Hacker News new | past | comments | ask | show | jobs | submit login

> inversely proportional to the square of the distance between them

As I understand it, that’s an approximation for Euclidean space because the area of a sphere is also proportional to the square of the radius in such a space, but it’s not true of non-Euclidean spaces like in GR because the area-radius relation is different.

IIRC, the cosmic microwave background has a gamma factor of about 1100, so the area of that shell is the same as one 1100 times closer or 1/1100^2 times the area as a Euclidean sphere with that radius.

> And since we know that gravity affects the rate of flow of time, wouldn’t the rate of time be enormously distorted earlier universe?

Time did indeed slow down then compared to now, although it’s not entirely obvious to me that this has any physical interpretation when it happens “everywhere”: https://youtu.be/66V4RSmDqYM




My understanding is that time was not slower (whatever that would mean), only that the expansion of the universe means that light is stretched. So events in the early universe appear to happen 5 times slower.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: