On 11/2/2014 9:11 AM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:m35chg$mlv$1@dont-
email.me:

What would cause the superconductors to warm up? They have no
resistance, so it wouldn't be from internal means. And kept shaded,
there would be very little external heat applied.


Not much, maybe. I just figured that their state would not be stable, that it
would take very little, from any source, to heat them to the point where the
problem started getting rapidly worse. Maybe it wouldn't be an issue if the
superconductor were 'hot' enough. -196°C is 77°C above absolute zero, so
maybe some of them will always stay cold enough with nothing but shade.


Actually, high temperature superconductors have been found at
temperatures as high as -135C. And in the shade, space is very cold,
even at Earth's distance from the sun, shaded items are very cold. Even
the moon, which will hold some heat, cools to -233C at night time.

Heat sources might be unexpected though. If a thin wire got hit my a
micrometeorite, it would likely get stretched and heated pretty fast. So the
question might be what kind of margins exist for safe operation.


I think the odds of this happening between now and the end of the solar
system are pretty slim. If a small wire could so easily be hit by a
micrometeorite, our satellites, space stations, rockets, etc., all much
bigger, would be in deep doo-doo.

No, micrometeorites are not very big, but their velocity makes them very
dangerous. Energy increases with the square of the velocity, and
micrometeorites move very fast.

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Jerry Stuckle

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