[Volontari] OT - Energia Libera: motore magnetico

[Mihai T. Lazarescu]

On Sun, May 25, 2008 at 04:43:21PM +0100, giovanni a dimingo.com wrote:

> Pare che esistano dei motori magnetici che sono in grado di
> produrre energia senza mai fermarsi (forse i magneti si
> scaricano dopo circa 400 anni).
> 
> Qualcuno avrebbe gia' costruito un'auto con motore
> magnetico:
> http://www.youtube.com/watch?v=BM0-fjvFNfU
> 
> Altri video al riguardo:
> http://youtube.com/watch?v=PFGiWiXMHn0&feature=related
> http://youtube.com/watch?v=6LAUAsIosjc&feature=related

http://en.wikipedia.org/wiki/Perpetual_motion

    Scientists and engineers accept the possibility that
    the current understanding of the laws of physics may be
    incomplete or incorrect; a perpetual motion device may not
    be impossible, but overwhelming evidence would be required
    to justify rewriting the laws of physics.

    The conservation laws are particularly robust.  Noether's
    theorem states that any conservation law can be derived
    from a corresponding continuous symmetry, and the theorem
    can be proven.  In other words, as long as the laws of
    physics (not simply the current understanding of them, but
    the actual laws, which may still be undiscovered) and the
    various physical constants remain invariant over time --
    as long as the laws of the universe are fixed -- then the
    conservation laws must be true, in the sense that they
    follow from the presupposition using mathematical logic.
    To put it the other way around: if perpetual motion or
    "overunity" machines were possible, then most of what we
    believe to be true about physics, mathematics, or both
    would have to be false.

In questi particolari casi è da vedere se i magneti non vengono
usati come delle batterie che si svuotano nel tempo.  Produrre i
magneti costerebbe più energia di quando forniscono nel motore.

Ciao,

Mihai