[570782@gmail.com (OP)]

How we can get ahead of the light from the early formation of the Universe to allow the new telescope to see it. I would have thought it would have passed us by a long time ago. Light presumably travels in a straight line.

[Halc]

How we can get ahead of the light from the early formation of the Universe to allow the new telescope to see it.

The oldest light we see today was from the recombination event when the universe was about 380,000 years old. Before this 'early formation', any light emitted quickly hit something since the universe was not yet transparent.

I would have thought it would have passed us by a long time ago. Light presumably travels in a straight line.

The light that was emitted closer by already has, yes, but since it was emitted from literally everywhere, there are plenty of places from which light is reaching us only just now. The CMBR (cosmic microwave background radiation) light we see today was emitted by material which is currently about 42 billion light years away (as measured in comoving coordinates). The light we see tomorrow was emitted by material which will be a bit over 4 light days further away tomorrow. That's approximately the current rate of growth of the size of the visible universe. There's plenty of material even further away than that, so we'll always be seeing ever cooler CMB light.

The material that is currently 46 billion light years away was much closer by than that when the universe was only 379,000 years old, so it didn't travel 46 billion light years to get to us.

[evan_au]

See: https://en.wikipedia.org/wiki/Cosmic_microwave_background
Light cannot reach us from any earlier than this point about 400,000 years after the big bang, as the universe was a plasma (like the surface of the Sun), which is opaque to electromagnetic radiation..

But some scientists are hoping to detect other forms of radiation from the early universe:
- Neutrinos would have been formed during the production of Deuterium and Helium in the first few seconds of the early universe.
- Gravitational waves would have presumably been formed during the earliest moments of the universe
- Both of these would now have much lower energy due to the expansion of the universe, and so be much harder to detect, but some researchers are hoping to find a way...