Re: [MLUG - DISCUSSION] Perpetual Motion Machine?

[Mike Miller <EMAIL:PROTECTED>]

On Fri, 1 Sep 2006, Stephen Montgomery-Smith wrote:

> > I don't understand.  How can we use gravity to fling probes into space? 
> > I don't think you can extract energy from the gravitational field of a 
> > planet (or moon or sun), but you can use it to reroute a craft or 
> > probe. Maybe this is what you are thinking of:
> >
> > http://en.wikipedia.org/wiki/Free_return_trajectory
> >
> > Can that be used to speed up a probe or just to redirect it?
>
> I have heard of the sling shot effect, where a probe going around a 
> rotating planet is given more velocity.  The planet loses a small 
> (non-measurable) amount of rotational energy.


After reading your last answer, I was thinking that the Earth is moving at 
18 miles/sec around the Sun so it could essentially sweep things along for 
a bit and fling them away.  Theoretically, it would slow the Earth down a 
little.  This is what you are saying, I think.  It makes sense.

Of course, this isn't something we can use to produce energy on Earth, if 
I'm understanding it.

Mike

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