[ExI] The L5 Society ( was: EP and Peak oil.)

John K Clark jonkc at att.net
Wed Apr 9 17:37:37 UTC 2008

"hkhenson" <hkhenson at rogers.com>

> Rubber has a dialectic strength of around 500 volts/mil, and a density
> close to water.  [.]So as a rough estimate, the cable mass to hold up 100
> km of rubber insulation alone would be in the range of 2 million tons.

OK, so forget rubber, let's try something that can do a little bit better
than 500 volts/mil, something like Fused Quartz, it can do
5 x 107 volts/mil. Yes Quartz is about twice as dense as rubber,
but even so that should reduce the weight by a factor of 50,000 or so.

And I'm not saying a space elevator will ever be built, I'm just saying
that if one can be made then there is no reason not to use it to carry
power lines.

> He  might have been willing to consider Peter's fantastic vision
>[power satellites] , but Gerry [O'Neill] had shown that another
> fantasy, lunar industrialization, was a  prerequisite.

It currently costs about $20,000 to put one kilogram into geosynchronous
orbit, and no I can't give you a number, I don't know how much a power
satellite would weigh except that it would be many many kilograms. It
seems to me that for the idea to be practical a dramatically cheaper way
needs to be found to put massive things in that orbit, and the only two 
ways I know of are space elevators or lunar industrialization. If neither
of those can work then power satellites are Dead On Arrival.

You would know better than me but I was under the (perhaps incorrect)
impression that the L5 society was set up to promote ideas like O'Neill's.
And by the way you never should have changed the name, the L5 society
sounded cool.

  John K Clark

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