So what number is this?
sq. rt. -93i
A brief biography with portrait.
This was highly non-obvious. After all, given a 1 litre bottle of pure helium gas and a 1 litre bottle of argon, you wouldn’t necessarily guess that both have the same number of atoms in them. Particularly since an argon atom is about ten times heavier than a helium one, and larger as well. Perhaps there are billions upon billions more atoms in one bottle than the other. But, in fact, they do have the same number in them. Avogadro’s Law basically says that similar bottles of gases always have the same number of molecules in them. (In the particular case of helium and argon, a molecule is just a single atom.)
If you know that a 1 litre bottle of gas always has the same number of molecules in it, that number’s a useful way of thinking about how many atoms there are. Technically, the number of molecules in a cubic centimeter of gas at a defined temperature and pressure is called Loschmidt’s number and it’s such that the number of them in that 1 litre bottle is 2.69 x 10[sup]22[/sup].
Avogadro’s number is closely related to this and works out as 6.022 x 10[sup]23[/sup]. The exact definition is a bit technical, but the underlying idea is the same. It’s important because a physicist or chemist looking at an everyday object and wondering how many atoms are in it will think “it’ll be roughly 10[sup]23[/sup] or so” as their first rough guess. Not 1000 or a Googol (1 followed by a 100 zeros). About Avogadro’s number of them.
Avogadro gets to have his name associated with the number because he was really the first to realise that there was such a single number that could be used in this way, though he didn’t know its numerical value.
[Odd way to lose my Pit virginity …]
I thought everyone knew what Avocado’s number is. It’s the number of avocados you can pile onto a burger before it tips over.
That number is 4.5.
…pi…on a planck…c’mon, this is good stuff…
Bingo.
When I’m in the h-bar I like to have a Planck on two pi(es).
culture, I’m going to assume that you meant to start this thread in MPSIMS. I’ll move it for you.
Cajun Man ~ SDMB Moderator
The problem with constants is that they’re really only ther to solve problems mathmatecians couldn’t solve and most of them aren’t terribly precise. The only good thing about them is that they work (jeez, talk about fighting two sides of an issue). As an engineer I’ve learned to appreciate them but not love them.
slight hijack here, but i must put forward my ‘all theoretical physicists are dirty old men’ theory. otherwise, why else would quarks have names like naked, bottom, and charm?
or maybe i’m just being dumb… :rolleyes:
incidentally, i like my pi on a planck, but i prefer it with philedelphia to quark. please stop me if i’m bohring you to death 
(sorry, i couldnt stop. they made me do it!)
There’s no such thing as a naked quark (actually I’m guesing a ‘naked’ quark is a reference to quark confinement, but it’s the first time I’ve heard them called ‘naked’), quarks, unlike the other fermions, are very prudish.
And a cup of Maxwell house…mmmmmm
Dang. Now I can’t curse the opposition in my post!
Anyway, you’all got them all. I guess that is no suprise.