Science Forums 2

[CraigD]

Originally Posted by alexander

Well, there are machines that do something similar to that already, TEguy, there's a factory in japan that uses mechanisms close to the ones that were used in karakuri ningyo dolls. The factory produces transmissions, and they use carts that use the weight of the transmission to propell the cart forward while compressing a spring that after the cart transports the transmission a few yards to another assembly line, returns the cart back to it's original position, then another transmission goes on it, and the process repeats itself, just like in the karakuri dolls.

Though clearly not perpetual motion – you’ve got to lift weights into it, in the case mentioned, heavy vehicle transmission units, to power it – these sound pretty neat and useful. I imagine they’re something like a railway handcar, though the closes thing I could find via a short web search is this youtube video.

Originally Posted by TEguy

Not to trick people but to really use the machine to do useful work for us without requiring any energy source or fuel that we can see or know of. We should not assume that we have discovered or detected all possible energy sources that could be used for our benefit via a machine of some sort.

As best I can tell, attempts to make machines powered by unknown or unused energy sources are usually termed “free energy” rather than “perpetual motion” machines.

Depending on ones definition of “free energy”, such a machine can be anything from

• conventional photovoltaic cells - sunlight, after all, is effectively unlimited and free

to

• “cold fusion” machines, which purportedly transmute the hydrogen in ordinary water into helium, releasing energy, and which at present appear to or practically impossible or so low-power as to be useless

to

• ”zero-point”, or “vacuum” energy devices, which are in principle possible – Casimir effect measuring experiments routinely measure a force which, were it allowed to move the measuring devices plates, would produce measurable one-time releases of energy – but at present appear to have no means by which they can being “scaled up” into practical power sources – although some interesting, though largely disproved proposals have appeared, such as “sonoluminescent Casimir energy”, an idea championed for a time by Julian Schwinger, and, as I recall, independently by some disreputable Russian Engineer.

Though I understand the consensus is that sonoluminsecence can’t be used to obtain ZPE, the idea is an interesting one. In short, the idea is that, by using sound to generate very small bubbles in a liquid, once can create many small gaps equivalent to the large metal plates used in Casimir effect experiments, and that the collapse of the bubble – which produce the light discharges for which sonoluminsecence is named – perform more mechanical work than is put into the system in the form of sound, which could be extracted as useable work thought, for example, a simple heat engine.

Though no experiment to date appears to have shown that any means of extracting practical, large amounts of ZPE exist, I don’t believe it’s been compellingly shown to be theoretically impossible. The implications were such a device possible, are complicated.