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To: Mr. K

Maybe at the time scales involved, the power module (nuclear, which was assisted by photocells when the craft was near the sun, but no more) will have long petered out before directional emission of infrared photons could significantly slow the craft let alone stop it.

I’m cudgeling my brain without success to remember the name of the little physics toy that had an assembly of two to four vanes, painted white on one side and black on the other, mounted to pivot in a nearly evacuated glass bulb. Sunlight would make the vane assembly turn as the black side of the vanes became warmer than the white side. And yet it wasn’t light pressure that achieved this, but differential between how the residual gas in the bulb was warmed and set in motion at the surfaces of the vanes.


35 posted on 07/24/2012 11:32:29 AM PDT by HiTech RedNeck (let me ABOs run loose, lew (or is that lou?))
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To: HiTech RedNeck
I’m cudgeling my brain without success to remember the name of the little physics toy that had an assembly of two to four vanes, painted white on one side and black on the other,

That's a Radiometer.

39 posted on 07/24/2012 11:57:15 AM PDT by ArrogantBustard (Western Civilization is Aborting, Buggering, and Contracepting itself out of existence.)
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To: HiTech RedNeck; Mr. K
And yet it wasn’t light pressure that achieved this, but differential between how the residual gas in the bulb was warmed and set in motion at the surfaces of the vanes.

Or... the white surface reflected 'light', and the black surface absorbed light. In a sense, repulsion and attraction. The gas near the white surface would tend to expand due to the additional 'reflected heat', adding 'repulsion' to the mix.

Maybe it's a combination of things, instead of one thing.

45 posted on 07/24/2012 7:00:26 PM PDT by UCANSEE2 (Lame and ill-informed post)
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