In a conversation with a friend recently, she was telling me about a new car that "some Japanese company" had developed, apparently a working prototype that's about to be put into production. It has a rather astounding fuel source: water.
Apparently it operates by using electrolysis to separate the water into hydrogen and oxygen, and then burning the hydrogen as fuel to power the car. Some of the surplus energy runs an alternator, which produces electricity like in a conventional car, some of which is used for electrolysis to produce more hydrogen fuel...
Now, I hear that and my mind goes on yellow alert. That's not technically a description of a perpetual motion machine, but the concept of running both halves of a reversible reaction and turning a profit on the energy involved has "stop in the name of the Second Law!" written all over it.
And yet, according to my friend at least, a working prototype exists and they're about to put it into production.
Is that possible? Is there some missing detail in the description? And is some car company actually producing it?