as an ex moto-x'er myself maybe I was not clear.
How long after the BB I mean.
I read some numbers a while ago and can not remember where.
This is actually not homework.
An “I do not know” or “please clarify” is an acceptable answer.
Life?
With the present understanding of the age of the universe (acceleration and temperature), how long before the universe is cool enough to support our type of life?
And
If the Earth existed since the BB, how long would we see a red sky at night from the after glow of the big...
Light
Does the speed of a photon go to zero when it reflects of a mirror at a 90 degree angle? Just to be sure, I mean if the photons’ comes straight down on a mirror lying flat and reflects straight up, does the photon’s velocity reach zero at any point in time?
also
Particle...