4 ms·

Yes, substantially so. First off, the way stresses work it is substantially easier to build straight up than in any other direction. And secondly, you're miss

Yes, substantially so. First off, the way stresses work it is substantially easier to build straight up than in any other direction. And secondly, you're missing something. Namely, that the only reason why a string attached to an edge of a merry-go-round whips tangentially is because of air resistance. In a vacuum, or if the air was moving with the merry-go-round, the string would be radially-pointing. (There's also a component of "the merry go round is slowing down", but that also isn't particularly relevant.) As such, it makes no sense to build something this way. About the only case where not building straight up would make sense is if you're slightly off of the equator - in which case you should move to the equator. Although I suspect you have the wrong impression of a space elevator. You don't build up, you build down. You have a satellite / asteroid / etc in geosynchronous orbit. You start spooling out two lengths of wire - one down, one up. When the lower one reaches the surface, you anchor it. Then attach a counterweight out beyond geosynchronous orbit.

jfoutz 11y ago
I wonder if it's cheaper to do it with everything moving. a weight with a long cable spinning like Thor's hammer at a given altitude. A payload catches the cable, steals some angular momentum to get kicked up to the next altitude, with the next hammer. If it's close enough to earth, i think the cable will get some induced current, which could spin a gyroscope in the hammerhead, getting some angular momentum back. Actually, i just wonder if this approach has a name, seems like every harebrained idea i've ever had was thought of fifty times before by much smarter people. edit Skyhook! cool.
abduhl 11y ago
Actually, building straight down is substantially easier than straight up. You are incorrect with your statement about "the way stresses work". The reason it is substantially easier to build straight up is due to our implicit basis where up is towards space. This is getting rather high level but stresses are actually tensors and hence are dependent on the chosen basis. If your basis has up pointed towards the north then it is substantially easier to build a different direction than up. This may seem like a semantic argument but it is actually an extremely important distinction when discussing any tensor (position, velocity, stresses).

jfoutz 11y ago

I wonder if it's cheaper to do it with everything moving. a weight with a long cable spinning like Thor's hammer at a given altitude. A payload catches the cable, steals some angular momentum to get kicked up to the next altitude, with the next hammer. If it's close enough to earth, i think the cable will get some induced current, which could spin a gyroscope in the hammerhead, getting some angular momentum back. Actually, i just wonder if this approach has a name, seems like every harebrained idea i've ever had was thought of fifty times before by much smarter people. edit Skyhook! cool.

abduhl 11y ago

Actually, building straight down is substantially easier than straight up. You are incorrect with your statement about "the way stresses work". The reason it is substantially easier to build straight up is due to our implicit basis where up is towards space. This is getting rather high level but stresses are actually tensors and hence are dependent on the chosen basis. If your basis has up pointed towards the north then it is substantially easier to build a different direction than up. This may seem like a semantic argument but it is actually an extremely important distinction when discussing any tensor (position, velocity, stresses).