[JohnDoe]

Originally Posted by SirJac To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

I'd venture that even if there was some net negative charge on the universe, it wouldn't have any influence we can measure. If we appoximate the universe as a sphere of infinite size and give it some negative charge with equal distribution and let it play out over several billion years, what would happen? I propose that the universe can be also approximated as being conductive, as the time scale and vast amounts of empty space would allow for generally free movement of excess electrons.

Nope. You forget that the universe is expanding and that most of these electrons would not be traveling anywhere the speed of light, thus for all practical purposes charge is local

On smaller scales, we see that if we give a condutive sphere a charge with equal distribution the charge accumulates at the surface of the sphere nerely instantly due to mutual repulsion. Give that the universe is infinite and there is no surface to accumulate on, instead excess charged particles would simply be found ever accelerating at the farthest reaches, creating an outer shell around the rest of the matter in the universe.

Huh? The universe does't have a center therefore analogies to the sphere do not make sense.

	Now, applys gauss' law we see that by putting a imaginary sphere between the charged shell and the rest of the matter in the universe, the net electric feild within the sphere (which encompasses the entire observable universe) is completely unaffected by the excess charged partcles.

No center to the universe prevents you from doing this.

	As such, even if there was a net charge on the universe when it was first created the entire obervable universe would have no net charge and no net electric feild to measure.

And thus this isn't true.

Originally Posted by DewFuel To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

Interstellar elements don't really follow the rules that are found on earth. a lot of the events that created elements are accompanied without capture of electrons (since the density of these gases is extremely low, the probability of capturing an electron is also low.) but as far as hydrogen goes, most of the stuff found is charge neutral. Helium might behave funny because it has less propensity to acquire electrons than hydrogen, and it is less abundant, so i would imagine there is a larger percentage of charged helium in interstellar medium.

No. See recombination
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In reality, the universe was much smaller during recombination. In fact the cosmic microwave background emerged because ionized gasses cooled enough to combine into elements. The calculations to prove this are fairly trivial.

	But all this is kind of moot because we're still talking about chemical reactions, and if we are in this realm, then everything must be charge balanced. Any nuclear reaction, chemical reaction, or whatever you can think of requires fundamentally conservation of charge.

Yes

What we have to dig at is the creation of these particles: If there were some asymmetry during the creation of matter (the initial moments after the big bang, if you subscribe to that theory). If we limit ourselves to strictly electrons and protons, and ignore their antiparticle creation, then it should be fairly evident that electrons would require less energetic photons to be created. The temperature and density of a photonic gas would have to be much less for the production of electrons. So if I were to guess, the net charge of the universe would have to be negative.

It doesn't exactly work like this. You can't just ignore antiparticle creation because electrons are always created in an electron antielectron pair, with the exception of whatever process breaks matter/antimatter symmetry. Furthermore in many cases those particles created will immediately annihilate, so the process is actually much more complicated. Essentially the question you are interested in is if the process which breaks matter/antimatter symmetry. In particular, in most working theories, lepton and baryon asymmetry are exactly balanced, so there would not be any charge symmetry violations. There is no apriori reason to do this, other then there is no experimental evidence for charge violations during matter/antimatter symmetry breaking, and any charge violation that was not very very very very small would be visible on large scale galaxy map surveys. So it could be done, but there is no experimental or theoretical reason to do so, and the fine tuning required to make it not observable on current observations would be very very precise.

	Originally Posted by DewFuel To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	just talked to my professor, it seems particle creation is more complicated than at first glance...

Yeah. Its a bitch :P You can essentially treat the particles in the universe as a gas and then use thermodynamics to give you the information you want.

[DewFuel]

Originally Posted by JohnDoe To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

It doesn't exactly work like this. You can't just ignore antiparticle creation because electrons are always created in an electron antielectron pair, with the exception of whatever process breaks matter/antimatter symmetry. Furthermore in many cases those particles created will immediately annihilate, so the process is actually much more complicated. Essentially the question you are interested in is if the process which breaks matter/antimatter symmetry. In particular, in most working theories, lepton and baryon asymmetry are exactly balanced, so there would not be any charge symmetry violations. There is no apriori reason to do this, other then there is no experimental evidence for charge violations during matter/antimatter symmetry breaking, and any charge violation that was not very very very very small would be visible on large scale galaxy map surveys. So it could be done, but there is no experimental or theoretical reason to do so, and the fine tuning required to make it not observable on current observations would be very very precise.

They wouldn't necessarily have to annihilate each other, since momentum would be conserved: they would physically be separated. The only reason I neglected antiparticle formation and destruction was that it would conserve charge, regardless. Guess that doesn't really work, because I was reading on the conservation of baryonic matter during some of these processes, so it might not be easier to create an electron if production changes these conservation values.

Maybe the question is a bad one in the first place. Charge is a very local phenomena, so we might in essence be probing a question which has no real answer.





DewFuel added to this post, 3 minutes and 7 seconds later...

didn't know recombination was that thorough. and obviously helium would have a higher capture rate than hydrogen because of its doubly positive charge, dunno what i was thinking of earlier.

[Moriarty]

	Originally Posted by thod To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	Even if it was created equal, it doesn't mean it would stay that way. Suppose you have a pair produced by quantum fluctuation on a black hole boundary. One falls in, removing it and its information from the universe, the other escapes, adding its charge to the universe.

The infamous Hawking Radiation defense...
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Are you considering the potential charge of the hole itself?

[thod]

	Are you considering the potential charge of the hole itself?

The hole may have a charge, it may be the most strongly charged body in the universe, yet it would make no difference. Once the particle has fallen in it is effectively removed from the rest of the universe, thus the black hole provides an infinite sink.

[JohnDoe]

	Originally Posted by thod To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	The hole may have a charge, it may be the most strongly charged body in the universe, yet it would make no difference. Once the particle has fallen in it is effectively removed from the rest of the universe, thus the black hole provides an infinite sink.

Um, how do you figure? Unless you are positing that general relativity is wrong, black holes do have charge. For sufficiently distance objects you can treat them as point charges.