Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 12/03/2012 09:17:01
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Claus Schertel asked the Naked Scientists:
Hi guys,
Is it possible to map the centre of the universe, where the big bang actually happened? And what is there these days?
Thanks and keep up the good work.
Claus
What do you think?
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The universe has no center. The reason why is because space did not appear from one point alone, but appeared as the space between objects exponentially increased. If you like, there was an infinite amount of centers proportional to the infinite amount of degrees of freedom provided by an ever-expanding universe.
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So to fully answer your question, big bang happened everywhere.
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I don't think it is possible to map. But I'm not sure, as always :)
You have the CBR (Cosmic Background Radiation) to use, possibly, although I don't see how?
If there was an inflationary period, which the CBR is one strong contender for as it is perfectly redshifted to microwave wavelengths from that inflation, then it happened 'everywhere simultaneously' if we pretend that it was 'photons' getting redshifted. There was no exact center to it as it was 'space' itself that 'stretched' in all directions. Every 'photon', in that first instant, would then see the same as we see now looking out at the universe. That everything is moving 'away' from us, but then so extremely much faster as it was 'FTL' in all directions. It's like every 'photon' would had a 'shell' of 'space' that just grew into smithereens, stretching it out, and redshifting it. Well, it's better described as waves, but 'photons' are expected to have a singular existence :) whereas 'waves' can be quite elusive to pinpoint.
and if you can't use the CBR?
What can you use?
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eh, better add that due to 'particles' created at that first instant we also had the 'gravitational potentials' to keeping them together. So the inflation would to 'matter' have been more like 'clumps of particles' watching that 'space' grow into eternity around them
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I prefer the BING BAG theory
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The universe has no center. The reason why is because space did not appear from one point alone, but appeared as the space between objects exponentially increased. If you like, there was an infinite amount of centers proportional to the infinite amount of degrees of freedom provided by an ever-expanding universe.
Thanks for the answer. I had the romantic (naive?) picture in mind where everything is concentrated in one point that than "explodes" in the big bang and the matter flies away from (expands) it in every direction like the skin of a balloon. Thus, I thought there might be a center of this balloon that one could possibly map by looking at the distribution of galaxies (on the balloon skin, to stay with the picture).
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I don't know. Maybe you can find a 'center' using more dimensions? But I don't think it's possible to define it that way for the four we have? If every little particle watch all other particles recede in a sphere like way, with the exception of those gravitationally bound to each other, which soon will change for any observer as matter clumps together and create gravitational time dilations relative each other?
Which particle would you define as the center?
and using 'time' to pinpoint it has to do with your beliefs :) Either you believe there to be a background of 'time' on which we see 'streams of arrows, aka time dilations' or you think of it as a strictly local phenomena. If so, every 'particle', including bosons as light, depending on direction relative each other (Seen as a 'system' and according to theory) might be what creates a local arrow. And each one will see all others arrows differently, although all will 'fit' each other if 'super imposed'.
And what would connect them to each other would then be the radiation describing them.
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The universe has no center. The reason why is because space did not appear from one point alone, but appeared as the space between objects exponentially increased. If you like, there was an infinite amount of centers proportional to the infinite amount of degrees of freedom provided by an ever-expanding universe.
Thanks for the answer. I had the romantic (naive?) picture in mind where everything is concentrated in one point that than "explodes" in the big bang and the matter flies away from (expands) it in every direction like the skin of a balloon. Thus, I thought there might be a center of this balloon that one could possibly map by looking at the distribution of galaxies (on the balloon skin, to stay with the picture).
Well the balloon analogy can still be used. Blow a balloon up, fill in dots very dense to each, let the air out and most of the surface of the balloon will appear dark. Blow into the balloon, and as you do, the space between the dots become visible. Each space between each dot is in fact a center... a finite one in this case however. The universe is infinite in directions - the space appeared between the objects (particles of mass) as the universe expanded. There couldn't be a center see.
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The universe has no center. The reason why is because space did not appear from one point alone, but appeared as the space between objects exponentially increased. If you like, there was an infinite amount of centers proportional to the infinite amount of degrees of freedom provided by an ever-expanding universe.
Thanks for the answer. I had the romantic (naive?) picture in mind where everything is concentrated in one point that than "explodes" in the big bang and the matter flies away from (expands) it in every direction like the skin of a balloon. Thus, I thought there might be a center of this balloon that one could possibly map by looking at the distribution of galaxies (on the balloon skin, to stay with the picture).
Well the balloon analogy can still be used. Blow a balloon up, fill in dots very dense to each, let the air out and most of the surface of the balloon will appear dark. Blow into the balloon, and as you do, the space between the dots become visible. Each space between each dot is in fact a center... a finite one in this case however. The universe is infinite in directions - the space appeared between the objects (particles of mass) as the universe expanded. There couldn't be a center see.
Don't forget, we live in a 4-dimensional spacetime, so if you use the balloon analogy for our universe, picture the surface of the balloon as our 3D space, and the inflation as the 4th dimension "time". The air in the balloon represents the past, where the surface of the balloon was moments ago. The air surrounding the balloon represents the future, where the surface of the balloon will be when you keep inflating it. So in a way, there is a center in our 4D space, and that's at t=0 or "the moment of the bigbang". You should not ask "Where is the center of the universe?" because then you're only taking 3 dimensions into account. You should be asking "Whenwhere is the center of the universe?" and the answer to that question is "Everywhere at the moment of the big bang".