Date: Mon, 25 Sep 2000 12:00:23 -0500

Author: brian whatcott

Subject: Re: Totally evacuated radiometer source?


Interesting question. The effect is many orders smaller than the
thermal effect in Crookes radiometer. And the thermal effect
persists to quite low vacuum.
So it would need a very intense light and/or a very low
resistance pivot and a very high vacuum.

Brian Whatcott

At 12:22 9/25/00 -0400, you wrote:
>Can you do that? In a lecture-demonstration apparatus?
>Dick Berg
>On Mon, 25 Sep 2000, Starke, Cheryl wrote:
>> Hello all,
>> does anyone know where to purchase a totally evacuated radiometer? This is
>> where the vanes spin because of the photons being reflected from shiny side
>> (which is in the opposite direction of the partially evacuated radiometers
>> where the vanes spin because of the black side heating and expanding the
>> next to them quicker). I've only been able to find the partially evacuated
>> radiometers listed in the catalogs I have.
>> Thank you.
>> Cheryl Starke, Physics Lab Coordinator
>> Montgomery College
>> 51 Mannakee Street
>> Rockville, MD 20850
>> Telephone: 301-279-5239
brian whatcott Altus OK