Why are “perpetual motion” machines impossible, when Newtons Laws of Motion seem to suggest they are possible?
There is nothing in Newton’s Laws of Motion which explicitly prohibit the existence of a “perpetual motion machine”. As a result in the years after after Newton established the laws of motion, scientists conducted a lot of research into developing one. However instead of developing such a machine, this research resulted in the discovery of the Laws of Thermodynamics which govern (among other things) how energy translates into “work”. The Second Law of Thermodynamics is the law which specifically prohibits perpetual motion machines. Essentially this law says that no matter how efficient a machine is, some energy will be lost to heat, and ultimately all of the available energy to run the machine will be lost. In recent years scientists have experimented with “low friction” machines which seek to minimise the amount of heat lost. Some remarkable devices have been built, including some flywheel devices which operate for years at a time. Regardless all of these devices are still subject to
