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

Author: brian whatcott

Subject: Re: Totally evacuated radiometer source?

Post:

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
air
>> 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
Eureka!

Back