On Sat, Aug 17, 2013 at 3:38 AM, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: > On Fri, 16 Aug 2013 05:27:49 +0000, Dave Angel wrote: > >> 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. > > Is that based on the speed of light in a vacuum, speed of light in > copper, speed of electron drift in copper, speed of sound in copper? Or > perhaps it was aluminium wire? :-) > >> 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. > > I think a simple analogy that works is: the width of a single human hair > is a billionth of 100 metres (or yards, for Americans). People can > visualise 100 metres, and they can visualise a hair.
Further information here: http://en.wikipedia.org/wiki/Grace_Hopper#Anecdotes It was specifically looking at satellite comms, and it's the speed of light through a vacuum (the ideal maximum speed of satellite communication signals). Check the Wiki page's footnotes for reliable references. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
