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Carefully Timed Jerks Could Power Space Elevator
Hugh Pickens writes "BBC has an interesting article on the long-standing issue of how to power the 'climber' that would ascend a space elevator into space. Previous ideas have included delivering microwave or laser power to the climber beamed from the Earth's surface, but now European Space Agency ground station engineer Age-Raymond Riise has demonstrated a device that could provide a "lift into space" for cheaper space missions along a 100,000-km long tether anchored to the Earth. Riise demonstrated sending power mechanically by providing carefully timed jerks of the cable at its base with a broomstick to represent the cable held in tension, an electric sander to provide a rhythmic vibration to the bottom of the stick, and three brushes representing the climber with their bristles pointing downwards allowing the climber assembly to slide upward along the broomstick as it moved slightly downward, but grip it as it moved slightly upward. 'It would be possible to make a suspension system that completely decouples the cabin where the passengers are,' says Riise. 'For them it would be a linear movement with very little disturbance.' Riise says that he has been approached by commercial elevator companies, who are researching new ideas for elevators in superscrapers where the simplicity of the approach makes it attractive when compared to other ideas for powering lifts, such as compressed air."
This is not flamebait - its a classic seinfeld episode: Synopsis full episode.
For every 'yank' performed on the cable, you pull the anchor lower in orbit.
This is wrong - the transmitting end (ground station) can and would "push" just as readily as it would "pull". Then the vehicle would absorb this wavefront as it converts it to potential energy, such that there is very little energy propagating past it up the cable. You have to consider that this cable is very very long, and at such a scale it becomes more like a slinky, or a piece of string with a cup on each end.
It's worse than that actually. The distance to Geosynch is 36000 km. Moving at a 100 km/h (about 55mph) you'd still be underway for 360 hours. There's no way any climbing-mechanism that depends on mechanical transfer from the ribbon will be able to climb even close to fast enough to make the thing practical.
The demonstration shows a climbrate of around 0.1m/s at which speed it'd reach geosynchornous orbit after about 15 years of climbing. Dumbest idea ever.