On Friday 16 August 2013 10:27:36 Dave Angel did opine: > Roy Smith wrote: > > In article <520da6d1$0$30000$c3e8da3$54964...@news.astraweb.com>, > > > > Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: > >> On Thu, 15 Aug 2013 16:43:41 +0100, Chris Angelico wrote: > >> > A mole is as much a number (6e23) as the light year is a number > >> > (9.5e15). > >> > >> Not quite. A mole (abbreviation: mol) is a name for a specific > >> number, like couple (2) or dozen (12) or gross (144), only much > >> bigger: 6.02e23. And I can't believe I still remember that value :-) > > > > I remember it as 6.022e23 :-) > > > > In my high school chemistry class, there was a wooden cube, about 1/2 > > meter on a side, sitting on the lecture desk in the front of the room. > > The only writing on it was "6.022 x 10^23". It sat there all year. > > > > The volume of the cube was that of 1 mole of an ideal gas at STP. > > > >> A light-year, on the other hand, is a dimensional quantity. Whereas > >> mole is dimensionless, light-year has dimensions of Length, and > >> therefore the value depends on the units you measure in: > >> > >> 1 light-year: > >> > >> = 3.724697e+17 inches > >> = 0.30660139 parsec > >> = 9.4607305e+12 kilometres > > > > Hold your hands out in front of you, palms facing towards each other, > > one shoulder-width apart. That distance is about one > > light-nanosecond. > > Narrow shoulders. > > I figure it just under a foot. I once attended a lecture by Grace > Hopper where she handed out "nanoseconds," pieces of wire about a foot > long. She said that the beaurocrats were always asking how much is a > nanosecond, and couldn't imagine what a billionth was like. So she gave > them something physical.
Chuckle. I always figured Grace Hopper had to have been a stand up comic in some previous life. She sure could translate the problem into something the paper pushers could grok. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> Nachman's Rule: When it comes to foreign food, the less authentic the better. -- Gerald Nachman A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. -- http://mail.python.org/mailman/listinfo/python-list
