early univer object detection - physics grad or above plz?

Question

the most popular theories hold the univers to be around 13.7 billion years old, give or take .2 billion.

I occasionally read of deep space objects in the neighborhood of 9 or 10 billion or more light-years distant, with accompanying "we're looking back into the past shortly after the big-bang" statements.

Considering an object, say, at one edge of the universe, at 3.7 billion years of age. By relativity the universe would have not been more than 7.4 billion light-years in extent.

By Michelson-Morley, light from such an object would take not more than 7.4 billion years to reach its destination, even if the universe is bigger by the time it gets there.

How do astronomers get around this when they claim to be able to see back that far? Are they looking at reflected/refracted light?

details plz
only a convincing answer will get best answer. otherwise you'll have to vote.

Sorry, no good answers yet.

William F. did you comprehend the question? Because if you did, you wouldn't ask why I think the matter "got here first." I don't.

Peter T and Johnnie B., I'm not convinced, but thanks for the honest answers...

and Arkady I expected such scholastic snobbery, but I graduated university before age 20 and I'm not impressed by it.

The notion of an "edge of the universe" is not an important part of my question, only the supposition that 10 billion years ago, nothing was 10 billion light-years apart.

Michelson-Morley is the experiment that demonstrated the constancy of the "speed of light" regardless of the relative velocities of its source and its destination. I've never heard that expansion of space could influence this. Perhaps it is theorized, but airy referrals to "referenced works" won't convince me of that on this site.

No best answer yet. time extended.

Answer 1

These are difficult things to understand, and here's a further complication. In addition to the expansion of space itself which creates the red shift, the constancy of the speed of light is different than you might imagine. You have to understand a little about relativity. Light is the speed limit of the universe (at least as we understand it in classical physics.) This means just that. Here's a thought problem for you. You leave earth at 3/4 of the speed of light. A sister ship leaves at the same time going in the opposite direction at 3/4 of the speed of light. Can you communicate with that sister ship? It would seem that the separation distance between the two ships is increasing faster than the speed of light, but is it? In fact you can communicate, and here's the proof. You would have to agree that either ship can still communicate with earth, and that earth can communicate with either ship. Since that is true, it means they communicate with each other! The speed of light is not additive. The edge of the universe, which is a relative thing, is the point at which from your own perspective space is expanding at the speed of light. When an astronomer says that something is 10 billion light years away, he is measuring the red shift in real time. It would probably be better to say that the light coming from that object has covered 10 billion light years of space. Does that mean the object is now 20 billion light years away? No. Something that distance by the way, would have an enormous red shift and be retreating at a significant percentage of the speed of light.

Answer 2

These are difficult things to understand, and here's a further complication. In addition to the expansion of space itself which creates the red shift, the constancy of the speed of light is different than you might imagine. You have to understand a little about relativity. Light is the speed limit of the universe (at least as we understand it in classical physics.) This means just that. Here's a thought problem for you. You leave earth at 3/4 of the speed of light. A sister ship leaves at the same time going in the opposite direction at 3/4 of the speed of light. Can you communicate with that sister ship? It would seem that the separation distance between the two ships is increasing faster than the speed of light, but is it? In fact you can communicate, and here's the proof. You would have to agree that either ship can still communicate with earth, and that earth can communicate with either ship. Since that is true, it means they communicate with each other! The speed of light is not additive. The edge of the universe, which is a relative thing, is the point at which from your own perspective space is expanding at the speed of light. When an astronomer says that something is 10 billion light years away, he is measuring the red shift in real time. It would probably be better to say that the light coming from that object has covered 10 billion light years of space. Does that mean the object is now 20 billion light years away? No. Something that distance by the way, would have an enormous red shift and be retreating at a significant percentage of the speed of light.

Answer 3

It'll be hard to convince you without knowing what your flawed understanding of theory is based on. The very concept of "one edge of the universe" is one that does not agree with theory.

More importantly, where does the statement "By Michelson-Morley, light from such an object would take not more than 7.4 billion years to reach its destination, even if the universe is bigger by the time it gets there." come from?
This implicitly assumes that space is not expanding, which flat out contradicts theory - I hope that much is obvious. As light - I'll refer to it in its particle form, photon, for ease - travels, space itself expands, which has several effects. Most importantly in this case, the distance between the photon and it's destination grows. The photon is still limited to travelling at the speed of light. So obviously, the time it will take to get there has increased.

This is not an entirely accurate explanation from a theoretical point of view, but If you feel you're up to studying refereed papers on the subject, I'll ask you to do your own library research.

Edit:
You are an arrogant twit.

Read up on "Michaelson-Morley" and "metric expansion of space".

Maybe you will prove capable of grasping how one does not disprove the existance or nullify the effects of the other, though I doubt it.

Answer 4

So what I hear you saying is that when the observable Universe was 3.7 billion years old the distance from horizon to horizon was 7.4 billion light years and that since the speed of light is the same in all reference frames it should only take 7.4 billion years for light to cross from one side to the other.

I don't think this second part is correct. Since space itself is expanding I'd say the light does take longer than 7.4 billion years to cross, the "goal posts" have shifted.

In any event I'd say that when an object is reported as being 10 billion light years distant what is really meant is that it is at a certain redshift and that light has been travelling for 10 billion years to reach us from the region where the object was when the light set out. Of course the region where we are and the region where the object was were much closer together when the light set out. In the mean time all manner of things may have happened in that region and the object we observe may have changed utterly.

Interested to see what others say.

Answer 5

The one who answered after Kim was an echo. The light was neither reflected nor refracted it was the original light with a large red shift and a stretched wavelength. The conclusions of astronomers may or may not be accurate, it all boils down to consensus of the majority of the scientific community. You have every reason to be sceptical of a lot of the theories that are put forth. Recently I read a report of a group of astronomers who claimed that their analysis of views from the Hubble telescope revealed that about two billion years ago the expansion of the universe slowed down, but instead of retreating, the expansion actually sped up, they claimed that this was because dark energy overcame the gravity of dark matter. When asked where this dark energy came from the spokesman of the group replied that it came from nothing. It is small wonder why you are looking for reasonable explanations of what is really going on.

Answer 6

Sorry to burst your we are so smart bubble but

How can you see light from an event 13 billion years ago?
considering how long the dust (matter) and then the galaxy
(matter) eventual rise of man and the building of telescopes
to point out into space -- towards the beginning of all

Based on the velocity of LIGHT and the velocity of Matter
moving thru space for billions of years

What the hell makes you believe the Matter got here first?

Answer 7

Well over such a great distance anything is possible but if there are large suns that the light must pass the light is bent . If it pas es a black hole near enough that it bend the light 45 deg. If it is bent and travels billion light years it could be traveling in a circle.

Answer 8

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