<< Sorry man, thats not perpetual motion. You know that magnet that makes it all work? Well when it pulls on the BB it heats up, thus using energy (correct me if I am wrong, although I do know for a fact magnets give off heat while doing work). >>
Yes, indeed. Any self-contained system upon which no outside influence is exerted but which does work (in the case of the BB system, the acceleration of the BB up the inclined plane which stores kinetic and potential energy in the BB during that phase of the cycle) and which does not "wind down", so to speak, is a perpetual motion machine. Since there are always hysteresis losses when work is done on or by a magnet there is generation of heat energy. That heat energy is lost to the system unless it can be reconverted to a form that is useful by the system. There are also frictional forces on the BB during its travels, and those, too, produce heat which is a loss to such a system. No matter how efficient you make such a system, and they can be made amazingly efficient and run for a long time, you can't sustain the behavior forever. If you could, you'd have a perpetual motion machine. And, as you've said, the described system doesn't fit the bill. As a matter of fact that very device, and others similar to it, have long been used as tongue-in-cheek "experiments" for students.
But the specific statement I made that you quoted was referring, of course, to the idea of creating matter and then annihilating that matter. If we could achieve 100% efficiency in such a system we could make it self-sustaining -- once it was set into action by an initial outside influence. But, of course, nothing that we build is 100% efficient in doing work -- well, not by the standards of physics, anyway. We might well be able to propel a device using a matter / anti-matter process, but we'd want to carry the fuel with us, not produce it on the trip. I should have stated clearly that my argument against the idea of producing fuel on the voyage has little to do with the perpetual motion objection. After all no one expects a space ship to be a perpetual motion machine. The whole idea of producing our own source of fuel doesn't work out because it would be silly to go through all the trouble and work of producing the fuel just to derive less power from it than we could have had if we had only used the energy we'd be using for production of fuel to propel the vehicle instead.
Yikes! Haven't had enough coffee. If I had enough caffeine in my system I'd go back over that and clarify it. As it is, I think I'll just post it -- and wander off to the kitchen.
- Collin