[geocentrism] Re: Angular momentum
- From: Mike <mboyd@xxxxxxxxxxxx>
- To: geocentrism@xxxxxxxxxxxxx
- Date: Thu, 21 Oct 2004 03:48:16 +0100
Dr. Neville Jones wrote:
> Mike wrote,
>
>> I urge you to learn up on some basics physics before claiming it is
>> inconsistent with the acentric model."
>
> What you really mean is that you urge me to propound the conventional
> explanation for a "phenomenon" that I do not accept. I have provided
> this group, I think, with the physical basis for my non-acceptance
> (not just the Biblical basis).
Your argument, if you'll excuse the pun, was completely circular. You
started with a simplistic definition of angular momentum that only
applies to rigid bodies with a common axis of rotation and then
proceeded to demonstrate how it breaks down for fluids. If you are
going to claim that the conventionally given definition of convservaton
of angular momentum breaks down for fluids and therefore can't account
for the earth's continued rotation then surely you must start with the
conventially given defintion.
Here are your words:
> As I have said many times now, angular momentum is an attribute of
> rigid bodies. That is how it is DEFINED. Note that ALL the particles
> within a rigid body have the SAME angular frequency about a COMMON
> axis of rotation, irrespective of how far each of them is from that
> axis. Angular momentum does not apply to gases, nor, in general, to
> fluids."
Note that you said "That is how it is defined" and then said "Angular
momentum does not apply to gases..." - the implication being that *by
definition* it does not apply to gases.
Here's some words from
http://encyclopedia.thefreedictionary.com/Conservation%20of%20angular%20momentum
> The traditional mathematical definition of the angular momentum of a
> particle about some origin is:
>
> L=r x p
>
> where L is the angular momentum of the particle, r is the position of
> the particle expressed as a displacement vector from the origin, and p
> is the linear momentum of the particle. If a system consists of
> several particles, the total angular momentum about an origin can be
> gotten by adding (or integrating) all the angular momenta of the
> constituent particles."
Note the word "some" in the first sentence. It goes on to say:
> What's more, this conservation can be generalized to a system of
> particles under most conditions"
Maybe my use of the word "any" in my previous post was a little strong.
It also says:
> For many applications where one is only concerned about rotation
> around one axis, it is sufficient to discard the vector nature of
> angular momentum, and treat it like a scalar"
You may not agree with the definition but is that definition you need to
use if you are to show that conventional physics is inconsistent with
a rotating earth.
>> Elastic or not, every action has an equal and opposite reaction. Are
>> you now saying that linear momentum isn't conserved when two
>> particles collide?
>
> It is not conserved in an inelastic collision, no.
Are you saying that according to convetional physics it is not conserved
or just according to you? I think your contention that a rotating earth
would necessarily slow to halt due to atmospheric friction boils down to
this above statememt.
You are still confusing kinetic energy with angular momentum. Inelastic
collisions result in a decrease in *kinetic energy*. Nearly elastic
collisions (like billiard balls) lose less kinetic energy. Elastic
collisions (atoms, molecules, subatomic particles) lose *no* kinetic
energy. But they all conserve angular momentum.
> Furthermore, any collision between billiard balls is inelastic.
I never said they were. But they are *nearly* elastic so they're useful
in demonstrating the conservation of momentum because the kinetic energy
takes a while to disapate.
I think it would be helpful here if you clarify which bit of
conventional physics you disagree with.
1. Newton's laws of motion (usual quantum and relativity caveats apply)
2. The derivation of the law of conservation of angular momentum from
Newton's laws
3. The application of the conservation of angular momentum to the earth
and atmosphere.
Somtimes you seem to be saying no. 1 and sometimes you seem to be saying
no. 3. In 2. I am of course assuming we stick to central forces. Your
argument is about friction which boils down to kinematics.
Regards,
Mike.
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