Comment I'm Skeptical (Score 1) 618
After reading the FAQ by this company, I still can't see how this is going to work. Let's do some physics, shall we. Maybe someone will enlighten me.
The elevator *and all of it's parts* are to be in geostationary orbit. So, figure out what speed is required to keep something in orbit around the Earth at distance r from its center.
m_E : mass of earth
m_e : mass of elevator element
G : Newton's const.
r : distance from center of Earth to elevator element
v : speed of elevator element
Because gravity and centripal force have to cancel,
G m_E m_e / r^2 = m_e v^2 /r
or
G m_e / r = v^2
So, if you are at distance r from the center of the Earth, you need
v = ( G m_e / r )^(1/2)
of speed to stay up. Note that as r gets bigger, v gets smaller. Now, to be in geostationary orbit, one needs to relate v and r like so:
v = 2 pi r / (1 day)
and one gets the answers for r and v. (something like r= few 10^5 kms and v = ~7km/s.)
Because this elevator *from top to bottom* has to be in geostationary orbit to even exist, the bottom part will be moving too slow and the top (if it goes past the geostationary point) will be moving too fast and will want to fly off. To keep everything in check and together, some bad ass rope has to be used.
Let us assume one can get something that is 1) strong enough so it all stays together and 2) light enough so the graviational pull of the lower part of the rope doesn't bring everything down. (Remember gravity gets stronger as you approach the earth.) We now have a perfect system in theory and if all there was in the Universe was the Earth and the elevator, it just might work, and once you have it built, don't touch it because if anything changes in v or r, the whole thing will come down if it doesn't snap off first.
What I mean is, the whole elevator is going to be undergoing perturbations from a number of graviational sources like the sun and moon. The platform will have to have some thrusters on it to *constantly* correct for these perturbations and also for the load that is being hauled up the rope. Can you guess how much energy you might need to compensate the load on the rope when something is going up? Think about energy conservation. It'll be alot like the energy needed to put the load into orbit via run-of-the-mill rocketship.
So, to me it just doesn't look feasible (ie worth it). Feel free to tell me otherwise.
PS. This would be an awesome thing to put into some mechanical simulation software.
The elevator *and all of it's parts* are to be in geostationary orbit. So, figure out what speed is required to keep something in orbit around the Earth at distance r from its center.
m_E : mass of earth
m_e : mass of elevator element
G : Newton's const.
r : distance from center of Earth to elevator element
v : speed of elevator element
Because gravity and centripal force have to cancel,
G m_E m_e / r^2 = m_e v^2
or
G m_e / r = v^2
So, if you are at distance r from the center of the Earth, you need
v = ( G m_e / r )^(1/2)
of speed to stay up. Note that as r gets bigger, v gets smaller. Now, to be in geostationary orbit, one needs to relate v and r like so:
v = 2 pi r / (1 day)
and one gets the answers for r and v. (something like r= few 10^5 kms and v = ~7km/s.)
Because this elevator *from top to bottom* has to be in geostationary orbit to even exist, the bottom part will be moving too slow and the top (if it goes past the geostationary point) will be moving too fast and will want to fly off. To keep everything in check and together, some bad ass rope has to be used.
Let us assume one can get something that is 1) strong enough so it all stays together and 2) light enough so the graviational pull of the lower part of the rope doesn't bring everything down. (Remember gravity gets stronger as you approach the earth.) We now have a perfect system in theory and if all there was in the Universe was the Earth and the elevator, it just might work, and once you have it built, don't touch it because if anything changes in v or r, the whole thing will come down if it doesn't snap off first.
What I mean is, the whole elevator is going to be undergoing perturbations from a number of graviational sources like the sun and moon. The platform will have to have some thrusters on it to *constantly* correct for these perturbations and also for the load that is being hauled up the rope. Can you guess how much energy you might need to compensate the load on the rope when something is going up? Think about energy conservation. It'll be alot like the energy needed to put the load into orbit via run-of-the-mill rocketship.
So, to me it just doesn't look feasible (ie worth it). Feel free to tell me otherwise.
PS. This would be an awesome thing to put into some mechanical simulation software.
