional analysis") it is necessary to add a quantity of time to the expression you posted. That quantity of time is the time it takes the jerk to propagate through the object being jerked (usually less than a millisecond in ordinary objects). Read his "article that started it all" (linked on the artrr page). I'll be a bit more explicit below.   

       [MaxwellBuchanan], while von Schelling was a German, he worked in the USA for General Electric Research. (And it happens that E.L. Victory was from Iran, so?) Do you really think it is rational to arbitrarily declare those not of Anglo-Saxon descent to be "cracked"?   

       [FlyingToaster], the problem here is that while nobody really contests the notion, the Standard Newtonian Equation F=(M)(a) does not accommodate the notion, at all! Therefore those who insist that Standard Newtonian Mechanics must be absolutely correct in its results ... may be more "cracked" than Dr. Davis, who modified the equation to ENSURE it accommodated the time it takes an object to fully respond as a whole to an externally applied force (via jerk).   

       The simple version of his equation could be written F=(M)(a) + (M)(j)(t), where j=jerk and t=time-of-propagation as mentioned above. So, Davis is saying that when a Force is applied to a Mass, a smallish PART of it is "used up" to cause the Mass to jerk into the acceleration associated with the traditional form of the equation (and the rest-of/main-part-of the applied Force).   

       It should be obvious that if a significant fraction of the applied Force was devoted to causing jerk, it would have been Officially Noticed long ago. But when the Force is quite large, then even that small part devoted to jerk can have significant consequences (things like measuring devices break, that the Standard Newtonian Mechanics equations say should be strong enough).
Vernon, Mar 21 2011

       Sooooo then if you don't mind me paraphrasing...   

       The assumption is that a mass has a corresponding gravity component that isn't directly affected by standard physical force. However it's "glued" to the mass. If the mass is physically accelerated then the graviton lags back a bit. The idea then is to apply another force at an angle to the accelerating particle in order to shake off the graviton (or a portion thereof).   

       Yes ?   

       If so then I'd be thinking of a way to "crack the whip". Ahh...   

       A cyclotron: particles swinging about magnetocentrifugally at near c. Thus the "phase angle"(if this is what it means) of the graviton would be a full 90 degrees to the motion of the particle, ie: it would be sticking out the side barely hanging on by its fingernails.   

       A collision with another particle should easily cause a gravitic wave to fly off, presumably screaming "wheeeeee..." or "ohshitohshitohshit...".
FlyingToaster, Mar 21 2011

       Somebody should re-analyse all that data from particle collision experiments, looking for gravity waves that escaped and therefore caused a net change in momentum with the predicted 3 deg angle.
neelandan, Mar 21 2011

       I'm not sure, but I rather suspect people have already analysed collision data rather carefully.   

       [Vernon] re. the names - I got bored with rational argument and thought I'd try something more informal.   

       As my great uncle Lucinda used to say: "Just because nobody agrees with you, it doesn't mean you're right."
MaxwellBuchanan, Mar 21 2011

       //already analysed collision data rather carefully//   

       So banging particles together at relativistic speeds does not result in gravity waves carrying away momentum - we would have seen it in the results otherwise.   

       Somebody in the moon believes that banging together great big assemblages of particles do. And that would be very much slower than relativistic speeds - no earthy mechanism can accelerate masses anywhere near the speeds found in the particle beams from accelerators.
neelandan, Mar 21 2011

       I can't believe that this didn't occur to me before.
What's the value of D? It's the delay time for the propagation of the shockwave - right?

       M16 bullet: Mass = 4g, Length = 0.0045m M16 rifle:
muzzle velocity = 948m/s

... Er... hold on.

       Nah. I'm not doing this donkey work. I was going to describe the moment that a bullet is propelled from the chamber of a well known rifle and use some figures to see the kind of 'jerk' that results. Only problem is, with a little research it became clear that the gunmakers of this world have put a lot of effort into this kind of thing. They don't seem to have discovered any effects that they can't explain via friction (although I haven't found any links that describe the effects of general relativity in a gun chamber).   

       I'll pop by now and then to see the next iteration of "WTF?" met with "someone else says" - it is entertaining if nothing else.   

       EDIT:: I actually did the donkey work because I was procrastinating in my office. With a bullet mass of 4g, length of 4.5mm, estimated acceleration at 10^6m/s, propagation delay of D=(1/10^5)s (from "the article that started it all"), and estimated time period that change of acceleration takes place as being 10^-5 s, we have:   

       F = 0.004*10^6 + 0.004*0.0045*10^-5 *{10^6-0}/10^-5
F =4000N + 18N
That's an extra force of 0.45%. I'd say that is significant enough to have been noticed before...
Jinbish, Mar 21 2011

       [FlyingToaster], so far as I know, various subatomic particles like electrons or quarks don't experience jerk, because to the best of our ability to measure them so far, they have sizes indistinguishable from mathematical points. It is combinations of particles that experience jerk, as forces propagate from one particle to another, through the linkages in those combinations.   

       Also note that for combo-particles like protons (made from 3 quarks), the interior propagation speed could well be nearly lightspeed, so between the small size and the fast propagation, the amount of jerk becomes very tiny indeed! And so we sort-of need to deal with macroscopic objects, when discussing jerk.   

       [Jinbish], thank you, but I'm not sure how you can think that half-a-percent counts as a "significant fraction". Depends on the chosen definition of "significant, I'm sure.   

       Anyway, I want to ask you about your chosen method of computation. Is not the magnitude of Force known in advance (computations involving explosive material), before you compute the bullet data? In other words, if you know that the Force is 4000N, then the final speed of the bullet would be less than computed by F=(M)(a), because of the portion of that force used for jerk.   

       One way to test it, though, using the calcs you did come up with, is to take another bullet and remove exactly half of the explosive material. Then you could assume that the force of its explosion would be half of 4018N, or 2009N. Now measure the actual speed of the bullet when the cartridge is fired. If the effects of jerk follow a curve, then there would be a different muzzle speed than would be predicted by using F=(M)(a) only.   

       For best results, the measurements should be done in a vacuum chamber, of course! Start with a regular bullet and measure its muzzle velocity (should be different from "normal" when it doesn't have to fight air resistance), then do the computations to make predictions (one using jerk and one without), then fire the half-explosive bullet and measure its muzzle velocity.
Vernon, Mar 21 2011

       Oh for goodness' sake.
MaxwellBuchanan, Mar 21 2011

       //so far as I know, various subatomic particles like electrons or quarks don't experience jerk// But you said jerk was rate of change of acceleration. These are contradictory statements.
pocmloc, Mar 21 2011

       Protons are what are normally "fired" in a cyclotron.   

FlyingToaster, Mar 21 2011

       Sub-atomic particles do experience jerk. They don't experience the propagation of jerk.   

       Jinbish is pulling in some approximations to produce a reasonable result. The force required to produce those accelerations would either be 4000N if we ignore your theory or 4018N if we don't.   

       That difference is half a percent or 1 part in 200. That's plenty for modern instruments to detect and therefore significant. I would suggest that any undetected forces in something like a bullet being fired would have to be no greater than 1 part in 20000 to have gone undetected to this point.   

       Jerk is not new, it is not unexplained, it does not exhibit unusual behavior. It is simply the third derivative of position with respect to time, and it figures in a lot of fairly complex math that 99% of the time you can ignore because it makes life easier to do so.   

       Jerk is the reason, however, that sine motions are popular for motors and the like in machinery, however, since all the derivatives are smooth. It hasn't been ignored, just left out of calculations where it isn't needed.   

       Regardless, halving the propellant won't produce half the muzzle velocity due to expansion space in the chamber, differing combustion properties, differing expansion patterns, differing frictional losses, etc. This is not simple math, but it has been done, without producing any unkowns of a scale that would validate this idea.   

       It's that simple.
MechE, Mar 21 2011

       Hi [Vernon], all I did was take the formula suggested in your references and put some meat on the bones... which is more than you appear to have done. No values, no numbers - no quotations of values from any of the papers that apparently exist.   

       And by the way, you don't need the actual value of force - that's irrelevant. The only thing that matters is the proportion of contribution by any suggested jerk. And 0.45% is MASSIVE. With a muzzle velocity of 950m/s, a .45% change would mean an extra 4m/s. As MechE says (and I must be way down the list of HBers qualified to attest to), ballistics manufacturers and testers can measure that easily.
Jinbish, Mar 21 2011

       [pocmloc], it appears that I misspoke, and [MechE] said it better. Note that you have to have a propagation of jerk before a propagation time can be a factor in various calculations.   

       [MechE], another way to incorporate a significant difference, less affected by the paramenters you mentioned, is to modify the bullet. If a normal bullet is, say, steel-jacketed lead, just use a variant bullet, same size, that is steel-jacked aluminum. (and maybe another that is steel-jacketed "depleted uranium", significantly denser than lead)   

       To both [MechE] and [Jinbish], there is still something you haven't said. Have those arms manufacturers simply fired charges and measured muzzle velocities, or have they computed what the muzzle velocity should be from the charge? The first would mean they would never need to worry about whether or not jerk was a factor, see? They (their engineers) can simply say that those are the FACTS, the measured charge and the measured muzzle velocity (and who cares what mere theory says?).   

       What I'm saying is, you need to know the actual Force in order to find out if the actual acceleration (and final velocity) matches some computed amount. OR, you need a way to actually measure those 4000 or 4018 Newtons, to see if what you measure is what you have computed from the measured rate of acceleration, both with and without jerk.   

       SO, have they done that?
Vernon, Mar 21 2011

       I don't see why you're ignoring centrifugal force as a useful component. In cyclotrons they usually use entire nuclei. Or, if that's to nanoscopic for your tastes, a centrifuge would not only allow you to use accelerations up around the tensile strength of the materials, but also allow the term "circle jerk" to be introduced into the conversation (or "jerked around", also apt).
FlyingToaster, Mar 22 2011


MechE, Mar 22 2011

       [Vernon], the point is that the difference of about 1 in 200 would be significant enough for someone to notice that F=ma didn't entirely describe the scenario (even taking friction, heat-loss, propellant effects, etc.).   

       You're trying to suggest that the force due to jerk has somehow been overlooked because of the inaccuracies in measuring applied force. All this time we thought that the 4018 Newtons applied by the gas expansion due to propellant combustion was responsible for the just acceleration - but now it turns out the we've lost 0.45% creating jerk. Our bullet isn't as fast as we first thought...   

       Sorry. The arguments presented for adding jerk to F=ma just don't add up. I not trying to persuade you of that fact - I'm just saying that is my conclusion.
Jinbish, Mar 22 2011

       In the same vein, one of the "observations" that prompted this whole goose-chase was that ejector-seat components failed "inexplicably" - due to some mysterious "jerk" component.   

       Nobody here has addressed my point, which I will make again: an "inexplicable" failure, in the face of the usual conservative engineering safety factors, would mean an "inexplicable" loading of roughly similar magnitude to the "predicted" loading. Not 0.5%, not 5% - more like 50% or greater.   

       Vernon- are you suggesting that the ejector seat components were so _precisely_ engineered, with so _little_ safety factor, that a "mysterious" 0.5% increase in force was enough to break them? Do you know of any other engineering structure which will repeatedly fail if its designed load is exceeded by 0.5%?   

       So, this is plainly ridiculous. The fact that an alleged engineer allegedly used this alleged incongruity to allege that there was an allegedly mysterious and hitherto-unobserved (yet colossal) new alleged force means that what we are dealing here is some mixture of fantasy, stupidity and fraud.   

       p.s. this discussion is probably the world's most protracted example of the conversation of momentum.
MaxwellBuchanan, Mar 22 2011

       [MechE}, something I forgot to ask about relates to the quantity of propellant in the charge. How precisely is this measured? For lab tests I'm sure they can be quite precise, but for mass production, there will be some tolerance of variation in the quantity --perhaps even more than half a percent....   

       [MaxwellBuchanan], while I don't know how large the "yokes" were that Stine talked about, I'm quite sure that the cables he mentioned were considerably longer than the length of a bullet. Did you not notice the (t) factor in computing the magnitude of a jerk-related Force? That's why I wrote in several annos here about how your mercury experiment has a problem, in that there is no propagation of jerk throughout its mass (only affects bottleneck), and so no significant jerk-related propagation time --and therefore no significant jerk-related Force.
Vernon, Mar 22 2011

       Doesn't matter. You're still arguing that your "mystery" force is of the same order as the "conventional" forces, under fairly mundane conditions. To argue that this huge "mystery force" has eluded physicists and engineers for decades is madness.   

       (No disrespect to [madness]).
MaxwellBuchanan, Mar 22 2011

       Why does that matter? If it doesn't show up under laboratory (design testing) conditions, why does what happens in the field matter?
MechE, Mar 22 2011

       [MechE], because there are lab tests and then there are other lab tests. One group of such tests involves the bullets that will be used in the field (reliability testing, for example), and these will accept as normal a certain variance in muzzle velocities.   

       Other tests are for such things as "proofing" a gun barrel, to ensure it can withstand lots of firings (a proof charge is always significantly more than standard charges). I doubt they care what the muzzle velocity is in these tests.   

       The most relevant type of ordinary tests that I can think of involves a "new" bullet. The manufacturer wants a particular gun to fire a particular bullet at a particular velocity, for a particular purpose (we all know you don't NEED the same gun&bullet to shoot a rabbit as you would certainly need to shoot a rampaging bear). So, enter the lab to discover what charge causes the specified bullet mass to have the specified muzzle velocity. This seems to me, though, to be more of a trial and error process, AFTER initial calcs are performed to find the ballpark quantity, than to insist that the calcs must be exactly correct in specifying the charge needed.   

       Do you happen to KNOW which way they go about it? Because the kind of tests that your descriptions have implied, also imply that various people had doubts about F=(M)(a) --you don't normally do tests to that degree of accuracy unless you want to show how valid (or not) the equation is!
Vernon, Mar 22 2011

       All this talk of jerk (da/dt or d2v/dt2 or even d3D/dt3).
What about shudder (d2a/dt2), reverb (d3a/dt3), or boink (d4a/dt4)?
neutrinos_shadow, Mar 22 2011

       You do tests like that to verify that your test piece is behaving the way the equations say it should, and to figure out why it isn't if it isn't.   

       The net result of this is that engineers spend a fair amount of time determining exactly why an object launches the way it does, or stops moving the way it does (e.g. Crash and drop tests). If something doesn't match the predictive equations they go back over the device until they figure out why it doesn't. So during these thousands and hundreds of thousands and millions of tests over the past few centuries, no one has found a force on the order of magnitude you're talking about that they haven't been able to determine a direct and physical result for.   

       Whether it's a gun firing, a rocket/missile launching, a car crashing, or the implosion device on a nuclear weapon, it has been analyzed like crazy, and there are no unexplained effects on the order of .5%, .05%, or even .005%.
MechE, Mar 22 2011

       Actually, on the same lines, [Vernon], you're hoist by your own petard.   

       You claimed (somewhere a few chapters back) that the ejector-seat components failed "inexplicably" because of jerk.   

       One of the standard tests in materials science is a work-of- fracture test. It's done (or used to be - they probably have higher tech now) by putting a sample of the material in the path of a very heavy big swinging pendulum. The pendulum hits the sample and snaps it and, as a result of expending energy, loses height. The loss of height in the pendulum's swing can then be used to calculate the energy needed to fracture the test-piece.   

       If being hit by a big swinging weight isn't a jerk, tell me what is. Yet none of this alleged jerk-related mystery- force has been found.   

       Truly, [Vernon], this is like looking for Vulcan on the grounds that we might not have noticed it before. (Incidentally, the reason people looked for Vulcan in the first place was to try to explain a fractional percentage of discrepancy between the predicted and actual orbit of Mercury; this discrepency led ultimately to general relativity. People have been making very sensitive measurements for centuries.)   

       Another question. Many hundreds of people have seen the Loch Ness Monster. People have even photographed "it", and articles on its possible existence have even appeared in peer-reviewed journals. Its existence doesn't even violate any laws of physics, nor even the lesser laws of biology. In other words, the evidence for the Loch Ness Monster is far more abundant and thorough than for this weird force of yours.   

       I don't believe in the Loch Ness Monster. [Vernon], do you?
MaxwellBuchanan, Mar 22 2011

Leave Nessie out of this... and what's Hannibal from the A-Team got to do with it?
Jinbish, Mar 22 2011

       [MechE], Stine wrote all about how engineers will come up with various "finagle factors" to explain discrepancies in the equations from the actual measurments. But physicists would do it differently, so it is physicists who need to do these gun experiments.   

       [MaxwellBuchanan], kindly be more accurate with the stuff you claimed I said. And don't be afraid to go back to the source, which in this case is Stine's article. The snapped cables and stuff that Stine encountered was indeed inexplicable at the time. Later, he encountered Davis and Dean, and sometime after that is when Stine got the explanation of jerk being significantly involved.   

       As it happens, I do know about that fracture test involving a pendulum, though this is entirely because about the time I first posted the artrr Idea, I wanted to find an on-line image for Stine's type of pendulum test, and the only kind of pendulum test that came up in my searching was the fracture test (so I finally stopped looking and ended up posting my own sketch).   

       Note that the nature of the fracture test is that it does NOT involve long lengths of test-material, where the propagation time of a jerk has a chance to become a really significant factor (as it was in the case of Stine's cables).   

       If you want to see significant jerk in a fracture test, simply attach a long length of the test material so it dangles from the underside of something like a special pile driver (perhaps with an extra weight at the bottom, but not really necessary if the length is long enough). The attachment should be a clamp-type or some other non-bolt-through type, to avoid weakening the material at that point.   

       Then let the whole assembly drop for some appropriate distance (might be less than 1 meter; the longer the dangling length, the shorter the drop can be), after which the "driver" impacts something that makes it immediately stop moving. The driver of course has to be wide enough so that it can hit the stops while the test-material still dangles freely beneath it.   

       The most likely place the dangled test material will break as a result of this jerk is near the attachment point, since it will receive the most stress. But will its breakage match Standard Newtonian Calculations? If Stine wasn't lying about his cables, then they won't.   

       But of course nobody will bother to test for breakage this way, since it would be significantly more expensive than the standard pendulum test. Tsk, tsk!
Vernon, Mar 22 2011

       Ironically, an experiment not unakin to the one you describe (which nobody ever bothers doing) is a standard experiment performed by several hundred thousand UK physics students every year.   

       A mass is suspended from a thread, and another thread is suspended from the mass. If the bottom thread is pulled smoothly, the top thread breaks (since it bears the greatest load). If the bottom thread is jerked, the bottom thread breaks (due to the inertia of the suspended mass).   

       They probably don't realize what kind of forces they're meddling with.
MaxwellBuchanan, Mar 22 2011

       Did you happen to read the last item I listed? You really don't want to fudge the implosion numbers on a nuclear device. It does very not fun things. I'm not saying it never happens. I am saying that it doesn't always happen and there are still no unknowns of this scale.
MechE, Mar 22 2011

       //the implosion device on a nuclear weapon//   

       As I understand this, it is the conventional explosive around the fission core that keeps the stuff together to make the reaction happen long enough to develop a good yield.   

       Data from the tests were used to develop a good enough computer model. So if that model is accurate enough, there shall be the term for jerk derived disappearing momentum in there, too.   

       So now we know why this hasn't made it out into the consciousness of the general public. It is a significant component in the design of atom bombs and is being kept secret by guys in the pentagon.   

       This thread is in their radar and will disappear soon.
neelandan, Mar 22 2011

       I didn't know they could use radar to detect html files!? Man alive...
Jinbish, Mar 22 2011

       That is why Vernon does not use html to describe artrr in his website.
neelandan, Mar 22 2011

       [MechE], the most important aspect of the conventional explosives used to trigger an implosion nuke is the timing of multiple explosions (all at the same microsecond). The SECOND most important aspect is the need for the substance used in the conventional explosives to generate a very strong shock wave. I assume you know that gunpowder tends to burn, not explode (unless confined)? This stuff has to be explosive in the fastest way.   

       After that, the nuclear explosion that follows tends to obliterate all evidence of just exactly what happened in-between the two events. However, it seems to me that the effect of such sharp chemical explosions, if jerk is truly a factor, is an oddball kind of balance. The overall chemical explosion could generate a bit stronger Force than they planned, balancing out any lesser-than-planned response of the material being imploded by that overall Force. (I freely admit that this "it seems to me" is a guess.)   

       [MaxwellBuchanan], I've heard of that experiment with the strings, and "inertia" is indeed an important factor. That's why my artrr has Alternating Response Times in its design; the slower response time is where inertia sort-of holds each loop still, long enough for each fast-response to move it a bit, the same direction each time. That is, the slow-rsponse and the fast-response would be working in conjuction with two completely different values of inertia, for each loop in the device.   

       Inertia is exactly why jerk must take its time to overcome a body's initial state of motion. I've not seen one single annotation saying that it is impossible for the battering ram to have two different response times, when the same total force is applied to it in two radically different ways. The corollary is that the inertia of the battering ram is not actually a constant.
Vernon, Mar 22 2011

       It is impossible for the ram to have 2 different response times when the, when the same total force is applied to it in two radically different ways.
Jinbish, Mar 22 2011

       Well, we could always do this the boring old way and someone actually tests it, then makes a working device?   

       At a rough rule of thumb, when you consider all the useful stuff we have found, be it expansion of gases (steam/gunpowder), electricity, etc usually the result is quite obvious, even with a cludged together apparatus. If the effect is really teeny, don't matter if it's there or not, it's just not usable.
not_morrison_rm, Mar 23 2011

       It is impossible for the battering ram to have two different response times, when the same total force is applied to it in two radically different ways.   

       I said it.
neelandan, Mar 23 2011

       Okay, but all the test shots on non-explosive metals with hundreds and thousands of sensors involved don't destroy all the evidence after the fact. Nor are the numbers fudged for space launches, nor any one of a hundred other things that are tested to a fault.   

       Testing happens. This effect doesn't.
MechE, Mar 23 2011

       [Jinbish], [neelandan], I'm sure you think you are being funny. If not, then how about explaining WHY my thought-experiment's extremely long battering ram can't have a short overall response-time to the multiple small distributed forces applied all along its length by the many strongmen?   

       Or perhaps you would prefer to explain why that overall response, whether slow or fast, must be equal to the response time associated with Superman's single large but equal-total-magnitude force, applied to one end of the battering ram?   

       Thanks in advance!   

       (By the way, I can be funny also. Thanks to the pair of you, I can STILL say "I don't see one single annotation saying ..." :)   

       [not_morrison_rm], I agree, and have said all along that I think an appropriate experiment needs to be done.   

       [MechE], what, no comment on the notion of hanging a length of test-material from the underside of a special pile driver-type test-device? No comment on the notion that inertia of a mass (such as that battering ram) does not have to be a constant?   

       How would YOU write an equation associating Force with a jerk that must always be insignificant, if you are at least agreed that when a Force is applied to a mass, it should experience some jerk in the process?
Vernon, Mar 23 2011

       I no longer have time to read this idea in depth at work. I wouldn't write an equation relating force to an insignificant jerk, simply because there is no need for such an equation. Jerk exists, it just isn't anything special.   

       X'=V X''=A X'''=J   

       therefore F=m*integral(J wrt Time). There, it's in the equation. Jerk describes acceleration in the same way acceleration describes velocity, and velocity describes position.
MechE, Mar 23 2011

       [MechE], it appears that you are actually saying the exact same old thing in merely different terminology. Which means you, like Newton, are actually completely ignoring the existence of jerk! Even though you admit it exists! But if it exists, to whatever small degree, it must be a describable aspect of the behavior of real masses subjected to external forces. So, try again, please?
Vernon, Mar 23 2011

       // Which means you, like Newton, are actually completely ignoring the existence of jerk!//   

       Hey, I dream of being as ignorant as Newton.
MaxwellBuchanan, Mar 23 2011

       [MechE] writes an equation giving force as a function of jerk: F=m*integral(J wrt Time), using a definition of jerk previously given by [Vernon].   

       [Vernon] please explain in more detail how this constitutes //actually completely ignoring the existence of jerk//.
pocmloc, Mar 23 2011

       There's an even more concise definition of jerk, if anyone's interested.
MaxwellBuchanan, Mar 23 2011

       So, there isn‘t.
pocmloc, Mar 23 2011

       dude this idea will never work.
WcW, Mar 23 2011

       Dude, that was precisely my objective.
MaxwellBuchanan, Mar 23 2011

       //If not, then how about explaining WHY my thought-experiment's extremely long battering ram can't have a short overall response-time to the multiple small distributed forces applied all along its length by the many strongmen?//   

       My understanding of the situation was described in my annotation involving "case iii)" on your ARTRR idea. You failed to make a case enough to persuade me why F=ma didn't apply to the thought experiment. Back then you seemed to think that the ram would compress only by the action due to Superman - and it will, but only as the shockwave travels through it and the resultant action will be that the ram as a whole will accelerate.   

       //being funny.//   

       [Vernon]: I was being facetious - not in a derogatory way - it's just that I'm not sure what else there is to say. I can't decide whether you're just doing all this as a tease and - being entertained by other baker's attempts to point out the glaring holes in the plot here, or whether you're innocently chasing a rainbow and refusing to believe that there is no pot of gold. In any case, it's been fun, cheers.
Jinbish, Mar 23 2011

       // explaining WHY my thought-experiment's extremely long battering ram can't have a short overall response-time to the multiple small distributed forces applied all along its length by the many strongmen//   

       Because you are imagining things, this idea is crazy, and springs from an ignorance of the basic laws of nature.   

       If I imagine a thought experiment whereby water flows uphill by itself, and describe it in the internet, and I try to perform it and the equipment melts before any water actually flows uphill by itself, what would normal people (no, not you, Vernon) say about the whole affair?
neelandan, Mar 23 2011

       [pocmloc], I did write in a earlier anno here that my calculus skills are nothing to talk about. However, it does seem to me that the expression "integral(J wrt Time)" is just a complicated way of writing "a" for acceleration. Which would mean his overall equation is nothing more than F=Ma, and therefore actually ignores jerk (DISTINCT from acceleration), just like Newton, as I wrote previously. I could be wrong, but so far I don't see another interpretation presented here, for what that expression means.   

       It is pretty easy to imagine a mass experiencing a temporary but constantly changing acceleration --just slowly spin up a heavy gyroscope wheel from zero to its max speed, and all during that spin-up, the mass of the wheel is continuously experiencing jerk. This is of course rather different from all those impact-related and very-short-term jerks previously discussed here, but I'm pretty sure that the basic equation F=Ma is rather inadequate to describe what the mass of the gyroscope wheel is experiencing, during spin-up.   

       [Jinbish], here I was discussing completely separate actions. That is, take Superman's shove and measure the response time of the battering ram. Then, separately, let the strongmen apply their multitude of smaller forces, and measure the response time of the battering ram. The thought-experiment was designed to get people to think that the second response time should be a lot shorter than the first.   

       If you disagree, well, THAT's what I'm asking for, here: "Why?"   

       (Because I'm quite aware that only if the second really is notably smaller than the first might it be possible for the ram to move strangely, when those forces are alternately applied at a rate faster than the slow response time --but slower than the fast response time).   

       Regarding F=Ma applying to the battering ram, the problem is that it assumes that Superman's force instantly traverses the whole length of the ram, and accelerates all of it at once --faster than the speed of light, and therefore a ridiculous assumption-- the ACTUAL propagation speed for the applied Super force is the speed of sound in the material substance of the ram.   

       And so the thought-experiment explicitly specifies a propagation time of one whole second, for that Super force to traverse the entire length of the extremely long battering ram.   

       Well, if it is obviously ridiculous to apply purely/only F=Ma when trying to describe how the battering ram responds to that Super impact applied at one end, what IS the correct equation?   

       Meanwhile, with respect to the strongmen, if they are spaced two meters apart along along the battering ram's length, then each of the forces being simultaneously applied (note "simultaneous" is allowed in a thought-experiment!) only have to propagate about one meter from the handles attached to the ram (1m forward compression and, simultaneously, 1m rearward rarefaction), before the entire ram is affected by the multitude of small forces. These compressions/rarefactions, of course, are vastly smaller in magnitude than the one caused by Superman.   

       For the strongmen, F=Ma is a good approximation for describing the ram's motion, because the time delay (1m divided by the speed of sound in the ram-substance) is very small (ordinary!).   

       I now quote you: "and it will [compress], but only as the shockwave travels through it and the resultant action will be that the ram as a whole will accelerate." --this quote implies (to me!) that you think Superman is supposed to apply more than just an IMPACT force, in the thought-experiment. Not so!   

       I know I have explained somewhere that that Super impact will cause the one end of the ram to compress, and that the more it compresses, the more it resists further compression, meaning that there must be a maximum amount of compression that will result from the impact, no matter how Super (assuming the ram doesn't break, of course, but this IS a specified part of the thought-experiment).   

       So, the end of the ram that Superman impacts will move and then STOP moving, because of the counterforce/resistance to further compression. Meanwhile the compression wave traverses the entire length of the battering ram, and the far end won't move, either, until that wave arrives (after one full second, as specified in the thought-experiment).   

       At the far end the compression wave expands the material of the battering ram so much it becomes a rarefaction wave, which traverses back toward Superman (taking another full second to arrive).   

       When it does arrive, it pulls on the end that Superman impacted, causing it to move some more, farther away from Superman. It seems to me that this will lead to another compression wave heading toward the far end of the ram...   

       Which leads me to say something I've not mentioned before: The overall motion of the ram then becomes sort-of inchworm-like, entirely due to that huge propagation time. Its motion might gradually smooth out with time (I would tend to expect it since the ram's substance is not assumed to to be perfectly springy).   

       The reason I never mentioned it before was because I was talking about an overall experiment that also included the actions of the multitude of strongmen. They are supposed to do their thing WHILE the battering ram is "holding still" (because of its inertia) while experiencing the propagation of Superman's impact. But that aspect of the thought-experiment is not under discussion just now.   

       Only the ram's response to Superman's impact, and a completely separate response of the ram to the forces applied by the strongmen, is being compared here. Note this comparison of how the ram responds can even have the forces be applied in the same direction! (Again, I'm talking about separate applications of the same total Force, but in radically different ways.)
Vernon, Mar 24 2011

       //I did write in a earlier anno here that my calculus skills are nothing to talk about. However, it does seem to me that the expression "integral(J wrt Time)" is just a complicated way of writing "a" for acceleration. Which would mean his overall equation is nothing more than F=Ma, and therefore actually ignores jerk (DISTINCT from acceleration), just like Newton, as I wrote previously. I could be wrong, but so far I don't see another interpretation presented here, for what that expression means.//   

       That is exactly the explanation, and the reason you don’t understand. This question is entirely about summing over time. Your thought experiment deliberately mixes up events and spreads them out over time, to confuse how they all sum up. but the maths is simple, as [MechE] showed. Sum all the impulses over time, sum all the reactions over time, sum all the movement and acceleration of each infinitessimal slice of the ram as the compression wave moves it and moves on, and the answer is F=MA and the ram oscillates back and forth internally with no net movement. Calculus is a powerful tool.   

       See also my Comb design for a simple implementation.
pocmloc, Mar 24 2011

       [Vernon] perhaps we can understand what you're getting at if we start with a point on which we agree and then work forwards from that.   

       So, as a starting point, we have a row of heavy steel masses connected by gentle steel springs (all hanging in mid-air, let's say - we'll do it on the space station). If an astronaut gives the left-most mass a rightward tap, there'll be a slow wave of compression passing through the springs and masses and, after some time, the right-most mass will move.   

       I'm pretty sure that you and everyone else here would agree that this situation is completely explained by conventional Newtonian mechanics; in other words, the behaviour is explicable completely in terms of the elasticity of the springs and the inertia of the masses.   

       Is this correct? i.e. would you accept that, in this "gentle" situation, there is no need to postulate a new type of force? If you disagree, then ignore the rest of this annotation.   

       Now we make the springs stiffer, gradually, in a huge series of experiments. We make them stiffer by making the wire of which they're made fatter, and giving them fewer helical turns. As we do so, we move towards a situation where the "springs" are actually just rods, and these rods get fatter and fatter (to make them stiffer still), until eventually we can no longer distinguish the springs from the masses they connect - we've created a uniform steel rod.   

       Now, according to your argument, this uniform steel rod _will_ experience a strange new force. It doesn't matter if it's very small indeed - it should (according to you) experience _some_ of the strange new force. In other words, Newtonian mechanics is not adequate to explain its behaviour.   

       So, my question is, at what point (as we make the springs stiffer) does Newtonian mechanics fail, and why?
MaxwellBuchanan, Mar 24 2011

       [pocmloc], the math is simple ONLY if there are no side-effects occurring during that overall summation of jerk over time. But according to Stine, such side-effects are indeed possible (snapped cables, repeatable 3-degree phase angle, etc)   

       Here's one we haven't discussed: Originally most auto engines had things called "push rods" to control the opening of the cylinder valves (for fuel-air mix, and for exhaust gas). The push rods were activated by cams that were placed along the engine crankshaft.   

       Nowadays they make relatively few such engines any more. Why? Because of the time it takes for force to propagate along the length of the push rods, there is a maximum RPM at which such engines would work reliably. So they switched to using an "overhead cam" that activates the valves on an up-close-and-personal basis. RPMs have gone up significantly.   

       And for those who want even more, they've been using electric solenoids to open the valves in some engines, replacing the speed-of-sound mechanical-force propagation with a speed-of-light electric-force propagation, for initiating the opening of valves.   

       So, there ARE side-effect consequences associated with the propagation of jerk, that can't be rolled into F=Ma and ignored. But engineers can (and do) redesign things to reduce the propagation time (a.k.a. "Critical Action Time", per Dr. Davis), which THEN lets them ignore jerk!   

       (Recall Stine's "Phaser" gadgets, which pit propagation time against RPM in a way that is claimed to reveal a 3-degree phase angle....)   

       Well, the battering ram features a huge propagation time (relative to ordinary objects) that can't be reduced in my thought-experiment, and so the associated jerk cannot be ignored as a factor in its behavior.   

       That "drop and stop" test I described in an earlier anno here, for measuring breakability of lengths of test-material, combines jerk AND propagation time as factors in the results measured, while the standard pendulum test for fracturing completely ignores propagation time.   

       So far no one here has offered any reason why the propagation time for jerk can be ignored, when some system incorporates a significant magnitude of that propagation time. On March 15, 2011 on the artrr page, I wrote this:   

       "Davis' equations are all about the consequences of jerk propagating through a body. My artrr design does feature that crucial thing --and it seems to me, from studying those equations, that the magnitude of the jerk is less important than the duration of propagation."   

       You people here have done everything you can to not talk about propagation time. But look again at that equation proposed by Davis (but which I simplified slightly for use here) [ F=(M)(a) + (M)(j)(t) ], and it should be obvious that if it has any validity at all, then the greater the propagation time (the longer-length the object through which a jerk propagates), the greater the associated Force.   

       The reason I called the jerk "less important" than the propagation time, even though they are obviously equal factors in the equation, is simply that the propagation time is more easily and precisely controlled than the magnitude of jerk. For example, the drop-and-stop test is, I think, a really simple way to find out if there is some validity there, merely involving different lengths of a test-material.   

       [MaxwellBuchanan], please go to the artrr page and re-read my last annotation of March 14, 2011. I'll now sum up Dr. Davis' work in a pretend-quote, and say "Everything I'm writing about depends on whether or not there is a force proportional to jerk AND propagation time."
Vernon, Mar 24 2011

       //Everything I'm writing about depends on whether or not there is a force proportional to jerk AND propagation time."//   

       Yes yes yes, this I already know, already.   

       The spring system has low jerk and long propagation time, yet has no unexplained forces. It can be smoothly morphed into a solid bar with a high jerk and short propagation time.   

       So, at what point in the "morphing" from sprung masses to continuous bar do these forces pop into existence (however small they may be)? And why can the behaviour of the sprung masses be explained perfectly with Newtonian mechanics?
MaxwellBuchanan, Mar 24 2011

       [MaxwellBuchanan], you wrote: "The spring system has low jerk and long propagation time, yet has no unexplained forces. It can be smoothly morphed into a solid bar with a high jerk and short propagation time."   

       You are morphing it the wrong way!   

       If a relevant equation expression is (M)(j)(t), and (j) is small while (t) is large, and you morph things so that (j) becomes large while (t) becomes small, well, DUH, if the original product was small enough to be insignificant with respect to Newtonian Mechanics, then so will the final product, after the morph, also be small!   

       The basic problem here is that Davis and Stine have made claims that can be tested, but which have not been tested because of people who are sure the claims must be invalid, simply because the claims don't completely agree with Standard Newtonian Mechanics. BAD LOGIC.   

       It's bad logic because of the assumption that SNM is perfect --yet we know it's not, because otherwise we would never have needed to develop Relativity or Quantum Mechanics. The bad logic is that "theory trumps experiment". As a specific example, Stine's "Phaser" gadgets represent a real experiment, but all the denunciations of that experiment come from Theory, and none come from any replication attempts! Tsk, tsk.   

       At least with respect to denunciations of Cold Fusion, there were actual attempts made to replicate the experiments....
Vernon, Mar 24 2011

       OK, you can morph it in whichever direction you like to turn the sprung masses into your device. It really doesn't matter. The point is that SNM (handy abbrevn b.t.w.) takes into account all the terms in the sprung mass system apart from relativistic ones, and relativity accounts for all the terms period.   

       So, if your system isn't fully accounted for by SNM or by relativity, there must (ipso coypu) be a point at which the new phenomenon arises, yet I can't see how there can be such a point in a continuum.   

       But basically you are correct (and I should remember more often) that experiment does trump theory. In this case, that's your downfall, because there are so many situations where this 'strange' effect should manifest itself clearly that the experiment has been done a million times over already.
MaxwellBuchanan, Mar 24 2011

       That's because Pons and Fleischman were reporting unusual results under conditions that were poorly understood, with the chance that something unusual was happening.   

       This is considering results under conditions that are thoroughly understood, with extensive evidence that nothing is happening.   

       I can state that I can get an internal combustion engine with better than carnot effiency, but no one who understands the thermodynamics will believe me. Alternatively, I can claim to have developed an engine that is an extra five percent efficient, but still below carnot efficiency. While this is difficult to believe, it is within the realm of possibility, and thus worth investigating. The first isn't and can be dismissed usng theory.
MechE, Mar 24 2011

       I could claim that if you withdraw all your money from the bank, and give it to me in a brown envelope, then the bank would take pity on you and would refund all the money back into your account no questions asked. However your theory of how the bank behaves, trumps your willingness to perform the experiment.
pocmloc, Mar 24 2011

       [MaxwellBuchanan], my point here is that Stine mentioned a few specific things that could be tested. Just because OTHER things haven't been noticed which could support Stine, that doesn't mean Stine's specific examples can't be replicated. I'll get back to the first part of that in a bit.   

       [MechE], the problem with a better-than-carnot claim, phrased in the way you wrote it, is that it is a mere claim, unaccompanied by a description that could be put to the test by others. It is rather normal to use Accepted Theory to dismiss mere claims that have Zero accompanying data. But at least some of Stine's claims WERE accompanied by testable descriptions, see?   

       [pocmloc], you are neglecting the notion if the theory you posed is true, then you could test it yourself by giving your money to me, heh! What YOU didn't say in your post was whether or not that theory had been tested at all. Meanwhile, I've indicated that I think that the stuff Davis & Stine wrote about makes logical sense to me, so I've been willing to put some money where my mouth was, regarding it, to try to find out if it was true. And I'm willing to do so again, when the circumstances are right, since I'm not satisfied that my previous tests were worthy enough. What I'm saying is that if you pose an untested theory that you are able to put to the test yourself, why should you expect others to test it for you?   

       [MB], Stine indicated that it is common for engineers to come up with something he called "Finagle Factors", to make the normal Newtonian equations fit the experimental observations. When I asked [MechE] about how he would fit jerk into the ordinary equation for force, I half-expected to see something like this: F=(M)(a) + (M)(j)(t)(K), where K is a Finagle Factor that causes the expression it modifies to become very small (irrelevant).   

       Anyway, if such Factors are generally employed by engineers, then that could be the simplest explanation of all why various folks here have said that various observations have been fully explained without needing jerk. But does that automatically also mean using such Factors is the ONLY/BEST way? Davis basically claimed to offer a generic alternative; that is, he and his team of theorists used jerk instead of any/all other Finagle Factors, to explain stuff. Example (paraphrased from Stine's article, to shorten it):   

       "In 1962 the team was joined by Dr. Henri M. Coanda, "father of fluidics", who used Davis' hypothesis to develop a rationale for Reynolds Number and Mach Number." Stine didn't say anything else about that in his ANALOG article, but one way I might interpret what he did say is, perhaps Coanda found ways to derive those numbers from "first principles", instead of from lots of experimental observations.   

       What I'm getting at above is that when I wrote "Just because OTHER things haven't been noticed which could support Stine" --at least some of those other things have various associated and complex explanations that might be simplified by using Davis' hypothesis. Which would then cause those things to actually support Stine's claims, see?   

       Regarding this that you wrote: "there must (ipso coypu) be a point at which the new phenomenon arises", I refer you to my last annotation dated February 5, 2011, on the artrr page, which condenses the "theory of operation", such that if Davis' hypothesis is valid, AND if I've interpreted it into hardware in a valid way, then there absolutely would be a point where the device starts to exhibit "new" behavior. A specific range of such points, actually....
Vernon, Mar 25 2011

       //Non-working Reactionless Drive// Car engine, sitting on breeze blocks, its internal spaces filled with rusty water.
xenzag, Mar 25 2011

       //there absolutely would be a point where the device starts to exhibit "new" behavior. A specific range of such points, actually....//   

       A range of points is....anyway, genug ist genug. I disagree, but have nothing new to say.   

       //Just because OTHER things haven't been noticed...// That's a bit like saying "I've got this theory that painting something stripey will make it explode and smell of lilacs. Just because nobody's noticed stripey things exploding doesn't mean they might not smell very faintly of lilacs."   

       Yes, huge finagle factors (safety margins, factors of safety, call them what you will) are used in engineering to account for variations in material strength, unexpected loads and, certainly, incorrect assumptions and calculations. However, in materials science and many, many other situations, very precise tests and measurements are made. I really believe you need to be aware of the variety and accuracy of measurements which have been made already.   

       At the very least, you need (to avoid you wasting your money) to understand the theory behind your "ATRR" well enough to be able to calculate how much reactionless force _should_ be produced in various everyday situations.   

       If those predicted forces turn out to be indetectably small, then you still have a case. If (as I suspect) they turn out to be so huge that they would certainly have been noticed already, then you can save yourself a lot of time and effort.   

       In other words, at least in the privacy of your own cell, you should be trying to disprove reactionless drives by seeking out the enormous wealth of prior experimental evidence, rather than trying to convince yourself that it will work. If you fail to disprove it in this way, then you should go ahead.   

       That's how it works, and is why science is generally fairly efficient: you don't bother painting the stripes on if you can use other people's data to show that zebras don't explode or smell of lilacs.
MaxwellBuchanan, Mar 25 2011

       If you were to interlace two zebras together, would they cancel eachother out?
RayfordSteele, Mar 25 2011

       Every two pies, they would cancel. But every other pie, they would reinforce. And so you would be able to see alternately dark and bright zebras.   

       And that proves the wave-particle duality of zebras.
neelandan, Mar 25 2011

       {MaxwellBuchanan], I face a different problem than what you have described. You have made the assumption that I am ABLE to do such disproving. Sorry, can't afford access to the technical journals holding the data. And don't know calculus well enough. But I'm able to do this experiment, and I suspect it would cost (to me) about the same as accessing the journals, so....
Vernon, Mar 25 2011

       You could let people who do understand calculus and engineering science do the disproving for you. They could show you equations containing the terms you have defined. You could believe them.
pocmloc, Mar 25 2011

       You could *learn* calculus in less time than you spend glorying in your ignorance thereof.   

       If you'd spend some time learning what *is*, your subsequent excursions into *might be* would be of much higher quality.   

       [Oh, and about access to journals: if you find an article that would help you, but can't get to it, shoot me an email. I have access through a uni, which lets me into a substantial amount of stuff. Research purposes, all that - it's proper use of resources.]
lurch, Mar 25 2011

       Actually I've heard claims in these annos that they've calculated Planck's Constant and other stuff, using a different form of math than the standard. You'd think that would *really* interest people. It interests me and I don't even know what Planck's Constant is.   

       So [V], far be it from me to dissuade any experimentation, but why don't you simply bundle up a copy of the prooves and shoot them off to the local university; see what kind of mark they get; shouldn't cost you more than a couple beers or whatever the local equivalent currency is.
FlyingToaster, Mar 25 2011

       "proofs" is too unaesthetic... "provings" perhaps ,or the more colloquial "provin's".
FlyingToaster, Mar 25 2011

       It also looks like a kludge.   

       hoof, hooves
roof, rooves
behoof, behooves

       proof, prooves (proves).   

       ... your moof.
FlyingToaster, Mar 25 2011

       mouse, mice
house, hice
louse, lice.
pocmloc, Mar 25 2011

       ... from the old French "preuve" or Latin "proba"... where do you see an "f" in that to begin with ?   

       Okay, here's your leg back, but I really do object to adjacent voiceless fricatives.
FlyingToaster, Mar 25 2011

       What about the respective starts of a sequence of footbal games - the kick-oves?
pocmloc, Mar 25 2011

       [pocmloc], if such experts as you describe would bother to actually perform DIRECTLY relevant tests (such as the drop-and-stop test described in an earlier anno here), instead of assuming that various things already tested are perfectly relevant, then, yes, that would be a good reason to believe them.   

       [lurch], no, I already tried learning calculus, and it didn't take. SOME of it I think I can do (mostly of the differential type, since it is mostly algebra), but the integration stuff leaves me mentally blank.   

       Next, the HalfBakery for what "might be". Why do I want to become just like the ancient "experts" who were sure that fire was too dangerous to bother to harness?   

       Regarding the offer to look up journal articles, thank you, but there are other things I want to do more, than spend so many hours searching the literature that if I did something else instead, I could probably earn enough to build 3 artrr experiments, before I found something proving the gadget can never work.   

       Finally, I work as a mechanic, so while I don't know a lot about how mechanical engineers go about designing stuff, I know what it's like to work on the result: Often it's a nightmare, like when there are cascade failures, instead of fail-safe. It does NOT give me confidence that they know enough about what they do, to believe them when they say that something is so!
Vernon, Mar 26 2011

       Vernon, the problem with your last statement is that it assumes all mechanical engineers are the same. Some of us are not the brightest, some are geniuses, and most are somewhere in the middle.   

       While it's perfectly acceptable to think the idiots missed something, and maybe even those of us in the middle, you're also assuming that every single one of the geniuses did as well. That's asking a little much.
MechE, Mar 26 2011

       [MechE], in Physics there are generally considered to be two sorts of physicists, the theorists and the experimenters. Very few people have proved to be excellent in both categories. (You should look up the tales about P.A.M. Dirac, who they say was such a good theorist that he had to be banned from labs, just because if he walked by the door, the experiment in progress would fail, heh!)   

       If such a distinction is normal in other fields, but mechanical engineers are as a class oriented more towards nuts-and-bolts than theory, well, sure, the geniuses in the field would design wonderful stuff. Without, however, necessarily worrying too much about why this or that aspect of it had to be Finagle-Factored.
Vernon, Mar 26 2011

       Except that every single mechanical engineer and scientist for the past 300 years has gotten the same results. Whether doing pure research or design, the equations work. Whether doing simple work or rocket science, the equations work.   

       I don't know if you actually noticed my screen name, but I know what the fudge factors are. They're common in some fields because the math in those fields is extremely complicated. They show up a fair amount in fluid dynamics, because turbulent flow is nasty like that. There are some approximations that show up in thermal work, because it simplifies the math.   

       Simple dynamics and ballistics, about the only simplifying assumption involved is neglecting relativistic affects, and I can figure those in if you want. Likewise structural work and materials, which figure into what you're talking about. The math works, it accurately describes mechanical systems.
MechE, Mar 26 2011

       [MechE], yes, I guessed what your handle represented. But you are still possibly wrong in what you wrote last, simply because if it was completely true, then why did Stine's cables break when the math said they were strong enough? And where did the 3-degree phase angle come from in his two different "phaser" gadgets?
Vernon, Mar 27 2011

       This has gotten so big, my browser crashes when trying to load the whole thing.   

       I have to read it via google translate set to show the original - not sure how that works, though.   

       Stine was horribly bad at maths as well as physics, so his cables broke because he couldn't calculate.   

       The 3 deg phase angle was pulled out of his ass.
neelandan, Mar 27 2011

       sp. arse
pocmloc, Mar 27 2011

       So the Gravitational Constant is actually Gravitational Incontinence ?
FlyingToaster, Mar 27 2011

       And again [neelandan] don't know what they are talking about. I quote from Stine's article: "All calculations by the stress group proved that the cables and booms were more than strong enough to absorb the expected loads" --Stine wasn't the one doing the math!   

       Also (paraphrasing to reduce length): "The May 1963 ANALOG had a letter from Dean that gave explicit instructions on how to construct an experiment regarding "phase angles". This device happened to be identical to my Phaser Mark I. So, I dug it out and had our two best lab technicians read Dean’s letter, set up the device, and run the test. They conducted these tests without any supervision from Davis, Victory, or myself; we just watched. Dean claimed they could see a 45-degree phase angle. They saw the 3-degree phase angle that I had seen."   

       But since various folks here seem to think that Theory (which doesn't even allow a 3-degree phase angle) Trumps Experiment, therefore the above just has to somehow be erroneous, right? PROVE IT!
Vernon, Mar 27 2011

       The Comet airliners kept failing catastrophically due to reactionless drive, until someone figured it was metal fatigue. Likewise, the Tacoma Narrows bridge failed due to reactionless drive, until someone included resonance in the analysis. Bent spaghetti used to snap in two places instead of one, due to reactionless drive, until someone looked at shockwave propagation. Heck, millions of structures have failed due to reactionless drive, until some killjoy figures out the real reason. Darn those killjoys.   

       On the topic of experiment trumping theory, I am unaccustomedly in agreement with [Vernon]. However, here we (or [Vernon]) are hoping for experiment to trump a deep river of theory which has been built on the back of...<can one build a river on the back of something? no matter>...on the back of an almost infinite number of intentional and natural experiments. And, since [Vernon] admits that his only experimental attempts to date have failed, this idea remains theory rather than experiment itself.   

       Yes, experiment does trump theory. But science moves fast because it uses theory to set a threshold of credibility, so that it doesn't waste its time on experiments that are very unlikely to work. It counts on whackos to rummage around the detritus of highly- implausible experiments, since their time is less valuable (and there are more of them), and since once in a blue moon they do come up with something.   

       That's how the game works. You can't win the game by arguing, because people have already done the theoretical stuff when they threw this idea out on the detritus pile. You can only win by building and doing in a convincing way.   

       It's like picking over the tailings from a gold mine. The guys who work in the mine know with near-certainty that they didn't leave any big nuggets in the tailings. You might get lucky and find a huge nugget that they (and all the other pickers) have missed, but the odds are low and they're pretty sure it's not there to find. Meanwhile, the professional miners know they're better off mining a productive seam, or prospecting elsewhere, than picking over the tailings
MaxwellBuchanan, Mar 27 2011

       //Sorry, can't afford access to the technical journals holding the data. And don't know calculus well enough.//
Sorry, [Vernon], but ignorance is never an excuse.
If you build and try to sell some gizmo with doing a patent search (can't afford it, didn't know...), only for the owner of a patent for a similar gizmo to sue you, the judge won't allow ignorance as an excuse either.
If you want to do deep physics that involves complex maths, you kind of need to be able to do the complex maths, otherwise you're wasting your time.
neutrinos_shadow, Mar 27 2011

       Experiment does trump theory. There have been thousands of experiments (real world tests) that prove you are wrong, and all you have is the theory that says you are right.   

       Which wins?
MechE, Mar 27 2011

       //PROVE IT!//   

       Stine et al already proved it, right? Like Hahnemann proved homeopathy.
neelandan, Mar 27 2011

       //Meanwhile, the professional miners know they're better off mining a productive seam, or prospecting elsewhere, than picking over the tailings//   

       Oh for Pete's sake, thars gold in them thar tailings!   

       //If you want to do deep physics that involves complex maths, you kind of need to be able to do the complex maths, otherwise you're wasting your time.//   

       Yeah, like daydreaming about what it would be like to ride on a beam of light took right? Or why the apple fell?   

       I'd say that the math tries to keep pace with the dreaming and not the other way around.   

       [MaxwellBuchanan], lies do not become you. There were no preconceived notions involving jerk in the examples you cited. There WAS such a notion in the ejection-system failures that Stine encountered, because Stine specifically talks about "rate on onset" of the forces that the broken parts experienced, and how they reduced that by allowing a greater rate-of-onset to reach the humans who would occupy those ejection systems.   

       Next, if you are willing to admit that "once in a blue moon they do come up with something", then you should also accept the idea that when they do, their claims need to be replicated/tested, not disposed of by invoking Theory. So, why shouldn't Stine's claims be replicated/tested? How ELSE might you be sure whether or not he (and Davis and Dean and...) actually came up with something worthwhile? (You left that part out of your post!)   

       [neutrinos_shadow], exactly what am I using ignorance as an excuse for? If it costs $X to access lots of journals to find out lots of relevant data, that MIGHT prove the gadget can't work, but also costs about the same to actually build the thing and MAYBE find out it can work, what makes one choice better than the other? And, if I couldn't grasp integral calculus before, to be able to use it when needed, why should you expect me to suddenly be able to grasp it now, to be able to use it here? Have they somehow improved how that subject is taught? I wish!   

       [MechE], in what way do Stine's broken cables and Phaser gadgets count as "theory"???   

       [neelandan], you still aren't making sense. If Stine & Co proved anything, it was that it can be really difficult to get people, whose minds are made up on a subject, to look at data supporting a different point of view. A thing that has been proved over and over again by others. I think I'll add a link to a more recent example (a video in which one person, among other things, talks about asking someone to look at some data).
Vernon, Mar 28 2011

       The fact the cables broke doesn't count as theory, his thoughts on why they broke do.   

       If I try to lift a 20 pound weight with 30 pound test line, it will lift. If I try to accelerate it upward at .5g, it will lift (1.5g total, 30 lbs). If I try to accelerate it up at .6g, it will break (1.6g total, 32 lbs).   

       If I accelerate it upwards at an average of .5g, but allow my acceleration to vary between .4 and .6g, it will break even though the average says it won't. I see nothing in any of the literature where this fails to explain the broken cable results without bringing in an unknown theory with no other evidence to support it's existence.
MechE, Mar 28 2011

       //jerk in the examples you cited// no, of course not. But they were equally "inexplicable" mechanical failures until someone took the trouble to explain them. Likewise Stines snapped cables.   

       //So, why shouldn't Stine's claims be replicated/tested?// Of course the should! However, because 'incidental' experiments have failed to replicate the results, and because the results seem so unlikely to be remotely plausible, my point was that nobody in their right mind is going to waste their time doing so. People have other things to work on, which seem more likely to work in the light of our understanding of the universe. But, as I also pointed out, the serious people will be quite happy for whackos to try this - nothing lost for us, and no harm done. If you find the nugget in the tailings, well, hey, that's a surprise and good for you (and physics). If not, hey, your loss not ours.   

       So, go for it, and you just have to accept that you'll get a lot of ridicule. Of course, that makes it all the more satisfying if it works. If everyone said "Yeah, of course it'll work, it's obvious." would you be as passionate about it? No.   

       Finally, a question. Since you're so convinced that "conventional wisdom" and "the scientific system" is foolishly neglecting this revolutionary discovery, why are you so keen to persuade us of the error of our ways and having this accepted by "the system"?   

       Why are we worth convincing?
MaxwellBuchanan, Mar 28 2011

       For the record, no one has denied that forces propagate through materials, and that this cannot produce interesting results. In your initial ram example, the material is much more likely to fail because the compression waves from the end force cross the compression waves from the continous force, producing extreme compression, where ignoring propagation, the two waves never encounter each other. This might produce failure where it is not expected, but it doesn't require any unusual math to explain it.
MechE, Mar 28 2011

       [MechE], Stine wasn't talking about mundane examples such as what you wrote about. Remember it was the extremes that led physicists to realize that Standard Newtonian Mechanics was inadequate in at least two areas (the extremely small and the extremely fast). The ejection system he worked on weighed how much, and the cables were rated for how much? I'd guess closer to a "tons" than to a mere 30lbs. Relatively extreme, see?   

       So, when Stine wrote that all the calcs said the cables were more than strong enough, I have no reason to think he wasn't talking about the forces associated with the relatively large acceleration of the ejected mass, in the same way that you wrote about. But since the cables broke, anyway (and apparently always, until they modified the system to absorb less jerk), that left him with a Mystery.   

       You may think that they overlooked some mundane explanation for that mystery. But think about how long it must have taken his group to get the Air Force to relax the specifications regarding application of jerk to the human body (modify the contract specifications!) --why wouldn't the math group have been seeking all sorts of possible explanations during that time? If the math group had succeeded, then Stine might not have thought it relevant to Dr. Davis' line of research....   

       [MaxwellBuchanan], think of this as practice-arguing. Even if an artrr actually works, there will be those who would refuse to look at the data....
Vernon, Mar 28 2011

       You know what the difference between 30lbs and 30 tons is from a design standpoint?   

       Neither do I. There isn't one. Rewrite my example with 30 ton test cable, it makes no difference.   

       I acknowledge there is some difference if the relative contact speed between two materials is greater than the speed of sound in the materials, but only that.
MechE, Mar 28 2011

       From what I gather, "jerk" is the sudden acceleration at the beginning of a movement precipitated by an outside force. In the case of a sledgehammer hitting a spike, the contact area is under tremendous G-force until the rest of the spike catches up, thus the loud bang, sparks and local heating. Of course what this has to do with antigravity is beyond me.
FlyingToaster, Mar 28 2011

       [2 fries shy of a happy meal], this reactionless drive stuff has gone beyond daydreaming, and people are trying to Do Stuff. This requires thinking, not dreaming. Those guys could do (in fact created) complicated mathematics.
1: By 'ignorance', I mean you know that there is useful data out there that pertains to what you are doing, but you are ignoring it (whether by financial incapacity or whatever). Standing on the shoulders of giants, and all that...
2: I didn't imply that you 'suddenly' needed to grasp calculus for other halfbakers sake. You are the one doing the reactionless experiments, and by your own admission (IIRC) things need to be precisely calculated. Therefore, you need to be able to do the precise calculations, for your own sake. Forget about the rest of us.
For example, if I didn't know about decimals or fractions, and a calculation required 16/7, I would give the answer as 2. But if this is not accurate enough for the precision I was wanting, I'm stuck. Only after I understand decimals and division, do I get the more accurate answer of 2.285714... This is what I was meaning.
neutrinos_shadow, Mar 28 2011

       [FT] Jerk is the rate of change in acceleration, just like acceleration is the rate of change in velocity, and velocity is the rate of change in position.   

       [Vernon]'s claim is that something happens when that hammer hits the spike to cause some of the energy to go elsewhere.
MechE, Mar 28 2011

       Ah, I see... there's even a WP article on it. Don't mind me though: I can't even figure out why the velocity is squared in KE=1/2mv2.
FlyingToaster, Mar 28 2011

       [MechE], how many times to I have to repeat that it is stuff that STINE and others claimed, that I have described here, and that those are not my own claims? Stine is the one who basically said that the standard calculations (now I quote you: "from a design standpoint") FAILED to be accurate when large loads and jerks were involved.   

       Either his claim is true or it isn't. But it should be fairly simple to test.   

       [neutrinos shadow], for the proposed artrr I actually don't need precise calculations. All I need is two different response times --the (t) in the equation-expression (M)(j)(t). Because if that expression really deserves to be attached to the standard F=(M)(a), then different values of (t) should practically guarantee different behaviors with respect to applied forces. Very simple.   

       Meanwhile, I've noted elsewhere above how mechanical engineers have worked to minimize (t) wherever possible (and how they specially can ignore it in their standard pendulum/fracture test. This implies that there will actually be relatively little relevant data in the literature (could be so much harder to find that it remains simpler just to build an artrr).
Vernon, Mar 28 2011

       //I have to read it via google translate set to show the original - not sure how that works, though.//   

       I think some sort of caching proxy server was sitting in between, and it had cached a partial copy of the page. No matter how I tried, trying to refresh the page, it served the partial saved copy.   

       Loading it via google translate bypassed this copy (or forced it to load a fresh one) and I could see the complete page, again.   

       However, this page and the artrr page causes my phone to display a sad "out of memory" error message.   

       None of which relates in any way to reactionless drive, working or not, but does highlight the fact that the discussion drags on and on and on and arrives nowhere.
neelandan, Mar 28 2011


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