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The last years we find some objects like this : MACS0647-JD which are more than 13 billion light-years away from us.

This means that the picture we get was created only some million years after the Big Bang.

Why can we see objects like this in all directions? Shouldn't those objects be close to each other?

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  • $\begingroup$ What do you mean by "This means that the . . . Big Bang?" $\endgroup$ – HDE 226868♦ Sep 1 '14 at 12:30
  • $\begingroup$ The light that we see is 13 billion years old. Big Bang happened 13.7 billion years ago. So the light of these stars was created in the early space, some million years after the Big Bang. $\endgroup$ – TheCuriousAnt Sep 1 '14 at 13:04
  • $\begingroup$ If the light you get is 13 billion years old, then most likely that object (if not already dead) would be much further away by now. $\endgroup$ – harogaston Sep 1 '14 at 22:25
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    $\begingroup$ Yes I know this, but my question was how can we find early space objects with so huge distances between them. I was thinking that the early space was a something like a relatively small sphere, but it seems that this is not the case. $\endgroup$ – TheCuriousAnt Sep 2 '14 at 8:41
  • $\begingroup$ @TheCuriousAnt Early space was very, very tiny. Then the universe entered an inflationary period, and it became very, very big. $\endgroup$ – HDE 226868♦ Sep 2 '14 at 12:07
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I'm going to try to expand a little on my comment regarding inflation. Let me know if it is in any way useful.

Just after the Big Bang, the universe was quite small. Tiny. Smaller than the head of a pin. Then the universe reached the grand old age of $1 \times 10^{-36}$ seconds old, and it had a little bit of a growth spurt. Between $1 \times 10^{-36}$ seconds and $1 \times 10 ^{-33}$ seconds, it expanded at an incredible rate, reaching a size closer to its present-day size.

Before inflation, the universe was - well, we don't really know. Prior to $1 \times 10^{-43}$ seconds, all four fundamental forces were unified. But after inflation, they slowly (relative to the time scales we're talking about) became the distinct forces we know today.

Another curious thing happened after the inflationary epoch: baryogenesis. Prior to this, the universe had been made out of an exotic quark-gluon plasma. Now, some of the matter (now spread out throughout space) formed quarks which grouped together to form baryons - some of which are the protons and neutrons we know today. Later on (but still within the first second), electrons formed, and, gradually, the particles we know today came into being.

The objects you're talking about formed 420 million years after the Big Bang - way after inflation! They were never close together; however, their constituent particles were. The reason they are so far away now is mostly because of inflation, but also partly because of the current expansion of space, which comes courtesy of dark energy. The reason we can see these objects in all directions is because inflation made space expand in every direction, so matter is, therefore, in every direction.

I hope this helps.

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  • $\begingroup$ Thank you for your answer @HDE , now its more clear. By searching about inflation I also found this picture: Inflationary Universe which helped me understand this topic better. $\endgroup$ – TheCuriousAnt Sep 3 '14 at 9:22
  • $\begingroup$ FYI, @TheCuriousAnt, there is another user named HDE, and I think this comment might have reached him instead! $\endgroup$ – HDE 226868♦ Sep 10 '14 at 0:08
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the big bang did not happen in one place, it happened everywhere, and since then space has been expanding. so the stars that where formed shortly after the big bang where everywhere in space, but space was smaller. therefore you can see them everywhere if you look 13 billion light-years away, because they where everywhere.

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  • $\begingroup$ To add. The rate of expansion just after the Big Bang was enormous. So, after a 0.7 billion years, the Universe would have been fairly big. $\endgroup$ – Yashbhatt Sep 1 '14 at 15:45
  • $\begingroup$ The stars weren't "everywhere". They formed millions of years after the Big Bang. $\endgroup$ – HDE 226868♦ Sep 2 '14 at 16:08

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