jwm@stdc.jhuapl.edu (James W. Meritt) (04/13/88)
In article <1033@daisy.UUCP> wooding@daisy.UUCP (Mike Wooding) writes: }In article <1840@ssc-vax.UUCP>, eder@ssc-vax.UUCP (Dani Eder) writes: }> In fact, if there is not enough time to run all our power }> plants backwards to get the CO2 out of the atmosphere before we }> fry, intentionally placing mirrors in orbit to deflect inco iming }> sunlight might give us more time to solve the problem. } Might be easier to make a cloud (of dust?) for a little shade } on a hot day. Wouldn't stay around a long time, but then that } could be an advantage. Gets noticeably cooler during an eclipse } which lasts only minutes. Were talking a LOT of dust though, } more than might be reasonable to lift from earth, but there's } the moon. And with a mass launcher, and maybe some static } charge to disperse, ... well you get the idea? Could it be } kept from falling to earth? Would it matter if it did? Not being much of an astrophysicist, could someone comment on putting dust in an orbit between the earth and the sun? The position I have in mind is an orbit closer to the sun at the point where the earth's gravity balances the suns to the extent that it could orbit at the (slower) speed that the earth does. It sounds to me like it would orbit properly, but I have no idea how far from the earth this point is, nor does it seem overly stable. Could a, say, 5% reduction in incoming solar flux be achieved in this way (balancing the "extra" beamed in from those billions and billions of SPSs ;~))? Disclaimer: Individuals have opinions, organizations have policy. Therefore, these opinions are mine and not any organizations! Q.E.D. jwm@aplvax.jhuapl.edu 128.244.65.5
jfc@athena.mit.edu (John F Carr) (04/14/88)
In article <226@aplcomm.UUCP> jwm@stdc.jhuapl.edu.UUCP (James W. Meritt) writes:
: Not being much of an astrophysicist, could someone comment on putting
: dust in an orbit between the earth and the sun? The position I have in
: mind is an orbit closer to the sun at the point where the earth's
: gravity balances the suns to the extent that it could orbit at the
: (slower) speed that the earth does. It sounds to me like it would orbit
: properly, but I have no idea how far from the earth this point is, nor
: does it seem overly stable.
The point of which you are thinking, one of the Lagrange points, is
not stable. An object placed there will drift away.
John Carr "No one wants to make a terrible choice
jfc@athena.mit.edu On the price of being free" -- Neil Peartmarkey@tybalt.caltech.edu (Ron A Markey) (04/14/88)
In article <226@aplcomm.UUCP> jwm@stdc.jhuapl.edu.UUCP (James W. Meritt) writes: >Not being much of an astrophysicist, could someone comment on putting >dust in an orbit between the earth and the sun? The position I have in >mind is an orbit closer to the sun at the point where the earth's >gravity balances the suns to the extent that it could orbit at the >(slower) speed that the earth does. It sounds to me like it would orbit >properly, but I have no idea how far from the earth this point is, nor >does it seem overly stable. Could a, say, 5% reduction in incoming >solar flux be achieved in this way (balancing the "extra" beamed in >from those billions and billions of SPSs ;~))? > > >Disclaimer: Individuals have opinions, organizations have policy. > Therefore, these opinions are mine and not any organizations! >Q.E.D. >jwm@aplvax.jhuapl.edu 128.244.65.5 The distance from the Earth to the center of mass of the cloud works out to be about 1,530,000 km. Given that the moon is out there swinging around 400,000 km, I don't think that it would be to awfully stable. I anyone is interested in the math, send me mail and I'll give it to you. Another problem with this pops to mind. This dust is not just going to block the sunlight, it is going to absorb and re-radiate it. Given that the cloud is going to spread out (it would even if the moon weren't screwing things up) and potentially occupy a lot of sky it seems likely that it will eventually end up contributing to the problem that it is supposed to solve by absorbing a LOT of energy and radiating it at Earth. - Ron (markey@tybalt.caltech.edu)