Re: Threading a moon

Eivind Kjorstad wrote:

Yeah. But I can't imagine it's that impressive. Making copper-bars with
lasers on them will consume energy, as will launching them from Callisto.

Escape-velocity from jupiter is 60km/s or so, so at best, the energy
released is the same as the energy required to accelerate the
copper-bars to 60km/s. Minus the energy used for mining, transporting,
refining etc the copper. Minus the energy for making and installing the
laser. Times the efficiency of the laser and receiver.

60 km/s is a massic energy of 1.8 GJ/kg, which isn't anything to cough at.

*Certainly* doesn't sound anything at all like "huge amounts of
near-free energy".

Depends on your definition of "free," I suppose, and I haven't seen anyone else in this thread use this phrase you've mentioned in quotes, so I'm not sure whose argument you're actually trying to refute.

The energy released (even taking into account more realistic energy estimates and efficiencies) exceeds the energy you have to put in, that's for sure. Whether that's worth your use of copper is another question.

--
Erik Max Francis && max@xxxxxxxxxxx && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM, Y!M erikmaxfrancis
You'll learn / Life is worth it / Watch the tables turn
-- TLC
.

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