Q&A: Physics, the Big Bang.
Originally published:
This is an English translation (via GPT-5.4). Read the original Hebrew version.
Physics, the Big Bang.
Question
As I understand it, it is commonly said that the universe has been expanding since the Big Bang. Not that matter is expanding into a vacuum, but that space itself is increasing.
If I understand correctly, that is because the galaxies are moving away from one another.
What I don’t understand is: why not claim that matter is expanding within the vacuum? I hope the question is clear.
Answer
That is not the same thing. The measurements show that space itself is inflating.