Re: brightness vrs. power

["Bernard G. Cleyet & Nancy Ann Seese" <georgeann@REDSHIFT.COM>]

Try looking at the filament with a hand held spectroscope.  Use a Halo-Si lamp for a
greater range.  (typical demo. for astronomy ,and Physics, students.)

more later.

bc

Barlow Newbolt wrote:

> I think that your reasoning is perfect.  It is not true that the
> brightness of a light bulb is a linear function of the power level in
> the operating filament.  You have to worry abou the spectrum of a
> thermal radiator.  It may or may not be approximately a black-body
> spectrum but that would be a good place to start.
>
> In proof you might consider reducing the current in the filament until
> no visible light is emitted.  Only infrared radiation is coming from the
> bulb, but the brightness is definitely zero.
>
> Barlow Newbolt
> Professor of Physics
> Washington and Lee University
> e-mail: newboltw@wlu.edu
> telephone:  540-463-8881
> fax:  540-463-8884
> Office: Howe 218
>
> "Had I been present at the creation,  I would have given
> some useful hints for the better ordering of the universe."
>
>           Alphonso X,  Learned King of Spain  (1252  - 1284)