Re: Light bulbs

[Stefan Jeglinski <jeglin@4PI.COM>]

> Put a bulb (either burned out or not) base down in a cup of water and
> put it on the turntable in your microwave oven. Set it for 15 seconds
> or so and watch it 'light up' as it passes through the 'hot spots' in
> the oven.


OK, I tried this and found it rather amusing. What's going on here?


I surmise that the filament absorbs microwaves to the extent that it
glows as it would when current is passed through it. My only point
would be that since microwaves would not appreciably penetrate the
metal of the filament, the power must be dissipated largely as a
transient surface current. Clearly I could see moments when the
filament glowed brightly.

OTOH, I believe I also witnessed a transient low-pressure discharge
type of glow, but this I did not expect because I thought the
atmosphere in the light bulb was essentially inert (nitrogen). I
guess the tungsten vapor would be able to support the discharge
currents that appear to be present? Or other impurities?

Anybody know more about this? Is there more going on?



Stefan Jeglinski