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A comment on Vacuum has friction from an effect similar to the Casimir effect. Parent comment

Re:Vacuum has friction from an effect similar to the Casimir... by geuis on Saturday February 12, 2011 @03:13AM (#2209646)
In physics, "temperature" is the same thing as "speed". The faster the movement of particles in a given amount of space, the "hotter" it is. The terms are interchangeable.

There is also a common misconception that you would freeze almost instantly if you jumped out of an airlock in space. Quite the contrary. A vacuum is actually an incredibly efficient insulator. Hence vacuum thermoses. Your body would not lose heat very fast. Not having a helmet on, though, would be very bad for your health.

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Re:Vacuum has friction from an effect similar to the Casimir... by wazoox on Saturday February 12, 2011 @05:55AM (#2209806)
> Not having a helmet on, though, would be very bad for your health.>

NASA accidentally tested it in 1966: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.h...

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Re:Vacuum has friction from an effect similar to the Casimir... by TeMPOraL on Saturday February 12, 2011 @01:00PM (#2210582)
This link just shown me how many misconceptions I have about vacuum exposure. Thank you! I've learned a lot from it.
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Re:Vacuum has friction from an effect similar to the Casimir... by Nick_C on Saturday February 12, 2011 @10:51PM (#2211981)
> Common misconception... a vacuum is actually an incredibly efficient insulator

Yes, it is even a very real problem for EVAs and spacecraft. One of the first things the Shuttle does is open up its radiators to help get rid of its internal heat. The astronauts doing EVA have a problem with heat too, they have to wear an internal cooling suit with fluid piped around their bodies.

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Re:Vacuum has friction from an effect similar to the Casimir... by harshpotatoes on Saturday February 12, 2011 @10:17AM (#2210133)
The speed in your definition would refer to the temperature of the particle, and not the temperature of the vacuum. This paper has both the vacuum and the particle not in thermal equilibrium, so the temperature of the vacuum is not due to the speed of the particle moving within it.

You can also have temperature from a photon flux.

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