Universe Expansion: How Fast Is It?

[Chris_Gottschal]

How fast is the universe expanding. Even an estimate would be a good enough answer.

 

[chroot]

Roughly 70 kilometers per second per megaparsec of distance.

http://en.wikipedia.org/wiki/Hubble_constant

- Warren

 

[marcus]

Roughly 70 kilometers per second per megaparsec of distance.

http://en.wikipedia.org/wiki/Hubble_constant

- Warren

another way to visulize it is as a percentage expansion over time.

at the present rate of expansion it would take about 14 million years for it to expand by a tenth of a percent-----or 140 million years to expand by one percent.

this is equivalent to what Chroot said

another way to say the same thing is that a galaxy which is at this moment 14 billion LY from us is receding from us at speed c.

a galaxy which is currently 28 billion LY from us is receding at speed 2c, and so on.

something 42 billion LY away is presently receding at 3c...

(this is just translating Chroot's figure into different units which may be more familiar to some people)