If the universe is 13.8 billion years old, how can we see things 28 billion light-years from us? Doesn’t seem like there is enough time for the light to reach us.
In: 45
We can see things that are currently 28 billion light years away because they were closer than that when the light from them was emitted.
This is because the universe is expanding.
The Cosmic Microwave Background Radiation is the furthest thing we can see. The light from it has travelled 13.8 billion years (so it has travelled 13.8 billion light years) to get here. However, since that light left the universe has continued to expand and the further away that part of the universe is the faster it is expanding from us (this is the same for any two points in the universe). This means today where the CMBR was 13.8 billion years ago is now 46 billion light years away. However, when that light left it wasn’t 13.8 billion light years away, it was only millions of light years away. You really have to picture the universe as been expanding the entire time.
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