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# Dark Charge

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So, I was wondering about dark energy and dark matter. If you know about such things, skip the next two paragraphs or, better yet, the entire idea.

Dark matter: it seems that galaxies are spinning around too fast to be held together by their own gravity. Therefore, we have to postulate some additional, invisible mass (dark matter) to provide the gravitational glue to hold all the stars together in a galaxy.

Dark energy: the universe is expanding (post big bang) but, oddly, the rate of expansion is increasing. This is the opposite of what you'd expect: gravity should be pulling everything back and slowing the expansion. Hence 'dark energy' as a mysterious provider of force to account for the accelerating expansion.

Hmmm. Here is a stupid alternative suggestion.

Suppose that the cores of galaxies tended to be positively charged overall, whilst their outer regions were negatively charged. This might happen (in my simple world view) because, whenever protons and electrons find themselves alone in interstellar space, the heavier protons are gravitationally pulled gently towards the galactic core, whereas the much lighter electrons are much less pulled. It might also happen because radiation pressure will tend to drive isolated electrons away from the galactic core to a greater extent than it drives the heavier protons away.

You might, therefore, have galaxies with positively charged cores and negatively charged peripheries.

At the centre of such a galaxy, the density of matter would be enough to hold things together against their electrostatic repulsion. At the periphery, electrostatic attraction would keep the negatively charged outer stars bound to the positive inner core. Remember that electrostatic forces are about 10^34 times stronger than gravitational ones, so a small charge difference would make a big contribution. Gadulka! No need for dark matter.

Now to dark energy. Atoms in a solid repel one another because, although each atom is neutral overall, the negative outer shells of the atoms prevent them getting too close. In effect, each atom only "sees" the outer layer of electrons of its neighbours.

If all the galaxies have negative "shells" around positive cores, then there will be a net repulsion between galaxies and, gadulka! No need for dark energy.

It's also been noted recently that more galaxies spin one way than the other, in the universe. I'm sure there's some sort of alignment-of-dipoles argument to be had here.

 — MaxwellBuchanan, Nov 13 2012

Question: Why isn't this an explanation for "Dark Matter"? http://www.bbc.co.u...nvironment-13416431
I may be showing my ignorance on this one - but, if they've counted all the stuff that emits light, but their calculations don't come up with the answer they'd expect - how about including all the things (like what's in the link) that they can't see? Presumably, that's an oversimplification - but can someone explain why that's an oversimplification? [zen_tom, Nov 14 2012]

No-hair theorem http://en.wikipedia...iki/No-hair_theorem
Black holes have mass, charge and angular momentum ... and that's it. [Wrongfellow, Nov 14 2012]

Kata/Ana viseo games Kata_2fAna_20Alter-Dimension_20Games
Speculation herein about the behaviors of extraplanar objects of all sorts. [bungston, Nov 14 2012]

 Hmm. I'm not sure I'm on board with this idea of free-floating electrons and protons. It seems to me that they would tend to find each other within their localized area of space, thus canceling each other out pretty quickly. As you said, the attracting force between protons and electrons is far stronger than gravity, indicating that isolated electrons and protons would be attracted to each other despite gravitational pull.

 //Remember that electrostatic forces are about 10^34 times stronger than gravitational ones, so a small charge difference would make a big contribution.//

 Given the tremendous mass of a galaxy, you'd still need a LOT of isolated protons and electrons to overcome the force of gravity.

But then again, I do like the fractal nature of this theory, so I'm inclined to award a bun for sheer elegance.
 — ytk, Nov 13 2012

Do the electrostatic forces work over that great a distance? It was my understanding that gravity is the farthest-acting force even though it is the weakest. Then again I learned that at an American high school so it is probably wrong.
 — DIYMatt, Nov 13 2012

 //Do the electrostatic forces work over that great a distance?//

 Yes, both gravity and electric forces fall off as the inverse square of the distance.

In the case of galaxies with negative "shells" and positive "cores", the net repulsive effect will fall off more quickly. Basically, when two such galaxies are far apart, the negative "shell" of one is only a little bit closer (proportionally) to the negative shell of the other than it is to the positive core. But there's still an effect.
 — MaxwellBuchanan, Nov 13 2012

I think it's time to invent my *string theory bikini*.
 — xandram, Nov 13 2012

Next time eat about 1/3 less brownie.
 — WcW, Nov 13 2012

But don't most galaxies have a black hole at their core? If this is the case then in your model it would be a black hole made from protons and I'm not sure electrostatic forces would be able to escape from it. The current induced by gazillions of protons orbiting the black hole at near light speed as they spiral down to their demise would be impressive though.
 — hippo, Nov 13 2012

 // The current induced by gazillions of protons orbiting the black hole at near light speed as they spiral down to their demise would be impressive though. //

Correction, there would be a large magnetic field, not a current.
 — scad mientist, Nov 13 2012

 I don't buy your reason for neutrally charge galaxies repelling each other. Electrostatic force can be calculated like gravitational force. If there is a sphere (or shell) of negative charge, the force can be calculated as if the charge is concentrated at a point at the center. A similar calculation can be done with positive charge. If the total charge is the same and the center is the same, then there will be no attraction to a charged particle (or galaxy) at a distance.

I would assume (possibly incorrectly) that on an atomic scale, neutral atoms wouldn't attract or repel each other until they were within the distance of their outer electron shells. As soon as the shells overlap at all, you can no longer treat the charge as a single point, and the positively charged nuclei will repel each other. Of course that doesn't take into account the discrete nature of electrons and any quantum mechanic effects. Can you reference some info about atomic repulsion due to the atoms only "seeing" the outer electron layer?
 — scad mientist, Nov 13 2012

 //I would assume (possibly incorrectly) that on an atomic scale, neutral atoms wouldn't attract or repel each other until they were within the distance of their outer electron shells.//

 I'm not sure, but I think you're wrong. On the other hand, you might be right.

 I don't have a specific reference for atoms only "seeing" eachother's electron shells - it's one of those things I think I've always known, without knowing how I know it.

 //But don't most galaxies have a black hole at their core?// Maybe. I'm not sure what happens to charge if a black hole swallows more protons than electrons. Can a black hole have a charge?

 // there would be a large magnetic field// Do we know how big a field? In particular, do we know how much charge (in coulombs per cubic parsec or whatever) would be needed to hold stars together in a spiral galaxy? My guess is that the charge *density* would be fantastically low.

And do we know that galaxies don't have hefty magnetic fields associated with them? Maybe they do, and maybe that's why they seem to have a preferred (aligned) spin.
 — MaxwellBuchanan, Nov 13 2012

 //Can a black hole have a charge?//

I suspect not, because if it did, that would indicate the relative number of protons and electrons in it. Since information can't escape from a black hole (according to last year's scientific thinking, at least), it would seem to be impossible for it to have a charge—at least, one that's determined by the matter it has swallowed up.
 — ytk, Nov 13 2012

OK, so if I make a little ion gun, and use it to fire positive ions into a black hole, while I fire the electrons the other way, then space gains a negative charge but the black hole doesn't gain a positive charge?
 — MaxwellBuchanan, Nov 13 2012

Well, if we are doing theories, my own view is that we don't need any of this scientific complication. Simple half-baked logic will serve just as well. If we live in an infinite universe which seems to be expanding (which, in my book*, rather calls into doubt our concept of what infinity is) then it seems likely that it must be expanding into something. That something must, ipso facto, be bigger than infinity. It therefore stands to reason that the gravitional forces existing in something that is bigger than infinity must be able to overcome those existing in something that is only infinite in size and hence our paltry, infinite universe is forced to expand by the overwhelming attraction of the greater than inifinite gravity without...or beyond...or whatever it is out there.

*My book is 'The Princess Bride' and I don't think that that word means what you think it means.
 — DrBob, Nov 13 2012

 //OK, so if I make a little ion gun, and use it to fire positive ions into a black hole, while I fire the electrons the other way, then space gains a negative charge but the black hole doesn't gain a positive charge?//

I don't know. Is that a problem?
 — ytk, Nov 13 2012

 //Can a black hole have a charge?//

 Yes, it can.

We refer you to Prof. S. Hawking, where knowledge may be had.
 — 8th of 7, Nov 13 2012

//Is that a problem?// I don't know. It just seems odd that you could create a net negative charge in the universe by hiding all the protons in a black hole.
 — MaxwellBuchanan, Nov 13 2012

 //do we know how much charge (in coulombs per cubic parsec or whatever) would be needed to hold stars together in a galaxy?//

 That's a damned good and insightful question. Let's see.

 OK, we could start by asking what electric charge would be needed to create an electrostatic force between two stars which is (say) tenfold greater than the gravitational force between them.

 The electrostatic force is roughly 10^39 times greater than the gravitational force (if we're thinking about proton-proton forces as a simple case). Ergo, there would need to be one surplus electron per 10^38 hydrogen atoms.

 A sun-sized star contains about 10^57 hydrogen atoms, so we'd need a charge of about 10^19 electrons. That's only a Coulomb of charge, or equivalent to charging a biggish but commonplace capacitor up to 1 volt.

Hang on a tick. That doesn't sound right. Where'd I go wrong?
 — MaxwellBuchanan, Nov 13 2012

I thought that was one of those trains that goes up the side of a mountain?
 — MaxwellBuchanan, Nov 13 2012

 //Where'd I go wrong?//

 I'm not sure your calculations are wrong, as such. I think your error might be in treating a gravitational mass as physically similar to an electrostatic charge. I just don't think it's all that easy to maintain a surplus of that many electrons in one place for long enough for them to have a substantial effect before dissipating.

I'm not sure why I think that, though—that's just my gut reaction. My formal physics education amounts to roughly nil, however, so take it for what it's worth.
 — ytk, Nov 13 2012

And the idea is?.... A yo-yo Galaxy on a string of course!
 — xenzag, Nov 13 2012

// OK, so if I make a little ion gun, and use it to fire positive ions into a black hole, while I fire the electrons the other way, then space gains a negative charge but the black hole doesn't gain a positive charge? // This looks very similar as the electron holes in semiconductors.
 — piluso, Nov 14 2012

I really don't know where to start criticizing this idea, so I won't.
 — sqeaketh the wheel, Nov 14 2012

 I've never really understood how the space between galaxies can be stretching, while the space within an atom -- or for that matter (pun intended) within a solar system, isn't. Does that mean that gravity is necessary to hold not just matter, but space/time together?

In that scenario, the classic illustration of a gravity well -- the orbiting marble depressing the fabric of space/time -- is incorrect and certainly somehow counter-intuitive -- space/time is not in fact stretched in the presence of gravity -- it's stretched in its absence.
 — theircompetitor, Nov 14 2012

//Can a black hole have a charge?// - see link.
 — Wrongfellow, Nov 14 2012

 First a kick to the theory: it is proposed that mass is adequate to separate charged particles (protons in, electrons out). Then that charge different is adequate to move universe bits about. It seems to me that formidable charge puissance would just keep proton and electron together in the first place. Yah, ytk said that.

 A testament to Max's gravitas that this party has not been banished to Overbaked for being theory. So I will sidle up to the keg! I am still fond of my extraplanar explanation for dark matter, which I rambled about in the linked Kata/Ana idea; the most relevant paragraph I will paste below. If you are going to posit matter with weird properties, the property of being extraplanar is not that weird.

 harks back to a discussion elsewhere about "dark matter/

 I was getting excited about thinking about this today. Imagine not some funky 4D sphere but normal 3D objects, each in their own 3D planes. OK, for illustration instead consider a series of flatland planes stacked like shelves. Objects on different planes at some 2D distance from each other attract each other because most of the vector is the 2d distance. Objects in different planes but at no 2D distance (right on top of each other) exert no gravity on each other. One could gravitationally detect extraplanar objects at a distance but not close. That is just like dark matter.

 Now is where my physics gets sketchy. Gravity between planes would not obey the inverse square law because the extraplanar vector component is subtracted. Objects in various planes gravitationally attracting each other would still "orbit" one another but it is not clear to me how those orbits would behave: a stack of flatland shelves would be predictable, but what if some flatland planes are perpendicular to each other, or they wrinkle on 3D space. One could have one flatlander be in the same 2D location as two extraplanar others, who themselves were far distant from each other on their own plane which they perceive as flat but is actually very wrinkly in 3D.

It seems like 4D objects as dark matter should be modelable and testable. — bungston, Jun 05 2011 [edit, delete]
 — bungston, Nov 14 2012

Hey, who's accusing me of having gravitas??
 — MaxwellBuchanan, Nov 14 2012

 //I'm not sure your calculations are wrong, as such. I think your error might be in treating a gravitational mass as physically similar to an electrostatic charge.// I'm not disagreeing, but I don't see the hole in the logic. The electrostatic force between two charged particles is 10^39 times greater than the gravitational force between two protons.

 Ergo, if we add one electron to a star for every 10^38 hydrogen atoms it contains (and one proton to another star for every 10^38 hydrogen atoms _it_ contains), we will create an electrostatic attraction between them which is 10 times greater than their gravitational attraction. And that amount of charge, for a typical star, is only 10^19 electrons (or protons), and hence is one coulomb of charge. I don't see the error.

On the other hand, I do recall that if you put a charge across two plates and then move them apart, the voltage between the plates increases. So perhaps that small amount of charge, between two stars a light year apart, would entail some truly bizarrely high voltage.
 — MaxwellBuchanan, Nov 14 2012

 Okay, but here's the problem:

 So, you've pumped the star full of extra electrons. What's holding those electrons onto the star? Gravity? Okay, but all of those electrons are pushing away from each other with a force that's 10^39 times as powerful as gravity.

All of the electrons push away from each other, and away from the star, and end up floating off into space. Ergo, it's virtually impossible to maintain a surplus of electrons in a star for any length of time.
 — ytk, Nov 14 2012

Yeah, that sounds about right. Ah well.
 — MaxwellBuchanan, Nov 14 2012

 Or is it? Might not the “natural state” of such electrons be to settle into a “shell” orbiting the star, far away enough that the electrons are distributed so sparsely that the net outward force resulting from the electrons interacting with each other is counteracted by the gravitational pull of the star?

Is such a thing even possible? Or would the electrons simply expand continuously outward? Perhaps the force of the electrons on the direct opposite side of the star is always greater than the pull of gravity, regardless of distance. Or perhaps the distance is so great that another star's gravitational pull influences the electrons before they have a chance to settle.
 — ytk, Nov 14 2012

 I agree that when you add too many electrons (or protons) to a star, it will have an overall repulsion to them. However if you cut that number down, you can reach an equilibrium point where the particles are neither attracted nor repelled. For the positive star, that would be 1 proton per 10^39 hydrogen. For the star with the extra electrons, the star must be many orders of magnitude larger to hold the opposite charge. That might be on the order of 10^43 hydrogen atoms per electron, but I don't trust my source on that one.

 You could never have a stable situation with two stars exactly at this equilibrium point because charged particles with no net attraction to its "home" star would be attracted to the distant star with the opposite charge. However, once a few charged particles had exchanged, it would stabilize. There would only need to be a small net attraction to the local star since the force drops off quickly with distance.

This of course doesn't give you 10x the attraction between those two stars. Actually I think it only increases the attraction by a factor of 10^39/10^43 since for this to balance, we had to increase in size of one of the stars by that factor before separating the charge.
 — scad mientist, Nov 14 2012

 I think it's clear that this idea was posted by someone who has not thought adequately about matters.

It does, however, raise another question: does the Universe have a net charge?
 — MaxwellBuchanan, Nov 14 2012

Another question this brings to mind: If you bombard a black hole with protons to give it a positive charge, it should be possible for a proton traveling at high speed to cross the event horizon and exit again, essentially creating a secondary "proton event horizon" inside the normal event horizon. If you add enough protons you could reach the point where protons are no longer attracted at all to the black hole. Of course you’d never quite get to that state because as you get close the highest velocity protons from inside the black hole will be able to escape, so you’d reach an equilibrium where the number of protons escaping matches the number you are adding.
 — scad mientist, Nov 14 2012

 //does the Universe have a net charge?//

 I'm not sure the Universe even has a net, so it would be unethical to charge for it.

 Seriously, though: The answer would seem to hinge on whether there is some process for creating or destroying a proton or an electron without also creating or destroying an oppositely charged particle. As far as I can tell, there is not. Electrons can be annihilated by collision with a positron, but that still leaves a net charge of zero. Likewise with protons and antiprotons. Now, a proton can apparently be broken up into quark-gluon plasma, but that doesn't seem to affect its net charge.

So, if every charged particle had to be created at some point, and if it's impossible to destroy or create a charged particle without likewise affecting (or effecting) an oppositely charged particle, then the answer would seem to be no—the Universe is has a net neutral charge.
 — ytk, Nov 14 2012

Wikipedia: "The universe appears to have no net electric charge, and therefore gravity appears to be the dominant interaction on cosmological length scales. The universe also appears to have neither net momentum nor angular momentum. The absence of net charge and momentum would follow from accepted physical laws (Gauss's law and the non-divergence of the stress-energy-momentum pseudotensor, respectively), if the universe were finite."
 — spidermother, Nov 15 2012

 "Hey you, you're under arrest" "For what?" "You've obviously spent too long in the sun, and your skin's turned nearly black" "Are you for real? I am black!" "Exactly - you're under arrest - Dark Charge!"

So sorry Max - I simply can't help myself.
 — xenzag, Nov 15 2012

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