On 2012-06-27, Jon Elson wrote:
Tom Gardner wrote:


Eventually, fusion power will be the best solution until some new energy
source comes along, maybe antimatter. I wonder how the leftists will
take THAT! (If leftists still exist)
Fusion turns out to be a LOT harder than anybody thought.
Physicists have been saying it is 10 years away for 50+ years, now.
Tokamak looked promising until you understand the surface area to
volume relationship, then it becomes obvious you can't have a thread
of plasma many meters long at 10 megaKelvins, all the heat leaks away.

The only hope is a VERY compact plasma, and that is a hard state to
maintain. And, the implosion devices are most likely to self destruct
due to the massive thermal cycling. Not immediately, but it seems like
they would end up requiring huge amounts of maintenance.

One more thing about Fusion.

When we think about the Sun (powered by fusion), and how brightly it
shines, we conjure that fusion of the hot plasma of the sun produces
very intense energy per ton of weight.

This is actually NOT true.

Per ton of weight, Sun's core produces about as much power, as you
would get from a ton of compost in your backyard compost pile. Yes,
sure, the compost pile is warm and the energy is produced, but the
power density is miniscule -- no one can economically extract
electrical power from warm rotting compost.

i