Tim Wescott said:
Perpetual motion machine?
Oh, how ideas persist.
The easy answer is that it can't be done, by virtue of conservation of
energy. The hard answer would involve really analyzing all the forces
involved, to discover that before a magnet can push, you have to pull a
bit (or something like that).
Um, So I guess you believe that magnets cannot do work? Guess you never
picked up anything with one? What about solar energy? or nuclear energy?
They are even better than perpetual motion... its free energy.
Do you really think that if we didn't have "perpetual" motion that we would
even be able to do anything? The human body is perpetual motion.
If you talk about getting more energy out than you put in then its easily
done and done all the time(many people, your probably one of them, do it
all the time while "working"). If its a closed system and you take the net
energy then its a different matter.
Nuclear energy, solar, energy, and the human body are "perpetual" for all
practical purposes. Actually perpetual motion is a hypothesis and not a
fact. It is also not conservation of energy. It only supposes that the
entropy is 0 and not negative. The 2nd law does state that entropy increases
over time but technically it could be constant too(quasi increasing). The
subtle point I'm trying to make is that for pratical purposes it depends
only on maximizing efficiency.
In any case, you are forgetting, I guess in your old age!?!, that magnets
have the ability to do work. Something created the magnets and did work on
it and those magnets can use that energy to do work(same principle as
nuclear energy or chemical energy or whatever else). This is why natural
magnets loose there magnetism over time.
So for the original post, it is possible but chances are the friction is to
much for the magnets. One could get practical perpetual motion by using
solar energy to overcome the fricition. It might not technically be
perpetual motion according to physics but no one would be around to see it
stop.
Hell, we don't even know if gravity is conservative but we treat it as so
for all practical purposes. I guess your problem is that you have to
distinguish free energy devices from practical perpetual motion. The guy
isn't claiming is device will run for ever and probably doesn't care. I'm
sure he would be happy if it ran for a few hours.
