Remember the Space Elevator idea?
-
-
@mark said in Remember the Space Elevator idea?:
Space Elevators Are Less Sci-Fi Than You Think
In the explanation:
Me: A combination of gravitational and centrifugal effects, which compete with one another, and vary along the length of the cable. Below geosynchronous orbit, gravity wins, and beyond it, centrifugal effects win. The result is tension throughout, with a maximum amount exactly at geosynchronous orbit.
Colin: It’s Friday night. Use smaller words.
In one of Alastair Reynolds' books, I believe Chasm City, the space elevator plays a major role. It is grounded in Africa, near the equator, iirc to make construction simpler. It becomes the target of a terrorist attack. The "shaft" is severed, letting one portion fall to earth and the other end is propelled into space. The physics of what happens to the "passengers," and the timing of the rescue are an interesting read.
As you may know, Reynolds was an astrophysicist before devoting his time to writing, so he knows a bit about orbital mechanics and the like.
-
“She looked to the man and then to me. "They're saying they've attacked the bridge. They're saying that the explosion's severed the thread.”
In the unreal moments that followed, the elevator continued to climb smoothly.
"Think of the bridge as being like a rope-hanging all the way down from orbit, stretched out by its own weight."
"I'm thinking about it, believe me."
"Good. Now think about cutting the rope midway along its height. The part above the cut is still hanging from the orbital hub, but the part below will immediately begin falling to the ground."
The man answered now. "We're perfectly safe, then? We're certainly above the cut." He looked upwards. "The thread's intact all the way between here and the orbital terminus. That means if we keep climbing, we'll make it, thank God."
"I wouldn't start thanking Him just yet." He looked at me with a pained expression, as if I were spoiling some elaborate parlour game with needless objections.
"What do you mean?"
"I mean it doesn't mean we're safe. If you cut a long rope hanging under its own weight, the part above the cut's going to spring back."
"Yes." He looked at me with threatening eyes, as if I was making my objections out of spite.
"I understand that. But it obviously doesn't apply to us, since nothing's happened."
"Yet," I said. "I never said the relaxation would happen instantly, all along the thread. Even if the thread's been cut below us, it'll take some time for the relaxation wave to climb all the way up to us."
His question was fearful now.”
“Still, it was better to be on the upper part of the thread than the part below the severing point. I imagined a thousand-kilometre-high section below the cut. It would take several minutes for the top of the thread to smash into the planet below-in fact, for a long while it would seem to hang magically, like a rope trick. But it would still be falling, and there was nothing in the world that could stop it. A million tonnes of thread, slicing down into the atmosphere, laden with cars, some of them occupied. It would be a slow and quite terrifying way to die.”
