Perpetual motion machine

[moonlord]

I've got it now. Well, I don't think the analogy is quite correct, but I see the point. You think that if energy/mass is not conservated anymore, the universe will cease to exist.

[batmanmg]

yes, but not right away, and in fact, unless you can find a way to avoid being destroyed by the big crunch/next big bang, like escaping through 4d space into another universe, then any device you creat will be destroyed, and therefor the balance restored, and the perpetual motion device wouldn't be very perpetual at all.

[Super Hans]

It all depends on whether you want yuo perpetual motion machine to just run forever, or if you want to be able to extract work from it and it still run forever. The first is possible in theory, and impossible in practice, and the second always impossible (conservation of energy).

Can't use a giant rotating space magnet (would be cool though) as the induced current would induce it's own magnetic field to oppose the magnet's field slowing the magnet. In the end the net gain of electrical energy will be less than or equal to the initial energy the spinning magnet had.

The Casimir effect is really as close as you can get as it is pretty much extracting energy from the universe itself.

Casimir Effect

[holomanga]

My idea would be a ball falling around the surface of a tesseract. it would keep on going forever, and we would be able to attach turbines to it.

[Keiji]

...And what would make it keep on going forever?

[holomanga]

If the ball was magnetic, and the tesseract was spinning in a vaccuum above a magnet, and for some reason or another gravity was not present, then the tesseract would rotate forever, with the ball falling down round it's surface.

[Keiji]

Yes, the magnetic ball would move forever. However, as soon as you tried to harvest its kinetic energy by "attaching a turbine to it", you'd slow the ball down and eventually it'd stop.

Planets orbit around their stars forever, but that doesn't mean planets are perpetual motion machines.

[holomanga]

In theory, you could make a machine go forever by taking smaller and smaller amounts of energy from it. So take 1 energyunit from it, then 0.5, then 0.25, and so on. It will keep on running forever.

[PWrong]

Then you'd only get a finite amount of energy from it.

[anderscolingustafson]

Light would have perpetual motion as it never stops and anything in space just floating between galaxies would have perpetual motion as there would be nothing to stop it from moving. Also the galactic clusters have perpetual motion as they are speeding up in their movement away from each other instead of slowing down. Perpetual motion may be rare but it does exist in nature.

[holomanga]

It seems the universe expanding plucks energy out of nowhere, so if we could slow down the expansion of the universe we could get infinite energy.

[PWrong]

Are you guys just guessing what perpetual motion means? You have a magic box in front of you that can tell you the meaning of any word, you don't need to guess.

[mghtymoop]

Perpetual Motion, or very close to it, is easy, take an object into the vacuum of space, point it away from any other objects strong gravitational forces and give it a shove, done...

[holomanga]

I don't have a magic box in front of me that can tell me the meaning of any word though.

[Keiji]

This is getting quite ridiculous.

Yes, of course anything in space that is not being slowed by atmospheric drag would continue moving forever, due to Newton's First Law:

First Law: Every body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force. This means that in the absence of a non-zero net force, the center of mass of a body either remains at rest, or moves at a constant speed in a straight line.

That does not mean it is a perpetual motion machine. A perpetual motion machine is something which produces more energy than it consumes - by continuing to operate at the same velocity while energy is being taken from it.

Objects moving through space do continue to move at the same velocity, but no energy is being taken from them.

[PWrong]

I don't have a magic box in front of me that can tell me the meaning of any word though.

Describe the object you're looking at right now, the one that is currently inches away from your face.

[Chronicus]

I don't know if a perpetual motion machine is possible but I don't think one can write it off with Thermodynamics, either.

I don't pretend to know what I'm talking about in this regard, but I found these videos to be rather interesting:

http://www.youtube.com/dancombine

[student91]

This is getting quite ridiculous.

Yes, of course anything in space that is not being slowed by atmospheric drag would continue moving forever, due to Newton's First Law:
[...]
Objects moving through space do continue to move at the same velocity, but no energy is being taken from them.

Couldn't you argue, due to relativity, that the thing isn't moving at all?

[wendy]

Something that is rotating, or travelling in an orbit, does experience some form of 'proper motion'. Relativity, either that of Newton or Einstein, has no bit to play here.

[Klitzing]

Well, energy is just the integrated force along some path.
Traveling without force thus implies no energy gain possible.
--- rk

[ICN5D]

An idea I've always had was a perpetual motion machine using wormholes. Assuming these wormholes don't require gravity to exist, they could be used to power an infinite energy generator. Let's say one was placed above the other, in a gravity field, and we place the bottom wormhole in a container of water. There would be a continuous flow of water going in the bottom and coming out of the top, only to be caught by the bucket again. Then, enclose this flowing system to prevent evaporation, and place a hydroelectric turbine in the middle. Voila, there's your power generator, assuming that the wormholes don't require the power of a 1000 tesla magnet, in order to bend space

[Keiji]

Except that assuming wormholes exist, gravity fields extend through them (very much unlike the popular video game Portal!). So it would take the same amount of energy for the water or anything else to be raised from the bottom wormhole to the top one, regardless of whether it went through the wormhole or not.

[ICN5D]

Okay, I'll buy that. Portal is a great game, by the way. It's probably capable of rendering a virtual reality 11-cell, or any Source engine for that matter.

How about another continuous flowing system? This one would require a temperature of incredibly cold, somewhere around a few degrees of absolute zero, and gravity to work. In the darkest reaches of interstellar space, it gets to a best of 3 to 4 Kelvins. I remember learning about superfluid helium and how it is attracted to magnetic fields. In the magnetic fountain experiment, the superfluid is flowing up and out of the container, towards a magnetic field, against the pull of gravity. If using a permanent magnet, and maintaining the temperature properly, it should allow for a continuous flow. How to harness this kinetic energy? Good question! Superfluid helium has the special property of zero viscosity, so this would create a problem when trying to move something else with the moving mass. One cannot really stir up a bucket of superfluid helium, with a spatula. In addition to the fluid always trying to slide up and out of any container, the containment issue is also present. But, it's worth a few thought experiments. Perhaps the second-sound property from heat dissipation can be harnessed, or even the third-sound, where a layer only a few microns thick will develop wave propagation to dissipate heat. The quantum world still has yet to show itself completely, if it ever will. There may still be some strange things that can be done!