* This kind of machine is impossible as it would violate the law of thermodynamics.

Machines of the First Kind:
* Machines of the first kind produce work without any energy being input to the machine.

* This is a clear violation of the first law of thermodynamics, which says energy can neither be created, nor destroyed – only converted.

Machines of the Second Kind:
* The second kind converts thermal energy into work, without any other inputs, at complete efficiency.

* While this doesn’t violate the first law (no energy is being created, just converted), these machines fall victim to the second law of thermodynamics.

Machines of the Third Kind:
* Machines of the third kind completely eliminate friction, and therefore continue a motion forever due to inertia.

* While many have tried, friction cannot be completely and utterly eliminated in any system.