Re: Strange "Energy" Units

[Leigh Palmer <palmer@SFU.CA>]

> Is it not the common parlance of texts (eg., Optics) to refer to the
> transfer of energy per unit time across unit area of wavefront the
> "Intensity" of the wave?
>
> IOW, and more generally,  the "density" of a "flowing" item becomes an
> "intensity" - this seems to be common language.

"Intensity" is a common misnomer. The correct radiometric term is
"radiant flux density", and it also exists in two more flavors
depending on context:

"Radiant exitance" is the power emitted per unit area of a source

"Irradiance" is the power falling on a unit area of a target

Note that the term "wavefront" used above implies a special sort
of collimated radiation.

Elementary textbook authors nowadays seem to be ignorant of this
standard nomenclature which can be found in any good optics text.

Leigh