Re: Filament resistance

[Leigh Palmer <palmer@sfu.ca>]

> This discussion has raised in my mind the following question that has
> occured to me before.
>
> The surface of the Sun is about 5800 K and emits spectrum of light that
> has a yellow cast.  The filment of a light bulb, if made of tungsten,
> could not be hotter than 3695 K, its melting point, and yet emits light
> that appears white, even in the small clear bulbs used to demonstrate
> series and parallel circuits.  The white light should indicate that the
> tungsten is at a higher temperature than the surface of the Sun.  What am
> I missing here?

You are a "victim" of the well-known (to psychologists) illusion of
"color constancy". Tungsten light (nearer 2850 C = 3125 K) is much
warmer than sunlight. To see this dramatically try exposing a frame
or two of your next roll of outdoor film indoors, under tungsten
illumination (no flash, no fluorescent, no window light). You will
be very surprised at the results. Photograph the same colored object
this way and in direct sunlight.

Leigh