Paul E Condon wrote: >Gary Turner wrote: > >>John Hasler wrote: >> >>>Pigeon writes: >>> >>>>It would be under tension, because the upper station is outside the >>>>geosynchronous orbit. So the bit above the break would fly off into >>>>space, and the lower bit would fall back. >>>> >>>The tension would taper from nominally zero at the base to maximum at the >>>attachment to the counterweight. >> >>Actually, maximum tension occurs at the CG, with minimums at the ends. >>Forces are reversed, maximum at the ends, and minimum (balanced) at the >>CG. These are tidal forces. A single point counter-weight, as opposed >>to distributed, will cause a discontinuity in the function, but the >>function holds true on either side of the break. >> >Center of gravity (CG) is of doubtful value in thinking about this >problem. The object extends over a region in which substantially >different gravitational accelerations occur, and is at rest in a >reference frame in which there is significant centrifugal force.
More correctly, center of mass. But the effect is the same. > >The rules of the space elevator game, as I understand them, are >1 a vertical tension member >2 mass at upper end is at higher altitude than geostationary orbit >3 mass at lower end is close to the surface of the Earth >4 the whole thing is stationary with respect to the Earth as a reference >frame. > >5 Adjust unspecified parameters so that it stays put without very large >rockets or other cheats. This tidal dependent structure is inherently stable. Some kind of accommodations will likely be needed. Atmospheric conditions can exhibit tremendous lateral forces. > >These conditions imply that maximum tension is at geosychronous orbit >altitude. Below that altitude tension is increasing with altitude. Above >that altitude tension is decreasing with increase in altitude. For an interesting application of these principles, read Larry Niven's "The Integral Trees". -- gt [EMAIL PROTECTED] If someone tells you--- "I have a sense of humor, but that's not funny." ---they don't. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]