3 ms·
> This isn't gravitational repulsion. It's why the universe is ~13.8 billion years old but we can see the light of objects that we now estimate to be >40 billio
by tommiegannert 4y ago
> This isn't gravitational repulsion. It's why the universe is ~13.8 billion years old but we can see the light of objects that we now estimate to be >40 billion light years away. Space itself has expanded. It's not gravitational repulsion.
To add:
Masses repelling and space expanding would have the same effect on the observable universe boundary: linear models break down.
However, light redshifting, where more distant objects are more redshifted, fits with expansion. That cannot be explained by gravity. (Whether it's expansion or some other mechanism is still unknown, AFAIU.)