Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!mips!ptimtc!nntp-server.caltech.edu!sol1.gps.caltech.edu!CARL From: carl@sol1.gps.caltech.edu (Carl J Lydick) Newsgroups: sci.space Subject: Re: Beanstalk analysis reprise Message-ID: <1991Jun18.160904.15921@nntp-server.caltech.edu> Date: 18 Jun 91 16:09:04 GMT References: <43279@fmsrl7.UUCP> ,<43882@fmsrl7.UUCP> Sender: news@nntp-server.caltech.edu Reply-To: carl@sol1.gps.caltech.edu Organization: HST Wide Field/Planetary Camera Lines: 28 In article <43882@fmsrl7.UUCP>, wreck@fmsrl7.UUCP (Ron Carter) writes: >The terminal velocity of a cable of density 1.7 must be >considered. If the cable is only an inch or two in diameter >and the lengths are not long enough to whip the ends up to >high speed ("range-safety" equipment is indicated!), terminal >velocity will not be high, and damage will be small. I've never seen any proposal for a beanstalk that thin. >> The thread title says "Beanstalk reprise". > >Beanstalks are a class of tether. Weren't you here for the lecture? > >> Beanstalks aren't possible given today's technology. I >>agree with you... again !! > >Agreed. However, they are possible given MATERIALS known >today. This is a crucial distinction; we know what to shoot >for, and even many of the physical processes required. There was a science fact article in ANALOG Science Fiction/Science Fact a couple of years ago that concluded that, given our understanding of chemical bonds, there was no material theoretically strong enough to build a beanstalk on Earth (on Mars or the Moon, yes; on Earth, no), but that pinwheels would be feasible. Anybody out there who can point us to the appropriate issue of Analog? -------------------------------------------------------------------------------- Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL