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After reading a number of scientific articles about far distant galaxies and the

estimated age of the universe I began wondering how we could supposedly

see light from objects that are 12 billion light years or so away. This is

supposed to be light from nearly the beginning of time and space.

If we agree to believe that the big bang actually happened then this would

mean that at some point we were much closer (cosmologically speaking)

to those distant objects.

Since matter travels at a mere fraction of the speed of light is seems

somewhat dubious that any light emitted from that object at the beginning

of time, as we know it, would not already have passed us a long, long, long

time ago.

We have developed many tools for measuring distance from relatively

nearby objects. I suspect that these work well up to a point, at which

they start to break down somehow.

Could it be that using light to measure distance works well when

objects have been relatively close together since the beginning and

then breaks down when objects become very far apart ?

Maybe the big bang never happened and objects that are far away have

always been far away ?

Doesn't the fact that these supposed far distant objects are 12 billion light

years away mean that the universe is far older than 14 billion light years

or have these objects been moving at the speed of light ?

I found an article in Wikipedia which attempts to explain this but I'm not

sure I buy it. Look for 'Metrical_expansion_of_space'.

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If we agree to believe that the big bang actually happened then this would

mean that at some point we were much closer (cosmologically speaking)

to those distant objects.

I agree that the big bang actually happened. The big bang, as cosmologists normally understand it, does not involve having matter move (except for individual random motions).

It is true that distant objects (distant material in general, anything emitting light) was much closer.

It didn't move. But it got farther away.

Google "wright balloon model" and watch it to see how.

Since matter travels at a mere fraction of the speed of light is seems

somewhat dubious that any light emitted from that object at the beginning

of time, as we know it, would not already have passed us a long, long, long

time ago.

Since matter is not traveling (traveling matter has somewhere it is going, that it is getting closer to) it is irrelevant that it can only travel at less than c.

In General Relativity, distances can increase at greater than c. And the longer distances typically do

Again you should watch that 3 minute balloon model movie and think about it. The little wiggly things are photons of light traveling at a fixed speed over the balloon surface. Often the galaxy that they are traveling towards is getting farther away.

http://www.astro.ucla.edu/~wright/Balloon2.html

But notice that as expansion slows, after a long time, the photon will begin to make progress and get closer to its destination. It's a great lesson for all of us. If you hang in there and keep trying you may get there.

Look for 'Metrical_expansion_of_space'.

That is a bum steer, Purin. You mean look for Metric_expansion_of_space

If you google what you said, you don't get anything. If you google what I said, you get the Wikipedia article on the metric expansion of space.

By and large it is a pretty good article.

Edited by Martin
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If the light from a galaxy took 13.66 billion light years (almost the age of universe) to get here, it was emitted when it was 0.205525 billion light years away and is now 43.762 billion light years away. This is not because of the movement of galaxies but because of the expansion of space.

The universe was more dense long ago but the big bang is currently looked at as not coming from a singularity. At the edge of the observable universe we would probably see a similar view in every direction as we do from the Milky Way.

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I understand the balloon concept and have seen the applet on the net. I have

a little difficulty mentally translating a 2d surface to a 3d world we actually live in.

Since the light from the far distant object is not all that far away at an earlier time

the speeds of the far distant expansion should not be an issue as with a closer

proximity expansion. Light from nearby galaxies has no problem getting here. Why

would it be any different ?

It still seems that it should exceed the speed of the early expansion and reach us in fairly short order in the distant past.

Which begs the question of being able to see the

same light photons at two widely separated time intervals.

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If the light from a galaxy took 13.66 billion light years (almost the age of universe) to get here, it was emitted when it was 0.205525 billion light years away and is now 43.762 billion light years away. This is not because of the movement of galaxies but because of the expansion of space.

The universe was more dense long ago but the big bang is currently looked at as not coming from a singularity. At the edge of the observable universe we would probably see a similar view in every direction as we do from the Milky Way.

------------------------------

The X-ray image of the distant cluster is comprised of just 280 photons—individual parcels of light—collected during a 12.5-hour exposure. By comparison, on a sunny day the human eye is flooded by about 10 quadrillion photons per second.

http://www.ur.umich.edu/0405/Mar07_05/02.shtml

-------------------------------

Admittedly, I am not convinced BBT is valid, no longer wish to argue the point but am really confused on this 'distance' relationship to what we think we are seeing. I understand that objects in an expanding U, will be in different places 2-5 or 10 billion years in the past and I understand some think emitted energy travel time has changed from today's -C-, but has this been proved.

If we observe photons, which are not very many from more distant objects, that object emitted those photons according to there distance was momentarily at a precise distance from the receiving object. Where it was before, that energy has long past us by and where it is today will reach us in time, but at the time that photon was released is measurable at a constant -C- (186,200m/p/s).

Using the same site and the diagram of higher red shifts per distances; How could the observation be the same from observations made from distant points. Regardless how you understand 'center' with regards to a self contained U in rapid expansion, said to be in all direction (not material) then the effects of expansion IMO cannot be equal in every quadrant of that object, sphere or other wise.

purintjp;

"Which begs the question of being able to see the

same light photons at two widely separated time intervals."

Under any scenario, light (energy) reaches you eyes or whatever lens from ONE object, in that fraction of time. Your not going to receive any energy (photon) from one object in more than one time. The ten quadrillion or so photons effecting the earth each second where sent out 8 minutes ago, which our planet actually runs into after 8 minutes of travel around the sun @ 1,000 m/p/h...Even reflected light, are new photons such as you see from a blue sky or off the moon. At least thats the way I understand it....

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Admittedly, I am not convinced BBT is valid, no longer wish to argue the point ...

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It is my belief that we will never be able to integrate the universe through

mathematics. It is a victim of its own precision. Everything seems to

break down when it approaches zero or infinity. There seem to be levels

of what I like to call relative infinity or relative zero. We are insulated

from these areas and for good reason. Relative infinity is easily less than

1000 light years and any attempt to derive anything of practical value is

probably a waste of time. Our best bet is the near practical zero of

Quantum mechanics which may offer some useful practical applications

for energy production or other scientific use. The single most important

thing for science to discover is whether infinity or nothing (zero) truly

exists in our relatively closed system. Only then will we understand the

unfathomable universe.

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