heh heh, my physics
teachers in high school hated when I used this phrase. But it's useful
, as well as being good for a quick laugh
, if you're around the right sort of people. I guess the only way to explain its use would be to give an example. Say you had a uniform distribution of charge covering a flat wall. Say you wanted to find the force on an electron 1 cm from that wall. The exact
(but clearly wrong) way to do this is to integrate
the electric field across the entire wall. The less exact
, but much, much easier method (and therefore the Right Thing
to do) is to say, hey, the wall is approximately infinite, so we can use the formula for E of an infinite sheet. Ain't that cool?
And to Kung: Approximately infinite just sounds better than effectively infinite, wouldn't you agree?