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Perpetual Motion


Franklin

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well at the risk of sounding Cynical again on yer another Thread, there`s no such thing as a "free lunch" :(

 

however at a stretch, one of thermodynamic laws states that matter/enenrgy cannot be created or destroyed, only changed.

and so in one respect by default, everything`s in perpetual motion. thats how I see it anyway :) not sure if it can be tapped into so to speak though?

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  • 4 weeks later...

A photon may also decay over an amount of time. Since matter has been seen to pop in and out of existance there may be a threshold of energy needed for a photon to retain its form. Entropy over time may require energy to be used just to continue existing. Just my thoughts.

Just aman

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Is perpetual motion possible?

 

I heard that it's impossible to make a machine that would start itself, generate power and continue working for as long as required, without any external energy.

 

I heard that it has something to do with Newton's 3rd law and the fact that we can't generate anymore energy that we have.

 

What is the function of perpetual motion anyway? And why is it impossible (/possible?) ?

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The closest thing to perpetual motion in nature is the current that goes around a superconducting loop. Due to their being no resistance the current can exist for as long as it wants, this implies the loop is kept below its superconducting transition temperature however.

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neo_maya said in post #16 :

Is perpetual motion possible?

 

I heard that it's impossible to make a machine that would start itself, generate power and continue working for as long as required, without any external energy.

 

I heard that it has something to do with Newton's 3rd law and the fact that we can't generate anymore energy that we have.

 

What is the function of perpetual motion anyway? And why is it impossible (/possible?) ?

 

It's the second law of thermodynamics (entropy always increases in a closed system) combined with another thermodynamic law, the law of the conservation of energy.

 

There cannot be perpetual motion machines because:

 

a. The sum total energy of them remains the same.

b. The amount of 'waste energy' (if you will) in the system is certain to increase

 

These two combined mean that the energy used to run the machine will always decrease over time, and thus eventually stop. Hence, no perpetual motion machines.

 

ps.

 

Bonus simpsons quote!

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The water pressure exerted from the tank should force water up into the tube and down again, turning the wheel on its way down.

What really happens, is the tank can't provide enough force to make the water go up into the tube.

And why would it? :D

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greg1917 said in post #17 :

The closest thing to perpetual motion in nature is the current that goes around a superconducting loop. Due to their being no resistance the current can exist for as long as it wants, this implies the loop is kept below its superconducting transition temperature however.

 

A very good and interesting point, could it be possible that for any "motion" to be "perpetual" is must remain in a static form or closed system?

such as a magnet (un-tappable granted) but there non the less :)

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Attempts are made because people are desperate to disprove the laws of thermodynamics and get something for nothing. A mechanical machine like the one in that post is an example of the types of machine thought of over the centuries. Most are due to scientists not yet being aware of the nature of energy and, as mentioned, the laws of thermodynamics.

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There have been a lot of psuedoscience theories put forward about the properties of element 114 and it's abilities to create more energy in a device than it uses. If there is perpetual motion, it can only come from some source like this which is unavailable to us at the moment. We can't do perpetual motion with the things we have now.

Just aman

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