Perpetual motion

[Uncle Martin]

I know this seems a bit silly, but I've got an idea using magnets that seems feasible, at least in my mind. I just haven't had time to try it. Is it truly impossible, or simply not yet done? Does perpetual motion break any laws of physics, or is it only not proven possible mathematically?

Note: I will move this to Inventions and gadgets when Tormod gets a reply to his guitar rig question. I didn't want to bump that down the list.

[Uncle Martin]

Bo, TeleMad, FT, etc... I would appreciate your thoughts on this one please.

[Freethinker]

Work can never be done with 100% efficiency. Work in never equals work out. There is always a loss of energy in the system. Thus it is always neccessary to introduce additional energy into any process in order to maintain it's operation. Thus it is not possible to perfom work without consuming energy. Thus perpetual motion violates the laws of physics.

[Bo]

what freethinker describes is known as the 2nd law of thermodynamics. The idea that this disregards a perpetuum mobile is as follows:
spontaneous processes only occyr if the enthropy increases. Thus causes the system to lose energy E.
Now to put the system back in it's original state the same energy E has to put into the system.
So in principle if we do the energy conversion 2 times (in and out of the system) with perfectly no energy loss a perpetuum mobile can be build.
But The 2nd law also implicates (after some mathematical manipulatyions):
- The energy transfer of one system to another can never be 100% efficient.

Bo

[Uncle Martin]

Originally posted by: Freethinker
Work can never be done with 100% efficiency. Work in never equals work out. There is always a loss of energy in the system. Thus it is always neccessary to introduce additional energy into any process in order to maintain it's operation. Thus it is not possible to perfom work without consuming energy. Thus perpetual motion violates the laws of physics.

A magnet and gravity can both perform a work function without any introduction of, or loss of any energy. Would you consider this an accurate statement?

[TeleMad]

I don't fully understand your intent, but it appears to me that a work cycle would involve going against gravity at some point.

[Freethinker]

Originally posted by: Uncle Martin
A magnet and gravity can both perform a work function without any introduction of, or loss of any energy. Would you consider this an accurate statement?

A magnet consists of a mass in which the magnetic domains of most of the molecules are all oriented in the same direction. It requires energy to make this happen. Magnetic interactions (such as induction in wires moving thru a magnetic field) creates heat (energy loss). Magnetic polarization disapates with time (entropy).

Thus magnatism is like any other potential energy, it takes energy to get it there and it uses energy up (entropy) when it's effects are bing used.

For now I will leave Gravity to someone else.

[Uncle Martin]

I'll have to research this a bit, but I've had magnets holding things for twenty++ years and they are as strong as the day I got them. Maybe I should start a thread on magnetism.

[Freethinker]

20 years is well short of "perpetual". You will also find that if they have been holding things in place, that means they have been exerting pressure/ generating heat, losing energy....

[kerplunk]

I am new here and not really interested in this topic....but i did find this site posted by Janus20 in the test page forum. Maybe it could be of use to you in you theoretical quandry

www.thewebspert.com/cresswell/

I didn't have time to read the whole page (quite large by the way) but it seems to be dealing with the subject that you are discussing. Hope it helps!