philaj Posted March 28, 2013 Posted March 28, 2013 I just finished reading about New radio telescopes that could detect light sources billions of light years away that (it says) were produced at the time of the big bang. Ok...so if everything in the universe/cosmos was produced at the same time as the big bang happened, and expansion meant that we ended up where we are now, how come the light that also happened at the same time is still billions of miles behind us? Phil 1
Chrispen Evan Posted March 29, 2013 Posted March 29, 2013 this is due to the inflation period which happened a very short time after T=0. this rapid expansion resulted in space expanding faster than light. http://www.lifesci.sussex.ac.uk/home/John_Gribbin/cosmo.htm
elfmotat Posted March 29, 2013 Posted March 29, 2013 this rapid expansion resulted in space expanding faster than light. "Expanding faster than light" is ill-defined. Nothing is actually moving during expansion, distances are just getting larger due to the time-dependent metric. There's no "velocity of expansion," so "expanding faster than light" makes no sense. 1
Chrispen Evan Posted March 29, 2013 Posted March 29, 2013 maybe not but that is the "common" terms used. and i try to make it comprehensible to the level of the question. clarification is always appreciated though.
Elite Engineer Posted March 29, 2013 Posted March 29, 2013 I would think that just because there was one simultaneous explosion that doesn't mean that there can't be different rates of "expansion" for different masses in space...just a thought.
michel123456 Posted March 29, 2013 Posted March 29, 2013 I just finished reading about New radio telescopes that could detect light sources billions of light years away that (it says) were produced at the time of the big bang. Ok...so if everything in the universe/cosmos was produced at the same time as the big bang happened, and expansion meant that we ended up where we are now, how come the light that also happened at the same time is still billions of miles behind us? Phil http://en.wikipedia.org/wiki/Horizon_problem this is due to the inflation period which happened a very short time after T=0. this rapid expansion resulted in space expanding faster than light. http://www.lifesci.sussex.ac.uk/home/John_Gribbin/cosmo.htm Something that I took 300 years to swallow (still in my throat), is that the actual Theory states that all galaxies in the universe were roughly created in the place where they are today.
philaj Posted March 29, 2013 Author Posted March 29, 2013 Thanks for the feedback, I shall read through the references and try to get my head around it. However, I was always under the impression that the theory suggested a single point expanded outwards...and if nothing can go faster than light then surely light would have at least gone with everything else...If not ahead of it. Maybe I should read those references.....
ACG52 Posted March 29, 2013 Posted March 29, 2013 However, I was always under the impression that the theory suggested a single point expanded outwards... Not outwards, and not a single point. Rather, every point is expanding away from every other point. And nothing is moving faster than light through space. What happens is that since every point is in constant expansion away from every other point, the more distance there is between objects the more space there is to expand. At some distance, the expansion takes place faster than light can traverse the always growing distance.
Chrispen Evan Posted March 30, 2013 Posted March 30, 2013 is that the actual Theory states that all galaxies in the universe were roughly created in the place where they are today. roughly yes, disregarding their own proper motion. there was less space between them though.
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