The speed of light (And all other streams of massles energy emission) propagates through a vacuum at 299,492,458 meters per second. Why does the universe choose this specific velocity? Why not a billion meters per second? Why not 55 MPH?

enolancooper

The best answer so far is: no particular reason.

There are several fundmental constants in the Universe, and they could conceivably have any value, though some values of some constants would lead to very short-lived Universes, or Universes where life wouldn’t be possible. We just lucked out–or looking at it from the other side of the coin, if our Universe wasn’t suitable for life, we wouldn’t be around to think about it anyway.

A slightly better answer is, the speed of light is 299,**7**92,458 meters per second. And the speed of light can be derived (like Maxwell did) from other constants, but that just shifts the question to why are those constants the values that they are.

Speed of light nuthin’, how the hell did Avogadro come up with that number? Sheesh.

Thanks for catching that typo. Some people out there really are paying attention.

enolancooper

eh. What’s another 300,000 meters per second?

I’m sorry I can’t help you with your original question, though. I mean, *really* sorry.

I can’t tell you who did come up with it, but the chem teacher just said today in lecture that all Avogadro came up with was his law (the only famous thing anyhow). It’s only called his number because it follows from his law.

I know you’re just kidding, but having learned about this recently, I too have wondered this. WTF? What did he do to come to this figure?

Avogadro’s number is defined as the number of atoms in *exactly* 12 grams of carbon-12. It provides a convenient way to convert between grams and atomic mass units.

Yeah, Avagadro’s number. Always comes up in casual conversation. "Hey Bill, did you know that if there was exactly 18 grams of water in that glass, there would be 602,000,000,000,000,000,000,000 molecules of water in there?

Yep, comes up all the time, I bet…