Up, up and away?

This really is interesting and has remarkable implications. From the
sub-micro to the macro:

http://www.bbc.co.uk/news/science-environment-11927793

Light pressure could also be responsible for cloud movement. Here, and
"up there".

Chris.B:

This really is interesting and has remarkable implications. From the
sub-micro to the macro:

http://www.bbc.co.uk/news/science-environment-11927793

Light pressure could also be responsible for cloud movement. Here, and
"up there".

Is radiation pressure from light a newly discovered phenomenon? I don't
know--just asking--but it seems like I read about this maybe 60 years
ago....

Davoud

--
I agree with almost everything that you have said and almost everything that
you will say in your entire life.

usenet *at* davidillig dawt cawm

On Dec 8, 9:01*pm, Davoud wrote:

Is radiation pressure from light a newly discovered phenomenon? I don't
know--just asking--but it seems like I read about this maybe 60 years
ago....


Nope, it's not new. Most of us have had "lightbulb" radiometers with
little black and white vanes whirring around.

I believe it is the use of lightofoils which have never been tried
before.

On 2010-12-08, Chris.B wrote:
On Dec 8, 9:01*pm, Davoud wrote:

Is radiation pressure from light a newly discovered phenomenon? I don't
know--just asking--but it seems like I read about this maybe 60 years
ago....


Nope, it's not new. Most of us have had "lightbulb" radiometers with
little black and white vanes whirring around.

I believe it is the use of lightofoils which have never been tried
before.

Crookes radiometers don't use radiation pressure, though. The black
surfaces absorb radiant energy and warm the thin air inside the bulb by
convection. That produces the thrust that spins the paddles. One made
with a high vacuum won't spin.

Radiation pressure has been known since the days of Maxwell.

Bud

In sci.astro.amateur message , Wed, 8
Dec 2010 15:01:23, Davoud posted:

Is radiation pressure from light a newly discovered phenomenon? I don't
know--just asking--but it seems like I read about this maybe 60 years
ago....

http://en.wikipedia.org/wiki/Nichols_radiometer
http://en.wikipedia.org/wiki/Radiation_pressure 1871 / 1900.

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Web http://www.merlyn.demon.co.uk/ - FAQish topics, acronyms, and links.
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So much for theory. Thank you both for confirmation of the modus
operandi of the common, radiometer, scientific toy. Interestingly (?)
the laser shaped projectile lift research uses the same principle of
heating rather than direct radiation pressure.

Going back to the original optical "lift" story It seems that light
affects the physical behaviour of all suspended particles. Though the
effect is so small as to be completely swamped by other environmental
effects. Requiring a closed apparatus, a controlled environment and a
powerful laser to show direct particle movement due to the radiation
pressure of light. So my attempts to use a laser pointer to "bore
holes" in the suspended vapour cloud above the kettle is doomed to
abject failure. :-)