On Mon, 7 Jul 2003 18:45:12 +0000 (UTC), Gregory L. Hansen wrote:
In article ,
Laurel Amberdine wrote:

snip
Ignorance time: people are saying "to first (second, zeroth) order" etc,
quite often lately. What does it mean, anyway?

If you have some function f(x), perhaps an unknown that you're trying to
solve equations of motion to find, it's often possible to approximate it
and wind up with a polynomial expansion. So you might get

f(x) ~= a + bx + cx^2 + ...

First order would be linear in x, second order would be quadratic in x,
etc.

Okay, thanks! It sounded familiar but I couldn't recall enough to piece a
meaning together.

In this particular discussion, I don't think "first order" really means
anything, it's just something that people are saying.

I don't know if the phrase is being used technically now or not, but it
does seem to have nearly become slang.


-Laurel