Heat is bad. It represents energy the system has lost, and can not be recovered.DrillbabyDrill said:
Consider gold. It is possible (though not practical) to create gold using nuclear reactions, but apart from that, the amount of gold that exists on earth has always been here. It can't be created, and it can't be destroyed. It can be melted, vaporized, mixed with other metals, pounded into thin flexible sheets that are almost weightless, or made into heavy bars. But there is always the same amount of gold, though some of it is underground where we haven't found it yet. Energy is the same way. It can be created (and very practically, too!) using nuclear reactions, but apart from that, and the energy poured onto our planet by the sun -- which of course is a giant nuclear reaction -- and radiated back into space, the amount of energy we have is always the same, though some of it is underground where we haven't found it yet. Energy can be heat, or electricity, or mechanical, or chemical, among other things, but it can never come from nowhere. A gasoline engine turns chemical energy into mechanical energy, with a lot of it escaping as heat. An electric motor turns electric energy into mechanical energy, with a little of it escaping as heat. A generator turns mechanical energy into electric energy, with a little of it escaping as heat. If you try to combine an electric motor and a generator you always end up with less energy than you started with, because some of it always gets away as heat. And that is without any mechanical energy left over to make the car move!DrillbabyDrill said:
Very nicely done, David, but I was trying to focus on an aspect that you seemed to dismiss quickly as obvious. I think the real problem is that most people are totally unaware that there is a first law of thermodynamics, and its very existence makes no sense to them at all. I mean, come on! I pour a gallon of gas into a car and it goes, and goes, and goes. Something has to be creating energy to make that work. I stop, and there is obviously no more energy. Somehow that energy just disappeared. Without even realizing it, most people think of energy as transitory. So why shouldn't we be able to create some with a generator connected to the rear wheels?adric22 said:
Oh.. and in the video I never actually got back to my point about the auto mechanics. It seems to me that people who work on cars are the most likely person to argue about the perpetual motion issue. And I think the reason is because many of them have held an alternator in their hands and seen how easy it is to spin. But obviously it would be impossible for them to have experienced the drag since it would need to be in the car and belted up before it would produce any. The general public seems a bit more willing to accept my argument when I explain to them about the drag of the alternator.planet4ever said:
