Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: where was Big Bang

Learn more physics!

Most recent answer: 02/01/2020
Q:
Scientists claim we can see the universe at 300,000 years after the big bang (further can not be reached for particles hadn't yet "organized" themselves to be seen─a sort of a wall hinders going back to the precise moment of creation). My question is, since the universe is in continuous expansion (and in acceleration too), how can the location of the big bang be known to be able to focus on it with the telescopes (I had in mind the Hubble telescope of course). The universe and astronomy is my passion and has been so for the last 40 and more years. Regards
- Andy (age 78)
Varese, Italy
A:

The Big Bang was everywhere, not just some particular location in our space. So the cosmic microwave background is seem by looking out in any direction. Even in unconventional theories (brane collisions...) the special starting condition was everywhere.

The "organization" you mention was nothing exotic. It's just that protons and electrons, the main ordinary matter constituents of our universe, form an opaque plasma when they're hot. So you can't use light to see into that regime. Once they cooled down, they mostly combined into hydrogen atoms, which form a transparent gas, allowing light to travel through it. 

Mike W.


(published on 02/01/2020)

Follow-up on this answer.