4 ms·

I’m confused as to how they are still able to see back 13 billion years. I thought all the light from the original Big Bang has already passed us.

• baq 5y ago
  Space is expanding faster than the speed of light. This means we’ll be able to see the same time in the past, just from further and further away.
  • ziotom78 5y ago
    This is true regardless of expansion, the important thing is that the space be infinite.
    • layer8 5y ago
      If space is finite (i.e. is a four-dimensional sphere), the same light will continue passing us again and again (just fainter and fainter).
• layer8 5y ago
  The big bang didn’t happen at any particular location. It happened everywhere all at once. Thus light from the big bang (or rather, what’s currently the cosmic microwave background) will continue passing us for all eternity. (That is, until the EM waves become stretched too long due to cosmological redshift.)