Can we see the big bang?

Hi,I have a question...If I were to build a telescope that could produce images of things about say... 14 billion light years away... What would I see?According to the Big bang theory, shouldn't I just see a singularity and nothing else?Thanks.

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From what I understand, looking out such a telescope would only tell you how far the universe had expanded. You are looking at the consequences of the big bang not at the big bang itself. Also from what I understand, the big bang is inferred from evidence which leads to that conclusion

Hi! Welcome to EvC No, you can't sadly. I assume you have heard of the Cosmic Microware Background Raditaion (CMBR)? The "echo" of the Big bang, as the popular science guys put it.Up until about 300,000 years from the BB, the universe was sufficiently hot that atoms (essentially hydrogen and helium) could only exist in a totally ionised state - a plasma. With free roaming electrons and protons, space was opaque to the passage of photons. They would continually interact with the charged particles. Thus there was no free path for photons through space and optics impossible.At a particular moment, the universe cooled sufficiently for the electrons to be captured by the protons, forming neutral hydrogen and helium. We call this period "recombination". At this moment, all of those photons bouncing between the charged particles became free and could traverse the universe.The CMBR is the remnant of those first ever free photons in the universe.So the CMBR is the furthest back we can see... anything earlier than 300,000 years is not visible electromagnetically.Great question by the way

Thanks for your replies.So assuming we did have access to such a telescope, does that mean that beyond that region of space, we wouldn't be able to see anything?I just can't get my head around the fact that when we view distances, it involves time (on such large scales), and therefore the further you look distance wise, the further you must be looking back in time.In my reasoning that should mean the further out we look, the smaller space should get, since it apparently began from a singularity and is continually expanding. Even if the 300,000 year limit prevents us from seeing the BB itself, shouldn't we at least be looking "towards" it so to speak?

Hi Abbas, cavediver is a little busy at the moment, so I figured I'd reply We do have access to such a telescope. Here a handy little picture of what it sees. We can see something, we see the bacground radiation that cavediver mentioned. It's travelled a long way and spread out by the time it reaches us so its not very bright. If a relativitist gets a sniff at this comment they'll have a field day. They will delight at confusing you with comments like how time and space are are part of the same thing and that in a sense there is basically no difference between one second and 300,000kms (186,800 miles). I don't want to speak for them, and that might not be entirely accurate, but its the kind of thinking you might have to prepare yourself for if you are exploring Big Bang territory! We are looking 'towards' it wherever we look. Since space itself is expanding, the big bang happened 'everywhere'. Look at your computer monitor. If we were to trace the complete history of that part of space you will find it is the 'location' of the big bang, your monitor is thus the centre of the universe. Don't worry, I'm the centre of the universe too!It is very confusing, but that's to be expected, right.I am not an expert though, so take nothing I say as gospel, I often miss subtle or important points here, I just thought I'd provide some starting answers for you.

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When you want to reply to a certain person you can click the 'reply' button at the bottom right of their post. Some say it's green some say it's blue but if you press that when you reply, the author of the post will be notified by email that you have replied. Welcome and enjoy EvC!Edited by Modulous, : wow, my html screwed up the board. Close your quotes in anchor tags, people.

Ultra cool graphic, Mod I love it... do you see how it is modified from my usual globe picture? North Pole (big bang) at the left end, then rather than closing up to a South Pole at the right end, it remains open and flares outwards.This is a depiction of a finite universe with infinite expanion caused by the cosmological constant (dark energy).

Absolutely! And it does. But the universe always surrounds us, so this smaller space still takes up the entire sky. It is just that distances *across* the sky are not as big when you look deep into the universe (early times). The consequence of this is that the most distant galaxies look bigger than closer galaxies!!! A purely optical effect of a small early universe. Yes, we are

Let's take this a bit further (pun).
After you look in one direction and see the most distant past you can, then turn the telescope 180 degrees around and look in that direction and look into the past. Then, think about how far each one is from each other through you (mucho light years), and then think how far they are from each other at that point in time (a few feet?). In the mucho distant past, matter was expanding from each other and was very close to each other.I haven't read this apparent paradox anywhere, and would be interested if anyone has named this paradox.

It isn't thought of a paradox, just a natural consequence of the geometry of the universe. I mention it in msg 7, two posts back.At recombination (400k yrs), the observable universe is quite a bit bigger than a few feet between poles, but still substantially smaller than the "expected" 14billion x PI lyrs.

cavediver,

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But the universe always surrounds us, so this smaller space still takes up the entire sky.

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I guess the image modulus posted is supposed to represent this concept, with us looking backwards into a "cone" of sorts. That's fine for a 2D representation, but I still can't grasp how that maps out into 3D. As we look out at a seemingly infinite expanse of universe, we're supposed to be looking towards singularity, still doesn't compute for me.Edited by Abbas Ibn Firnas, : Got the point.

Ok, you are standing on the north pole and imagine you can see around the curvature of the earth. So you can see London if you look that way, and you can see new York if you look around 90 degrees right of London. Look the oposite direction to London and really strain your eyes and you can see Australia. Really strain your eyes hard enough, and in any direction you will see Antartica. If you could see through all the snow you could see the south pole from any direction! The flag pole at the south pole would be stretched all around you because of the optical effect.This is what is happening as we look through space. Our line of sight follows the curvature of the universe.