Can we mimic a perpetual motion machien?

[Ziknich]

Good day to all!

I read a small article in MIT's engineering.edu page. The article talks about perpetual motion machines, it says that we cannot create one, but we can mimic it.
My question is: how can we mimic this perpetual motion machine? Has it been mimicked before? And if yes, how?
I hope you can help me answering these questions.
Thank you!

Oh! The article I read was this:
http://engineering.mit.edu/ask/it-possible-construct-perpetual-motion-machine

 

[Ibix]

All he means is that we can build things that take a long time to stop whatever motion they are supposed to do. A pendulum that will stop swinging in seconds if left to its own devices can run for a week off the energy stored in a spring or a lifted weight.

 

[jedishrfu]

Or a Foucault pendulum may appear to some as a perpetual motion device until you understand how it works:

https://en.wikipedia.org/wiki/Foucault_pendulum

Please note that some of these pendulums may have motors to keep them in motion to counter air resistance:

Air resistance damps the oscillation, so some Foucault pendulums in museums incorporate an electromagnetic or other drive to keep the bob swinging; others are restarted regularly, sometimes with a launching ceremony as an added attraction.

 

[Ziknich]

Has it been mimicked with electromagnetism or some mechanism that uses magnets?

 

[jedishrfu]

I imagine you could hook up the motor to a solar panel and keep it recharged enough to run for a very long time which would be an approximation to perpetual motion.

If the system does some kind of work (moves against a frictional force as an example) then it will lose energy unless its replenished externally and that's why perpetual motion machines can't exist in nature (see link and quote below).

https://en.wikipedia.org/wiki/Perpetual_motion

There is a scientific consensus that perpetual motion in an isolated system violates either the first law of thermodynamics, the second law of thermodynamics, or both. The first law of thermodynamics is a version of the law of conservation of energy. The second law can be phrased in several different ways, the most intuitive of which is that heat flows spontaneously from hotter to colder places; relevant here is that the law observes that in every macroscopic process, there is friction or something close to it; another statement is that no heat engine (an engine which produces work while moving heat from a high temperature to a low temperature) can be more efficient than a Carnot heat engine.

 

[DrClaude]

My question is: how can we mimic this perpetual motion machine? Has it been mimicked before? And if yes, how?

The answer in given in the article:

Only by engineering a solution by which an object in motion can consume some store of energy or gather energy from an external source can we approximate perpetual motion.

 

[Ziknich]

Thank you for all the fast replies!

 

[jedishrfu]

Thanks for all the responses so far, I think we have answered the OP's original question and now we can close this thread before perpetual motion can take over the discussion.

-- Jedi

 

[Ibix]

Thanks for all the responses so far, I think we have answered the OP's original question and now we can close this thread before perpetual motion can take over the discussion.

You forgot to lock it, so I'm just going to repeat the OP word for word and see what happens...

 

[jedishrfu]

Closed now so as not to perpetuate the perpetual motion notion for another cycle of posts...