How can we see light from the early universe?

Question

Since the universe is expanding at much less than the speed of light (which our observations say that it is), and we started from a single infitesimal point of existence (the Big Bang), then how come we can see light from billions of years ago? Shouldn't that light have passed us long ago?

Answer 1

Simple answer:

ALL of the stars we see today came into existence long after the universe formed. In fact, to get many of the heavy elements present on earth, you need that matter to have been part of a star formation and lifecycle multiple times. (Yeah, that means that all of us were once part of a star.)

Answer 2

Imagine that the "universe" consists of a spherical shell of luminous material expanding at nearly the speed of light, and you are an observer at rest at the center of the shell. In your reference frame, any light reaching you from the shell would have been emitted at a time at least half way between the beginning of the expansion and the present time. But in the shell material's reference frame, hardly any time would have passed since the beginning of the expansion, because it is moving so rapidly relative to you. Therefore, the conditions under which the light was emitted would have been those of the very early universe.

Note that this argument does not rely on general relativity, only special relativity. For the real universe, general relativity does come into play, but the answer to your question would still be analogous to what I've outlined here.

(To my thumbs-downer: So what's your answer?)

Answer 3

Light & matter did not exist until some time after the Big Bang.

Answer 4

On the contrary, observations indicate that universe is (at least was) expanding at speeds close to the speed of light.

The highest redshifts of quasars are about z~7.
Redshift of relict microwave rediation is z~1089.
The later corresponsds to rate of expansion v/c = 0.999,999

Answer 5

Inflation

A short (as yet unexplained) period of the very early universe where it seems the universe expanded much faster than the speed of light

Answer 6

Most light emitting bodies such as stars and galaxies have lifespans of billions of years, it may have taken billions of years for the light from to reach us, but once it has we see the light for billions of years.