Why is it so difficult to build a perpetual motion machine?
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Because if friction. It’s impossible at this point to completely eliminate friction in a pep motion machine so over tome, no matter how efficient it is, it will eventually stop. At that point it can’t be a pep motion machine anymore.
my understanding is, everything uses energy, so if the machine makes a noise, that’s lost energy, heat, light, friction etc all the same. since its impossible to eliminate all of those factors its impossible to have perpetual motion – even if by some mirical someone worked it out, it would be useless as you wouldn’t be to generate with it as some energy would be lost in generation, therefor no longer being perpetual.
sounds right in my head but I’m no scientist 😂
The ask of a PMM is to give you something for nothing. The third law of physics is that for every action there is an equal and opposite reaction; EQUAL
If you push a ball with x force, it will only accele by x force. If it goes faster, then some other force has to be acting on it. M
There will always be friction or air resistance or gravity or some forced which prevents more energy output than input.
You can’t have an infinite waterfall or an infinite newtons cradle because of friction, drag, and a host of other factors.
So, you’ll never get more out of something than you put into it. The best we can do is an output equal to the input
To a certain degree and under a very loose definition, gravity kind of is a perpetual motion machine. Technically the mass of the Earth is perpetually accelerating objects toward the center of its mass.
It isn’t difficult, it’s impossible. It might be useful to define a term quickly: a perpetual motion machine is a device that never needs more input energy to sustain it once it stars moving. The fascination historically has been that this could be a limitless source of free energy. However, it runs up against a set of physical laws called the laws of ‘thermodynamics’. Thermodynamics is just a complicated wad of saying ‘the movement of energy’. These rules define how efficient any system can be. Under those rules no system can (even theoretically) be 100% efficient. As such, any ‘machine’ whether mechanical, chemical or whatever must always ‘lose’ energy to that inefficiency in the form of heat, light, sound, ‘disorder’ or several other routes. Over times these loses will take all of the energy away until the energy left to cause motion is all gone
“so difficult” should be “impossible”
Thermodynamics have laws. To the best of the worlds understanding of physics, these are absolutes. If there is deviation it would change the fundamental understanding of the universe.
Law 1-Energy cannot be created or destroyed. Aka, no such thing as a free lunch.
Power for movement needs to come from somewhere. Something falling, is still just converting potential energy into kinetic. Cars move from energy inputs from gas or electricity which is converted into kinetic.
Law 2- A system will move towards disorder. In effect, every time energy is converted, some of it is wasted.
Outside of a 101 level physics class homework problem, everything has friction.
Air contact? Friction.
Greased metal on metal? Friction.
Converting gasoline potential energy into kinetic? Friction *and* waste heat.
There is no system where you can put 1 potential energy in, and get 1 or more kinetic energy out.
Making a perpetual motion machine is basically impossible because in reality there are always efficiency losses. Moving components experience friction, generate heat, light, sound etc, it’s just the nature of materials and physics and we don’t have any way to avoid it.
Making a perpetual motion machine that can also produce useful energy is literally impossible because the laws of physics say you can’t extract more energy than you put in to the system. So even if you could somehow make a PMM that didn’t experience any losses, you wouldn’t be able to do anything with that motion, and you’re certainly not getting free energy out of it, the energy has to come from somewhere.
Well technically speaking there are already objects in perpetual motion, the moon and earth are both examples. There’s nothing in space so there’s nothing to slow it down so it moves perpetually.
What I think people mean is that they want something to be able to extract a surplus of energy from and have it still remain in motion the entire time. The moon is slowly moving away from earth, something is giving it additional energy to be able to grow its orbit. Energy that can be extracted from tides on Earth. This could be a theoretical perpetual motion machine but it will still stop eventually when the sun burns out.
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