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skydive

A thrill of up
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I would bring my arms together, hands interlinked above my head.I'd take a breath, relax. Finally, make my body ridgid and ignite.

W = m(kg) .g(N/Kg).h(m) = 72+0.7 x9.8 x4000 = 2849.84(KNm) = 2849.84 KJ

TNT 4600 KJ/Kg x 0.7Kg = 3220 KJ/Kg 2849.84 / 3220 +12%

With the TNT packed, shaped and grained correctly, my dive boots will travel. I just have to remember to strap on my floaty wing.

wjt, Apr 30 2012

The terrestrial version Dirt_20Surfing
[doctorremulac3, May 06 2012]

You're going to need this http://www.scientif...al-males-eat-yogurt
Bon courage, mon ami... [lurch, May 10 2012]

[link]






       We will pay a dollar, cash money, to watch this.   

       Just tell us where and when.   

       [+]
8th of 7, Apr 30 2012
  

       //my dive boots will travel// Indeed they will, as surely will your feet. Your legs stand a fair chance of travelling too; your torso less so.
MaxwellBuchanan, Apr 30 2012
  

       Sorry, I have not reached the age I would test this.
wjt, Apr 30 2012
  

       Doesn't success depend on how well controlled the TNT burns and the acceleration curve produced?
wjt, Apr 30 2012
  

       between atmospheric drag and off-vector losses you'll need much more than 0.7kg to get up 4km.
FlyingToaster, Apr 30 2012
  

       Anything above 800m is just bonus
wjt, Apr 30 2012
  

       // how well controlled the TNT burns //   

       TNT, like its analogous crystalline ppolynitrated aromatics, does not "burn"; it detonates, which is a physically and chemically different process.   

       // and the acceleration curve produced?//   

       Since the detonation will be supersonic, the Munroe effect may be relevant (q.v.). Acceleration of the test subject is guaranteed; the problem being that individual components of said test subject will accelerate at noticeably different rates.   

       // between atmospheric drag and off-vector losses you'll need much more than 0.7kg to get up 4km //   

       We disagree, presuming that the idea relies on post-initiation convection of the gas bubble to convect at least some of the test subject (hereinafter rreferred to as the "pink mist") to a relatively high altitude.
8th of 7, Apr 30 2012
  

       Putting aside the mechanism, isn't this just a question of scale and control? The correct amount of TNT to create the correct detonation blast bubble that applies the needed force. Given the right timing sequence of bubbles I would be lifted to on high without loss of bodily integrity. Of course, a chamber/wall of sorts in the dive boots would be needed. The total 0.7 kg would be converted into successive varying pulses of detonation.
wjt, May 06 2012
  

       //I just have to remember to strap on my floaty wing.//   

       And fill out your will. Only a madman would come up with the idea of riding waves caused by explosions for sport. (See link)
doctorremulac3, May 06 2012
  

       Strange, I read that as "floaty wig", and I thought that was brilliant. "Floaty wing" sorta sinks for me.
blissmiss, May 06 2012
  

       If you've a "floaty wing" (or a well-attached floaty wig, for that matter) what do you need TNT for ?
FlyingToaster, May 06 2012
  

       // Putting aside the mechanism, isn't this just a question of scale and control? //   

       No, it isn't. You are either unaware of, or deliberately disregarding, a number of very important factors. Go and read up on the highly significant difference between a propellant and an explosive.   

       // The correct amount of TNT to create the correct detonation blast bubble that applies the needed force. //   

       It's not just about force- it's about impulse, which is a force/time quantity.   

       // Given the right timing sequence of bubbles I would be lifted to on high without loss of bodily integrity. //   

       … apart from the intrinsic supersonic shock waves reducing you to a smooth, jelly-like consistency by hydrostatic rupture of your cell membranes.   

       // Of course, a chamber/wall of sorts in the dive boots would be needed //   

       Something a bit more resilient than Odour- Eaters, certainly.   

       // The total 0.7 kg would be converted into successive varying pulses of detonation //   

       "Detonation"… oh, that word, how it haunts us…   

       PLEASE tell us when you are going to demonstrate this idea…
8th of 7, May 06 2012
  

       A detonation shock wave has a finite radius. At some point the wave is deflectable and the ensuing blast rideable. How tiny would the amount of TNT be to shake a the gap between heavy steel plates?
wjt, May 08 2012
  

       You don't need TNT for that; a basic propellant would suffice. You tell me the dimensions of the plates and I'll work out the transfer properties. How painful would be the broken ankles of the one standing on the plates, expecting to be launched into the air?
Alterother, May 08 2012
  

       King David's Spaceship.   

       other than that I'm going to burn your science teacher in effigy.
FlyingToaster, May 08 2012
  

       500x500x10mm - gapped to 0.2 of a mm peak raise. More than one amount can be used.   

       This is what collective humanity does. Imagines big and then use lots of tests, technology and time to achieve some that is thought to be impossible. Everything starts with small steps.
wjt, May 10 2012
  

       The density of steel is about 8 ... given the spec'd size of your plates, you're adding at least 20Kg to the total mass of the system. That's without the "ski-boots", clamps, some sort of shock absorber, the initiating/timing mechanism and power supply, plus the mass of your parachute - which is presumably harnessed to your back, and therefore an additional load on your lower limbs. Basing the figures on the US T-11 chute system, which weights 25Kg (including the reserve), and allowing another 10 Kg for the gadgetry, plus a helmet, that's a total of 55Kg over and above the mass of the victim, sorry, tester.   

       The parachute is going to significantly alter your centre of gravity, but if you're wearing the parachute anyway, might as well make use of the harness. Stand on a single plate (titanium probably better than steel) with a rod or loop that sticks up from the plate and has a strap down to the back of the harness.   

       Sure, you'll end up singing soprano for a while, but it would mean that the chances of dying immediately the system launched would be diminished ... but only very slightly.
8th of 7, May 10 2012
  

       The scream would probably be quite something, too. Definitely a situation for an open-face helmet, if only for the enjoyment of the spectators (and to boost sales of the DVD).
8th of 7, May 10 2012
  

       What's the calculated impulse of one molecule/complex of TNT ? Ultra fine movement measurements of the steel plates might act as testbed for raw data. The more power the less you need, right ?   

       My thoughts were more along the lines of infinitesimally fine control of a detonation explosive. Rather than one super large impulse, a burn of impulse. Maybe, a titanium stick containing layered microscopic explosive capsules so as the explosive shock wave fractures the titanium more explosive is exposed and set off.   

       I agree that the initial set off would be a problem, no real soft fluid space for the full brunt of shock wave to dissipate. Maybe a trebuchet.
wjt, May 13 2012
  

       // My thoughts were more along the lines of infinitesimally fine control of a detonation explosive. Rather than one super large impulse, a burn of impulse. Maybe, a titanium stick containing layered microscopic explosive capsules so as the explosive shock wave fractures the titanium more explosive is exposed and set off. //   

       Don't make us come over there. Please, try to understand before we throttle you ...   

       What you are describing is exactly the behaviour of a propellant.   

       "Burning" and "detonation" are totally different.   

       Detonation implies supersonic propagation of the event front; if it's slowed down as you suggest, (a) it's not detonation, and (b) secondary explosives such as TNT will NOT initiate.   

       What part of "No" don't you understand ?   

       // Maybe a trebuchet. //   

       Now, that's a MUCH better idea ...
8th of 7, May 13 2012
  

       // (titanium probably better than steel) //   

       Titanium can be manipulated to obtain all sorts of properties, but it can't be tempered quite as far as steel; the risk of fracture under shock impact is higher.   

       Also, only 10mm of steel, especially with a 500mm square plate, courts a high degree of deformation, absorbing much of the energy you want to transfer for your launch. Remember, the wider the plate, the more deformation. I would go with at lest 25mm for your top plate, significantly more for the base.
Alterother, May 13 2012
  
      
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