[geocentrism] Re: Several posts
- From: Mike <mboyd@xxxxxxxxxxxx>
- To: geocentrism@xxxxxxxxxxxxx
- Date: Tue, 12 Oct 2004 23:53:36 +0100
Neville,
> Welcome back. You made some quite stiff comments when you left, but
> have been gracious enough to retract them. I think that says a lot.
> Thank you.
Thank you for getting straight back to the issues. I'm not proud of
myself when I lose my rag. We achieve nothing in conversation if we
allow ourselves to descend into insult. I was impressed by your
reasoned response to my rant. I stil stand by much of what I said but
wish I had said it differently. I'll leave it at that try to confine
myself to talking about your ideas which is why I'm here afterall.
> As for the law of the conservation of angular momemtum, this is one
> of those "laws" in physics which sounds very grand, but doesn't
> actually state anything other than the obvious. It is basically just
> the rotational equivalent of Newton's first law of motion.(that a
> body does not undergo a change in direction without a force acting
> upon it).
Indeed, that was my point.
> It applies to rigid bodies and, if the World were a sphere,
> spinning in a vacuum, then there would be some justification to what
> you say. However, the effect of the atmosphere en mass is to act as a
> couple. The law of the conservation of angular momentum, that the
> total angular momentum of a rotating system remains constant in the
> absence of any external torque,.is not relevant to the interaction
> between the solid and liquid World and its gaseous atmosphere.
If you claim this is standard physics then you are mistaken. I would
challenge you to supply links or references to support this claim. As
far as I understand conservation of angular momentum (CAM) applies to
any closed system. For the sake of the argument over whether or not the
earth and atmosphere can be rotating together you can consider them as a
closed system. The moon and sun do have a measurable effect and
actually slow the rotation of the earth down (while still conserving
angular momentum of the sun-moon-earth system) but your argument does
not depend on them anyway.
If you accept that what you said is contrary to conventional physics
then I would be interested in reading your elaboration of the point.
Like starting with two air molecules and treating them as rigid objects
(where I presume you agree with CAM) and then increasing there number,
adding some other molecuels that are clumped together rigidly and
showing where the point comes where CAM breaks down (in each case
keeping the system closed of course). Fluid dynamics is just a
statistical approximation of rigid body dymamics afterall.
> To illustrate: take the usual example of the spinning ice skater who
> folds her arms in and thus rotates faster. In a vacuum, she will spin
> forever (well, you know what I mean). However, in the presence of the
> air around her, what will happen?
She will slow down and impart here angular momentum on the air around
her in the process (like you I'm ignoring the friction of the ice skates
on the ice). Two objects spinning relative to each other with friction
will eventually come to rest w.r.t to each other and the energy will
dissapate as heat but both will slow in the opposite direction all the
while conserving angular momentum. I guess you agree with that anyway
as I'm talking about two rigid bodies but friction with the air is
exaclty the same, there's just so many more objects to consider that it
is only feasible to treat them all statistically.
Regards,
Mike.
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