Quote:
Originally Posted by AstralTraveller
I once discovered what happens when one puts too much liquid nitrogen in a nice (expensive) agate mortar and pestle. We did manage to glue it together but I never tried that trick again.
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Hi David,
A close friend and fellow engineer has worked for a major observatory for about the
past 27 years. He likes to tell me the story about the time back in the early 80's
when the observatory procured a new infrared sensitive CCD.
Anyway, this particular CCD was the same model as that used by the US spy satellites
for detecting the heat plumes of Soviet ICBM's. The Cold War was still in
full swing and suffice to say, procuring such sensitive military technology required
US DoD export approvals including signatures by officials up to the
ministerial level. Costing a sizable chunk of the observatories annual budget,
an American from a large US defense contractor flies out of the US with this
state-of-the-art CCD in his brief case basically hand-cuffed to his wrist lest it fall
into the hands of the Reds.
When it arrived at the observatory, the CCD was carefully mounted on a substrate
and then it was cooled down with liquid nitrogen. That's when things went awry.
The differential contraction of the CCD compared to the substrate it was mounted on
caused the incredibly expensive CCD to crack. There was nothing to do but to
ask the man with the brief case whether he could please fly back to America and
bring them another.
holy crap thats cold 
