3 ms·
If you were in a vacuum, that could be a wonderfully efficient way of converting mechanical movement into kinetic energy. We have to deal with atmospheric frict
by MPSimmons 12y ago
If you were in a vacuum, that could be a wonderfully efficient way of converting mechanical movement into kinetic energy. We have to deal with atmospheric friction, though, and the places where the cannon would launch from (the surface) has the thickest part of the atmosphere, so the most friction.
- nraynaud 12y agowhat about vacuuming the cannon? like those ping pong ball cannons?
- SideburnsOfDoom 12y agoWhat happens when you leave the cannon? Either the cannon exit is near ground level, in which case you still have the air resistance problems; or it's not, in which case you have the problems of building very a tall cannon.
- nraynaud 12y agoyou don't have to exit the cannon at high speed, the v^2 drag will kill you. You're just trying to put some kinetic energy in the rocket in a way that doesn't make you carry it. you don't have to put all the energy in it that way, the current system works, it's just a tentative improvement. But your answer makes me feel you've not seen the ping pong ball cannons, because they have very good results with a very low mass.
- Symmetry 12y agoYou would also have to vacuum all the space between the cannon and space, and at that point you have a space elevator you can just climb up.
- Symmetry 12y agoThat's why some people have thought about sending a fuel factory to the Moon, refining the fuel there, and using mass drivers to send it to Earth orbit for serious interplanetary missions.