Date: Wed Feb 14 10:26:52 2007

Author: Paul Doherty

Subject: Re: Incandescent Bulb Destruction and Uses

Post:

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Hi Don


I do a laser speckle experiment with frosted bulbs.
Just mount the bulb and the laser shine the laser into the bulb and
look at the laser speckle.

http://www.exo.net/~pauld/summer_institute/summer_day1perception/
laser_speckle.html

I also shine a flashlight onto the bulb and show that you cannot see
the shadow of the filament.
But if you shine a laser onto the bulb you can see the shadow of the
filament.
A cool simple physics puzzle.

(In the above web page look near the bottom for "X-ray vision"

You can use an oil spot photometer to compare the brightness of a 60
watt incandescent bulb to a "60 watt" light output equivalent
fluorescent bulb, then measure the current draw to calculate the
power used, the fluorescent will use /1/4 the power.

http://www.exo.net/~pauld/summer_institute/summer_day1perception/
SolarBrightness.html

and it is fun to break the glass off and put the bulb on a Variac,
slowly turn up the Variac. The filament will glow red at first then
orange and yellow and then will rapidly oxidize.

Paul Doherty

On Feb 14, 2007, at 6:35 AM, Don Cameron wrote:

> I have two related questions. I have been replacing my
> incandescent bulbs with CFLs and not waiting until the bulbs burn
> out. As a result I have about a dozen various incandescent bulbs
> for which I have no good use. Rather then give them away or sell
> them, and have their energy use contribute to global warming...I
> was wondering if there are any good demonstrations or labs that
> safely destroy these bulbs that I could use over time.
>
> Secondly, is there a searchable archive of this list, and if so
> where is it kept?
>
> Sincerely,
> Don B. Cameron
> Physics / Chemistry / Earth / Fitness
> University of Denver H.S.
> 2393 South York St.
> Denver, CO 80208
> dcameron@du.edu
>


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I do a laser speckle =
experiment with frosted bulbs.Just mount the bulb and the =
laser shine the laser into the bulb and look at the laser =
speckle.http://www.exo.net/~pauld/summer_institute/summer_day1p=
erception/laser_speckle.htmlI also shine a flashlight =
onto the bulb and show that you cannot see the shadow of the =
filament.But if you shine a laser onto the bulb you can see =
the shadow of the filament.A cool simple physics =
puzzle.(In =
the above web page look near the bottom for "X-ray vision"You can use an oil spot =
photometer to compare the brightness of a 60 watt incandescent bulb to a =
"60 watt" light output equivalent fluorescent bulb, then measure the =
current draw to calculate the power used, the fluorescent will use /1/4 =
the power.http://www.exo.net/~pauld/summer_institute/summer_day=
1perception/SolarBrightness.htmland it is fun to break the =
glass off and put the bulb on a Variac, slowly turn up the Variac. The =
filament will glow red at first then orange and yellow and then will =
rapidly oxidize.Paul =
DohertyOn Feb 14, 2007, at 6:35 AM, Don Cameron =
wrote: I have two related questions.=A0 I have been =
replacing my incandescent bulbs with CFLs and not waiting until the =
bulbs burn out.=A0 As a result I have about a dozen various incandescent =
bulbs for which I have no good use.=A0 Rather then give them away or =
sell them, and have their energy use contribute to global warming...I =
was wondering if there are any good demonstrations or labs=A0that safely =
destroy these bulbs that I could use over time. =
=A0 Secondly, =
is there=A0a searchable archive of this list, and if so where is it =
kept? =A0 Sincerely, Don B. =
Cameron Physics / Chemistry / Earth / Fitness University of Denver =
H.S. 2393=
South York St. Denver, CO 80208 dcameron@du.edu =
=A0=

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