Even assuming all the conditions needed to make your wormholes a reality, your scenario is not fundamentally different from the magnet-based one above.
If the water can fall out of the exit of a wormhole, where does the energy to make it rise to the entrance of the wormhole come from?
I don’t understand the objection.
“where does the energy to make it rise to the entrance of the wormhole come from?”
The exit is directly above the entrance. When it comes out of the exit, it’s already higher than the entrance.
And I don’t see any problem with that, travelling through the wormhole isn’t fighting against gravity.
In addition to all previous objections raised, any spinning or rotating object is, according to general relativity, going to generate gravity waves which will radiate energy away from the system and eventually stop the spin or rotation.
I like!
You’ve got your entire turbine apparatus in the way. You are saying that you can make the water fall from exit to entrance using the gravitational attraction of the wormhole entrance. But you also say you can get work out of the system via the turbine. Therefore, you will use up more energy keeping your turbine unaffected than you will gain from the falling water. But if you move it to a point where it is not affected, then you have to move your water and that takes also takes energy.
That’s the beauty of thermodynamics. You can make almost your entire setup pure magic, as you have, but any piece that isn’t magic is subject to the laws and negates the magical part.
Whatever is holding up the wormhole against local gravity is contributing the energy.
Think of it like a water mill. The energy to power the mill is provided by the running water.
That’s “free” energy in a sense, but it’s not a perpetual motion machine in the strict sense.
Something outside your local system is providing energy to send the water down the stream. Likewise, in the wormhole case, something is propping up the wormhole so the exit can be at a higher gravitational potential than the entrance.
It’s actually pretty similar to an old idea of sending garbage into a black hole and reaping the energy released. It’s energy we can harvest for free but it’s not really perpetual motion.
Because mass/energy is conserved. You can’t have a machine that is creating energy without having at least as much energy put into it. In the real world, there are things like friction and wasted heat, so you have to put more energy into a machine than you will get out. That’s true everywhere in the universe except maybe at the singularities of black holes, as far as we can tell. You can convert mass into energy (using the equation E = mc[sup]2[/sup]) if you want to and have the right conditions (nuclear explosions and the interiors of stars have good conditions for this), but you can’t create energy from nothing.
The details of your machine don’t matter. Mass/energy is conserved, so there’s no way to get more out than you put in, no matter what kind of machine you use or where you put it.
Isn’t it? The upper end of the wormhole is at a higher gravitational potential than the lower end. That gravitational gradient from entrance to exit will still exist inside the wormhole. It should take just as much energy to push water through the wormhole as it would take to lift that water the same distance outside the wormhole. That energy might have to come from the apparatus maintaining the wormhole, or it might have to be provided by pushing the water ‘uphill’ across the wormhole entrance.
No, I was picturing the apparatus standing on a planet. The water falls from the influence of the planet’s gravity.
Does that affect your answer?
I don’t follow that.
Do wormholes require energy to hold them up?
I thought they are like holes, once created they are just there.
Is that true? Gravity works by warping space. But a wormhole , surely, would cut away from the warp. Wouldn’t it?
Last I heard, a wormhole would once created collapse at the speed of light. The very curvature of space that makes the wormhole exist is also trying to immediately push it closed. Keeping one open will require artificially generating a region of very high negative mass/energy density, which I don’t think we actually know how to do yet, other than possibly on a tiny scale for very short periods of time.
No. A wormhole is just space warped in a really unusual way. It’s still contiguous. If you go through the wormhole and come out at a higher gravitational energy potential than you came in, then somewhere along the way you climbed that gravitational hill. That took energy, which was either provided by the system artificially holding the wormhole open, or which you provided by climbing up the gravity gradient yourself somehow.
Think of it as being like a long windy path up a hill. A wormhole is like finding a door to a staircase inside the hill leading to the top. It’s a shortcut, but you still have to climb up, even if you travel a much shorter distance in the process.
The spinning top in space/vacuum won’t even spin forever. There is the drag of gravity in space-time that will bring it to an eventual halt. Not to mention the eventual proton-death of the device.
And guess what I just lost. :smack:
(but so did you)