Is it possible that the universe is infinately large, and that new matter is constantly being produced from one or more points and expanding outwards, continuously producing new galaxies and such? Like a fountain constantly feeding new particles into the universe? So that "the big bang" is a continuous process?
A lot of things are "possible" but what you are describing is not Big Bang theory. AFAIK we have never observed particles/energy just appearing out of nowhere.
Originally posted by C Hess Is it possible that the universe is infinately large, and that new matter is constantly being produced from one or more points and expanding outwards, continuously producing new galaxies and such? Like a fountain constantly feeding new particles into the universe? So that "the big bang" is a continuous process?
You may not know this but what you are describing is a variation on the steady state theory that I once heard of that tries to allow both the steady state theory to be true while explaining the Doppler shift that proves the universe is expanding.
Unfortunately, for that theory, it doesn't even begin to explain why the most distant galaxies visible to us consistently all appear younger than those much closer to us. That observations alone rules that theory out as, if the theory was true, we should be seeing no shortfall of young galaxies relatively close to us while seeing plenty of very old galaxies out of the most distant ones.
Pity. I wish that theory was true because I like the idea of the universe being such that that intelligent life could potentially perpetuate forever just by space traveling from one planet to another rather than the second law of thermodynamics making all life inevitably come to an end.
Originally posted by humy Pity. I wish that theory was true because I like the idea of the universe being such that that intelligent life could potentially perpetuate forever just by space traveling from one planet to another rather than the second law of thermodynamics making all life inevitably come to an end.
Yeah, that thought crossed my mind. Thank you for a good answer. 🙂
You wouldn't know the name of whomever proposed this variation of steady state theory?
Originally posted by KazetNagorra A lot of things are "possible" but what you are describing is not Big Bang theory. AFAIK we have never observed particles/energy just appearing out of nowhere.
This is totally a different thing, but I thought virtual particles had been observed (or the effect of them). Have I misunderstood something?
Originally posted by C Hess This is totally a different thing, but I thought virtual particles had been observed (or the effect of them). Have I misunderstood something?
What you're describing in the OP isn't virtual particles.
People like Newton worried about this. Once they'd stopped thinking the earth was in the centre of the universe with celestial spheres around it, with stars representing holes in the outermost sphere through which one could see fire, then the new theory of gravity appeared to have to explain why the net gravitational field was more or less zero. If it is not then it is unstable to collapse. An infinite universe with a more-or-less constant density of stars seemed to fit the bill. The problem is that then one needs an explanation of why the universe wasn't completely full of light. If there are a constant density of stars which start emitting light at some time t = 0 then the amount of light passing though any given point at some later time t will be proportional to t. So there's a question of why the universe isn't blindeningly bright. A non-steady state universe solves this problem by not having the universe existing infinitely far in the past.
Originally posted by C Hess This is totally a different thing, but I thought virtual particles had been observed (or the effect of them). Have I misunderstood something?
I think what Kazet is getting at is that for net energy production a conservation law has to be broken. In fact for net particle (as opposed to anti-particle) production we pretty much need physics beyond the standard model (CP is violated but not strongly enough). So you'd need a mechanism whereby the expansion of the universe generates energy. This isn't that unreasonable, I think most theories involving dark energy have this. But then you need some way of turning your dark energy into matter.
Virtual particles come in a particle anti-particle pair, unless you have a handy black hole to drop the anti-particle into then all that happens is that they annihilate into nothing again. Very rapid expansion could maybe do this, but that would involve some kind of big rip scenario and not the relatively gentle expansion we have now. Also you'd have equal numbers of anti-particles and need some way of getting rid of them.
So basically the current rate of expansion of the universe is too gentle.
Originally posted by DeepThought I think what Kazet is getting at is that for net energy production a conservation law has to be broken. In fact for net particle (as opposed to anti-particle) production we pretty much need physics beyond the standard model (CP is violated but not strongly enough). So you'd need a mechanism whereby the expansion of the universe generates energy. This ...[text shortened]... etting rid of them.
So basically the current rate of expansion of the universe is too gentle.
I love this place. I do. Thank you for clarifying these things.
Just one question. If you have a "fountain" of particles shooting out from a fixed location, wouldn't the effect be the same as during the initial big bang, a rapid expansion outwards from that infitesimally small point? Wouldn't that make it possible for one (particles or anti-particles) to cancel the other out continuously? I'm thinking like waves of randomly alternating particles and anti-particles moving outwards from this central point.
I mean, hypothetically, ignoring the problem humy described where apparently younger galaxies appear where they should be older, and vice versa. I didn't know that.
Originally posted by C Hess I love this place. I do. Thank you for clarifying these things.
Just one question. If you have a "fountain" of particles shooting out from a fixed location, wouldn't the effect be the same as during the initial big bang, a rapid expansion outwards from that infitesimally small point? Wouldn't that make it possible for one (particles or anti-particles) to c ...[text shortened]... parently younger galaxies appear where they should be older, and vice versa. I didn't know that.
Then there is the multiverse hypothesis where our universe was spawned by a black hole in a parent universe and our universe has physics laws almost but not exactly the same as the parent and black holes in our universe spawns daughter universes, there seen as a white hole which is what we would observe as a big bang. The idea there being the universe IS infinite, just not OURS. Each daughter universe would have a beginning and an end game but the whole goes on forever like a garden sprouting seeds of the next generation.
Originally posted by sonhouse Then there is the multiverse hypothesis where our universe was spawned by a black hole in a parent universe and our universe has physics laws almost but not exactly the same as the parent and black holes in our universe spawns daughter universes, there seen as a white hole which is what we would observe as a big bang. The idea there being the universe IS in ...[text shortened]... an end game but the whole goes on forever like a garden sprouting seeds of the next generation.
Hypothesis, or rather speculations... We just don't know...
Unfortunately, for that theory, it doesn't even begin to explain why the most distant galaxies visible to us consistently all appear younger than those much closer to us.
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How do we know that this is consistently the case? Wouldn't we have had to look at at least a few hundred different galaxies in order to make that determination? Or have we done that already?
Originally posted by vivify How do we know that this is consistently the case? Wouldn't we have had to look at at least a few hundred different galaxies in order to make that determination? Or have we done that already?
I don't know enough about observational astronomy to say this with any high degree of infallibility. However, by looking at the spectroscopic properties of stars one can tell their metalicity, metals in astronomy are all elements heavier than helium, so carbon and oxygen are metals to an astronomer. There are three populations of stars population I which have high metalicity, the sun is a population I star. Then there are population II stars, they have lower metalicity and some have been observed that are up to about 13 billion years old. Population I stars are hypothetical, no one has ever observed them. They are the first generation of stars and even very massive population I stars would have burned using the proton-proton chain, rather than the CNO cycle. So, the older the galaxy the higher the metalicity. Astronomers have done surveys of millions of galaxies. I would venture, but cannot categorically state, that they will have done surveys of the metalicity of distant galaxies by spectroscopy. I would expect the metalicity to decrease more or less inversely with distance. So they can estimate the age of galaxies and compare that with their overall redshift. Assuming that this has been done, which I find highly likely, then it will have been done on statisically significant numbers of galaxies.
23 Mar '15 16:06
Dumb question about the big bang
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