Bessler. Da Vinci. Bhaskara. All these famous historical figures have at some point attempted to create a perpetual motion machine, on paper or in real life. Perpetual motion is a concept that has been chased throughout the ages, despite the failure of EVERY contrived machine. Though an application of Isaac Newton’s second law of motion—acceleration is dependent on the mass of an object and the force acting on that object—persuades many that perpetual motion is indeed possible, the fact remains that it is not. Perpetual motion comes into conflict with the first law of thermodynamics and Newton’s first law of motion; therefore it is not possible.
Violation number one: the first law of thermodynamics states that energy cannot be created or destroyed. Why wouldn’t a perpetual motion machine work, then? Because perpetual motion machines are required to provide their own energy. Seemingly oblivious to this fact, creators of these devices have contrived one of the basic types of perpetual motion machines: Part A powers Part B powers part A. While this would work in the inventor’s imagination, Part B of the contraption would have to create enough energy to properly fuel Part A without running out, clearly violating one of the basic laws of physics. But there is yet another law that this concept clashes with.
Newton’s first law of motion is critical to understanding the flaws of perpetual motion machines. It states that an object at rest stays at rest and that an object in motion stays in motion unless acted on by an unbalanced force. The unbalanced force that causes the malfunction of the device most often is friction, a force that has a talent for bringing machines to a grinding halt. Friction is caused when two objects, whether solid, liquid, gas, or other, rub up against each other. Naturally, any “perpetual motion” contraption would not be allowed to have any moving parts. BUT ALL OF THEM DO.
If perpetual motion still doesn’t seem fishy, consider this: In order to have a perpetual motion machine work, even if it didn’t have moving parts that touched, it would have to be operated in a vacuum so there would be no friction between the machine and the air or water. Building a machine with no moving parts that touch is a big enough challenge, but for this crazy dream to be accomplished, you must find a vacuum suitable enough for this device. No vacuum on Earth will suffice, so space seems the next best option, right? Wrong. There is a material in space called the interstellar medium that creates friction between it and everything that moves. Sorry. No perpetual motion machines allowed.
A true perpetual motion machine can be considered the ultimate prize in physics, but one that will most likely never be won. Such a machine that provides its own energy without external sources will exist in only one place for a very long time: humanity’s minds.
Perpetual Failure: Why Perpetual Motion is Impossible
By Anna D.
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