Re: impulse/momentum

[Brian Whatcott <betwys1@SBCGLOBAL.NET>]

Newton kindles the juvenile imagination when he relates the tenacious
symphony of the spheres.
But when  this same mass in consideration is quasi-infinite in the context,
that looks more like an article of faith provided by an educator:
the tender wheels of the student's traction falter at the concept,
 do they not?
Better to ask the young to imagine what they can imagine.

A water jet impinging upon a fixed pelton wheel does not in
fact cause some contra-rotation of the Earth mass - no indeed.
 The force is reacted much, MUCH closer to home.
So teachers who talk of the Earth moving, are in the position of
 discussing Angels Dancing Upon Pin Heads - and I disapprove
the dishonesty of it.

Brian W

At 03:04 AM 12/13/2003,  Mark Sylvester, you wrote:
>  [ Brian Whatcott ]
> >I expect I am missing something here.
> >If I want to test a pelton cup by fixing it in a lab sink,
> >I can see the water flow reversing, and I can see that the
> >cup remains stationary, so if one wants to satisfy an equation
> >by considering that the Earth mass rotates in reaction, I suppose
> >that's OK. But isn't it a bit forced?
>
> "forced" by Newton III?
>
> Mark
>
>
> Mark Sylvester
> UWCAd
> Duino Trieste Italy


Brian Whatcott    Altus OK    Eureka!