Energy, etc

[Jim Green <JMGreen@SISNA.COM>]

Let me please chime in here,  Leigh and I are very close in this -- we may
quibble re wording but.....

Bill-

> I don't quite understand.  Here's where my brain-fuzz is located:
>
> In a short pulse of laser light, energy is located in the propagating EM
> radiation, OK?

NO. "Energy" is not "located"  It does not "flow".  It is not like water,
as Leigh says.  Energy is a property of a system.  You would not say that
the "blue" of a blue object is "located" anywhere would you?  Not a perfect
analogy (none are) but close.

Most of our physics language is only to say enough about a system to make
some sort of calculation and from there some sort of useful
prediction.  Physics has long since stopped trying to describe reality --
at least precisely.

The danger I have tried to mention here is that we often come to think of
our language as some sort of reality --- this because we use phrases
frequently enough that we forget to think just what it is we are saying --
like some sort of mantra.  Our misuse of the language may suffice at times,
but we come to assume that the faulty language is _always_ helpful.

It is not.  And this fact rears is head when we launch into some esoteric
discussion without clearly thinking through what we are saying,

Jim

Jim Green
mailto:JMGreen@sisna.com
http://users.sisna.com/jmgreen