I know the *base* of the story, every single system doing any kind of work leads to a certain loss of energy, basically what makes perpetual motion machines impossible, as without pumping more energy into the system, the one it already have will eventually all be exchanged in the form of friction and whatnot.
But I want to go to the *fundamentals*, why is it like that? Why is it impossible? Why can’t we imagine a hypothetical machine made with whatever unobtainium we might need that is actually, mathematically energetically perfectly efficient? *Why did heat beat us? xd*
In: 3
From the moment two objects are interacting in some way with each other, they’re exchanging energy. It’s not just about simply friction
The problem with perpetual motion machines though is not that they’re impossible but that they’re useless. Aside from making cool desk toys, a theoretical perpetual motion machine would be in perfect equilibrium, containing exactly as much energy as it needs to perform its action and losing none of it in the process. If you tried to harness that energy, then you’d be inevitably be taking energy from that system, disturbing the equilibrium and making the machine eventually stop. So we don’t just need a machine that loses no energy but a machine, or process, that produces more energy than it consumes, which is physically impossible.
There’s a lot more at play than just friction, no interaction of any sort is lossless. It goes from a higher energy state to a lower energy state, otherwise it’s not moving or doing anything at all. Remove air friction and there’s material friction, remove material friction by for example using magnets but even magnetic interactions are not lossless. Remove magnets somehow even just gravity is not a lossless exchange of energy. Of course we usually think of gravity on a huge cosmic scale in which there’s essentially limitless reserves of energy but even they are not in fact limitless. Sure Launching a rocket from earth does not make a noticeable difference but in actuality it does, it ever so slightly takes away from the earth’s momentum.
Latest Answers