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Old May 29th 04, 01:49 PM
sanman
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Default JP Aerospace and rotating sun toy

(Vincent Cate) wrote in message . com...
I note that the first airship pictured at:

http://www.hobbyspace.com/AAdmin/arc...alAirship.html

it looks like a dark blue in the front part of the V and then silver
in the 2 back parts. On my shelf next to my desk I have one of
these toys that spins in sunlight. Probably most people are
familiar with it, there are 4 little plates that are black on
one side and white on the other that spin in a glass bulb with
a partial vacuum. So I wondered if this is related to the JP Aerospace
propulsion system. My toy moves away from the black side.
Basically molecules bounce away faster from the hotter black
side and so push on it more.

But this would push the airship backwards as it is colored now.
So this does not seem to be it, unless the builder got things
backwards.

Still, this force seems like it could be some fun for airships
at high altitudes. Imagine a single cylinder shaped airship
that is black in the back half and white in the front half,
with something inside separating the two halves.
Imagine that it is moving perpendicular to the sun and rolling
like a rotisserie to even out the heat. So the back half
that is black would be hotter and would have a net thrust.
Anyone know how to calculate this thrust?

-- Vince


Would there be any way to create a "nano-radiometric" effect, by
covering the surface of an object (eg. airship) with many nano-sized
radiometric structures?
Suppose you had a surface covered in a nano-sized sawtooth pattern,
with the front slope of each sawtooth reflecting more light and the
vertical backside of each sawtooth that absorbed more light. Could
this generate a net thrust in the rearward direction, to propel an
object forward? Comments?