If the "Big Bang" occured 13.7 Billion years ago and light is the "Fastest" thing in the Universe how can we?

Question

"SEE" back to the time when the Universe became transparent

This question has NOTHING to do with God! Just so we are clear on that point.

Please! SOMEONE answer my question!

How can we "See" back in time if we were part of the "Big BanG" and light is "FASTER" then the expansion of the Universe??????????????????????

This is NOT a "Rhetorical" question.

I would LOVE for someone to answer this! 8-)

Roadkill Is getting close! ;-)

Alright, WHERE is the GUY or GAL with the Big Brain when you need them?

SOMEONE PLEASE "THINK" about what I am asking and try and give me an answer that will fit the question!

Sciencenu...

I think you are on to something there :-)

Mr. Quark is "DaMan" hehe 8-)

Thank you very much Sir ;-)

I will be emailing you shortly.

Answer 1

This is a very profound question and one that is resolved by the superluminal inflation of the early universe. The response is long as a result, so bear with it. You have essentially asked someone to summarize the bulk of cosmological research from about 1975 to 1995!

Ask more questions about my response if you like, but do email me through my answers page if you do, so I see them. Also a disclaimer. I am far from expert in this area since it was not my area of study. I hope I have come close enough that a true cosmologist will at nod and say to herself "yeah, that is pretty close."


The cosmic microwave background is the redshifted Planck emission (aka black body emission) from the last scattering prior to "recombination" of all those free electrons into atoms. It isn't really REcombination because the electrons had not ever been part of atoms before, but that is the word scientists use when electrons are captured by ionized atoms.

How we can see this has to do with the Big Bang (aka inflation) itself. The CMB we see is the leftover radiation from some other part of the universe that vanished over our speed-of-light horizon during a brief period of superluminal expansion (inflation). That light has been playing catch up with us ever since.

We look in all directions and see emisison about the same temperature everywhere, yet the universe is not old enough for that emitting source to have been in thermal contact in the past.

Inflation solves this quandary. Parts of the universe that were within our horizon, that is a distance less than the speed of light times the age of the universe (ie, their light can have reached us) disappeared over the horizon during inflation. Note that that did not require for anything to move faster than light. What happened was the space between different parts of the universe expanded. Some parts receded from us at faster than the speed of light, but they did not MOVE faster than the speed of light. The distinction is subtle, but important. Carried along with this space, was the the superdense superhot gas of the universe.

So now parts of the universe were over our horizon. The universe continued to expand but in a normal, sub light speed kind of way. So, light from these areas of the universe past our horizon starts playing catch up. As time goes on, more and more stuff pops over our horizon. The stuff closest to our horizon is naturally stuff that we see as it was about 13.7 billion years ago.

Inflation was somewhat just "invoked" to explain your question in the 1970's, however various observables support inflation.

1) The hyper-expansion would tend to make the universe very nearly "flat". That is it should leave a density that is neither quite enough to force the universe to stop expanding and collapse someday nor so low that it will expand forever. As the universe evolves, deviations from this flatness become more apparent. Indeed our estimates of the mass/energy density of the universe show it is flat to within our ability to measure it.

2) The structure of the universe ( its clumpiness today in terms of the distributions of galaxy clusters ) corresponds to just what one would expect if the seeds of that clumpiness were random blobs of quantum lumpiness, suddenly expanded. If the universe expanded in a more sedate manner, it would not be nearly so clumpy today. Without inflation, it is impossible to explain the large scale structure we see today, given the apparent age of the universe; it just would not have had time to form otherwise (and the amount of lumpiness in the cosmic microwave background fits in neatly too.)

3) Our understanding of the fundamental forces of physics, the strong, the weak and electro-magnetism (gravity is not as well linked to the others as the others are to each other, but is probably part of this puzzle) gives a mechanism that ought to drive inflation called symmetry breaking.

The CMB we see is the leftover radiation from some other part of the universe that vanished over our speed-of-light horizon during a brief period of superluminal expansion (inflation). That light has been playing catch up with us ever since.

Answer 2

There is alot of specualtion into the ways this happens. Some has to do with the theory of relativity and the bending of light. Others think that quantum physics is the key. What we do know is first that light bends, and so does time. Light is indeed the fastest moving thing, but there are still limitations. The further way the light gets from the source, the weaker it becomes. Also, the universe has been expanding, but not at the same speed it did during the Big Bang. So there is an end somewhere. EVen with the Hubble telescope we can see galaxies and solar systems thousands of light years away. While we may never be able to physically go to them, we can observe them and use equations to measure their movements. The better technology we get, the further we can see.
Some even speculate in quatum physics and the string theory, that you can warp with time or bend it to see the other end. It would be like taking a piece of string and holding one end next to the other. But our technology and knowledge is no where near that yet.

Answer 3

If you believe the big bang theory (which I'm not sure I do) then the Universe began as an infinitely small singularity and "inflated" to the size of a grapefruit after which it has been expanding at the speed of light (or perhaps even faster) ever since. This means that the outer edge is traveling at essentially light speed and according to special relativity, essentially little or no time has elapsed for the outer edge at all. Thus the outer edge is a sphere that is ~13-15 billion light years in radius expanding at (near) light speed that "time forgot". Therefore it remains as a hot plasma just as it was at the start of the big bang, and it has been radiating light just as you would expect a hot plasma to radiate, all during its journey from the start of the big bang to where it is now. Because it is traveling at near light speed, its radiation is severly redshifted, with its ordinary light wavelengths now redshifted into the radio wave part of the spectrum. We can only see back to the inner edge of this expanding hot plasma because that is where the tranparency of space ends. The sun is a giant ball of hot plasma, and so we cannot see beyond the "surface" because hot plasma does not transmit light. I want you to try to imagine the Sun, in the next few seconds, immediately attaining near light speed, and traveling away from us. You would be able to see it the whole time from the moment it left the solar system, all the way to 15 billion light years from here, wouldn't you? But it would get dimmer and dimmer as it receded, and its light would be severly redshifted, wouldn't it? And even after it made it to 15 billion light years from here, you still couldn't see past its surface, could you? It is the same with the primordial plasma. I hope this helps.

Answer 4

First define what you mean by, transparent. But beyond that, you qualify your question by stating that it has nothing to do with God.
If you are asking ,what was there before the "big bang", then you are running into a paradox. Our "science" agrees that it is impossible to have an effect without a corresponding cause. If you follow that "fact to its' logical conclusion, you can't have a "bang" without a corresponding "cause" of that bang. Science tells us that the cause is irrelevant to good science... because if that question is addressed
a name must be applied to that cause. But then if that part of the equation is factored in as "x" and you give that factor a name, what do you call it ? Roseanne Barr ? See the paradox.
Oh, the farthest we see with our 'scopes of every kind is about 9 BILLION years NOT thousands ... sheeeeeeeeeeeeze !

Answer 5

Because that part of the universe is 13.7 billion light years away, so the light has been travelling since the early times of the universe.

Answer 6

We can't see back in time or forward in time. We can only see where moving light particles are right now. The only thing that light has to do with time is as a unit of measure. The past and the future don't exist. One will never occur again and one probably will. We can calculate where light particles will be barring any interference by gravity. We can also calculate how long it will take us to drive 100 miles. Big deal.

Answer 7

you can't really see the universe become tranparent. But the rate of expansion balancing the speed of light creates an event horizon limiting the size of the visible universe. I am not quite clear about the math on this one but the idea is out there anyhow.

Answer 8

We cannot see back to the time when the universe "became transparent."

We can only estimate the time that it took for the furthest objects we know of to reach that distance assuming their velocity has remained consistent since the big bang.

It may well be older than these estimates, but it won't be younger.

Answer 9

Some good answers above. horizon gets into things you can
search on the web - Stringy universe, M theory, Ed Witten, and Branes.
All theory of course, but very interesting. It is interesting that the movie/TV series Dr. Who which is really old, has him as a time/space traveller, which would be possible under the "new" M theory equations...

Answer 10

Because whatever object is now at the "edge" of the universe from out perspective is moving away at nearly the speed of light. So the light this object emitted 13.7 billion years ago is now only reaching us.