Perpetual motion machine device thing.

[FriedChicken]

I have an idea on how to make a perpetual motion device/machine. Imagine a hollow doughnut made of see-through plexiglass under a vacuum . Inside is a magnetic floating car thing, and along the side and bottom are magnets holding it up. You could get it turning by kind of turning the contraption until the car starts moving, and then just set it down. It'll just keep moving and moving and moving, never ending. The only thing that could stop it is photons emitted by whatever light source affects it. In fact you could use these photons by putting a piece of metal at the top with one side white and the other black. The light would be reflected on one side, and absorbed on the other.

 

 

Could this work?

[the tree]

No, perpetual motion machines do not ever work, ever.

[Klaynos]

You're spinning magnets inside a magnetic field and hopeing it'll stay in the same place?

 

Where do you get the magnets from, what generates the magnetic field. Resistance from the magnets on the field? Not perpetual motion.

[Sisyphus]

Perpetual motion machines can work, theoretically, you just can't get more energy out than you put in. But if something isn't using any energy to keep moving (and motion itself doesn't inherently require energy, just acceleration), then sure, it can be perpetual. However, in practice, that's never actually going to happen, since there's no such thing as a completely isolated system.

[FriedChicken]

Perpetual motion machines can work, theoretically, you just can't get more energy out than you put in. But if something isn't using any energy to keep moving (and motion itself doesn't inherently require energy, just acceleration), then sure, it can be perpetual. However, in practice, that's never actually going to happen, since there's no such thing as a completely isolated system.

 

Why wouldn't the above be seperated from everything?

If you perfectly align the magnets, then you could just send it spinning around in circles, the repelling magnets holding the car up. You wouldn't be getting more energy then you get out, that's obvious. You just need to get it started, and then you're finished.

[Severian]

Why wouldn't the above be seperated from everything?

If you perfectly align the magnets, then you could just send it spinning around in circles, the repelling magnets holding the car up. You wouldn't be getting more energy then you get out, that's obvious. You just need to get it started, and then you're finished.

 

I can think of plenty of dissipative effects. For example, the disc would have to be metal to be held up by the magnets. So it conducts electricity and the magnetic fields would create eddys of electric current in the disc which dissipate energy.

[FriedChicken]

I can think of plenty of dissipative effects. For example, the disc would have to be metal to be held up by the magnets. So it conducts electricity and the magnetic fields would create eddys of electric current in the disc which dissipate energy.

 

The disc doesn't need to be metal. You could just attach magnets to it. It will be opposite poles repelling eachother as the little car runs around in a vacuum.

[insane_alien]

but the magnets would be metal. so the effect would still be present.

[Sisyphus]

Well, for one thing, the magnets are metal. Also, if it's "see through," then you've got photons coming in, being, absorbed, reflected, reradiated. For that matter, if you can detect that it's moving at all, it's not isolated. And exposed to a vacuum, plexiglass is going to ever-so-slightly decay and release particles into that vacuum. Plus there's gravitational influences, especially since you're moving stuff around.

[swansont]

Plus, even a really good vacuum still has a fair number of atoms floating around in it, and it's only a really good vacuum if you continually pump on it.

[Severian]

Not to mention vacuum fluctuations themselves...

[YT2095]

you also have to account for Vapor Pressure on the plexiglass, a vacuum THAT perfect would atomise it

[DaveC426913]

I have an idea on how to make a perpetual motion device/machine. Imagine a hollow doughnut made of see-through plexiglass under a vacuum . Inside is a magnetic floating car thing, and along the side and bottom are magnets holding it up. You could get it turning by kind of turning the contraption until the car starts moving, and then just set it down. It'll just keep moving and moving and moving, never ending. The only thing that could stop it is photons emitted by whatever light source affects it. In fact you could use these photons by putting a piece of metal at the top with one side white and the other black. The light would be reflected on one side, and absorbed on the other.

 

 

Could this work?

 

This is not a perpetual motion machine, this is simply a demonstration of Newton's First Law:

 

"Objects in motion tend to stay in motion ... unless an outside force acts upon them."

 

All objects in the universe obey this law.

[YT2095]

another thought, since this is a Doughnut shape, then the application of the law above dictates that there will invariably need to be Frictional forces to keep the "car" going around in a circle, a Linear path would preclude this.

[Klaynos]

Indeed it has to be accelerating as it's turning.

[swansont]

But circular motion does not inherently involve a change in energy, since the force is perpendicular to the velocity.

[Sisyphus]

But circular motion does not inherently involve a change in energy, since the force is perpendicular to the velocity.

 

Indeed. Any gravitational orbit is a demonstration of this.

[FriedChicken]

Ok, so it's not a perpetual motion machine.... But I still want to build one of these things. Imagine a little doughnut with a little something constantly going around in circles for hours, maybe even days on end.