I would like to know if free energy devices are possible to build,Which will run forever. Well tesla was first believed to have built such a device,And later on many scientists have also claimed to have built similar devices. So what could be the source of energy behind it
“So what could be the source of energy behind it” is actually the answer to your question. If a “source of energy” is required to keep it (whatever it is) going, then it is not perpetual…without that source, it would eventually stop.
A perpetual motion machine is possible if and only if that machine is frictionless. If it were frictionless and a force were applied momentarily to accelerate it, it would run forever even after the force is removed. Once a mass is moving, the laws of momentum say that mass will continue moving until another force is applied to stop it.
Unfortunately, there is no such thing as a frictionless machine. Science has done remarkable things to reduce, but not eliminate, friction. So kinetic energy (the motion) is continually dissipated as heat. In the end, without adding energy, the machine runs out of kinetic energy and stops.
on: 3rd January 07