Designing SPS to accommodate tidal forces (was Nuke vs. SPS)

--- In spacesettlers@yahoogroups.com, "hitssquad" wrote:
>
> --- In spacesettlers@yahoogroups.com, "brooksn" wrote:
> > --- In spacesettlers@yahoogroups.com, "hitssquad" wrote:
> > > A dirty secret of SPS is that its cost varies minimally with launch cost. Assume launch cost is $100/kg, and show us on paper a plan for building SPS in GEO at an overnight cost of less than a quadrillion dollars per gigawatt.
> > Where are you getting your numbers from?
>
> The ISS has a capacity of 100 kilowatts and cost $100 billion, despite its only being in LEO, not transmitting its power, and not being large enough to be affected by tidal forces.

Is that a joke? The purpose of the ISS, a research laboratory in orbit built to house astronauts, and the purpose of an SPS platform, to collect and transmit power, are not the same, so why would you use the ISS to calculate the cost of SPS?

> > > > c) the alternatives are are not priced according to their full cost
> > > Is that falsifiable, and do you have a plan for changing that even if it were true?
> > Pollution has a cost
>
> CO2 isn't a pollutant (as its increasing abundance in the atmosphere provides net benefits to humanity). Nuclear doesn't produce CO2, regardless.

The scientific community and the science disagrees. Nuclear power plants are already the most expensive power source to build.

> > A carbon tax [...] is used by almost 2 dozen countries
>
> It isn't used by China or India, it isn't high enough to make a market case for SPS, and it doesn't affect nuclear.

It is used in India, do you ever get tired of being wrong? No one is arguing that it is 'currently' high enough for SPS, your question was, 'do you have plan?'
http://en.wikipedia.org/wiki/Carbon_tax#India
On nuclear, see above.

> > > Earth-orbit-SPS [suffers from] the tidal-force problem
> > Only if the structure is one solid piece, if it is in sections that can move away from each other and then closer during rotation
>
> What does that mean?

Imagine a huge one piece SPS, if tidal forces are a problem, then the structure would experience stresses during orbit. Now imagine the SPS is in many many pieces instead and connected by overlapping metal bars that allow movement with motors and ball bearings. That way tidal forces could 'pull' them a apart, (possibly even allowing that energy to be tapped), then when the orbit was not during a period of tidal stress the motors could reverse and pull them closer.
Brooks