[geocentrism] Re: Angular momentum
- From: Mike <mboyd@xxxxxxxxxxxx>
- To: geocentrism@xxxxxxxxxxxxx
- Date: Fri, 22 Oct 2004 08:42:57 +0100
Dr. Neville Jones wrote:
> Mike,
>
> Rather than my arguments being circular, it is you who
> are continually switching between linear and angular
> momentum. Using linear when it suits you, to try and
> justify your contention that angular is relevant to a
> gaseous "body."
If you look at the definition I quoted you will see that angular
momentum is defined in terms of linear momentum. At first I thought you
were only questioning conservation of angular momentum but it transpired
that you disagree with linear momentem too thus bringing it into the
discussion.
I notice you haven't actually addressed the point that you used a
simplified definition with limited applicability and simply demonstrated
that it doesn't apply outside of that limit.
> I was pleased to see that you said, "Maybe [your] use
> of the word "any" in [your] previous post was a little
> strong."
I'm not sure in what systems it does not apply, when physicists use
words like "most" without qualification they usually mean "just about
any". It doesn't necessarily apply if there are non-central forces
involved. It certainly does apply when considering gravity, friction,
and paricle collisions.
> Whilst I appreciate the time and trouble you went to
> to give the group the online encyclopedia reference, I
> must point out that such sources of information have
> to be appreciated as to the scope of audience they are
> geared for.
It was no trouble, there are numerous sites that give exactly the same
definition. I have been trying to keep the conversation at a basic
level because you and I disagree at a basics level. You gave me no
choice but to give the definition because of your insistance on using a
simplified definition that only applies to objects spinning around a
common axis and your insistance on claiming it was *the* definition.
And incidentally, you refused to answer my questions about two rotating
rigid bodies in friction and instead wrote a long post regarding thermal
activity etc. You also side stepped my question regarding a single
rigid rotating body in a vacuum. We've basically had to go the long way
round to get back to these basics that you disagree with.
>>> 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?
>
> According to me, definitely, but also according to
> anyone who delves deeply enough into this.
Well please give me some links so that I can delve. I can't find any
mention of loss of momentum (linear or angular) due to inelastic
collisions anywhere.
>> I think your contention that a rotating earth
>> would necessarily slow to halt due to atmospheric
>> friction boils down to this above statememt.
>
> Yes, I agree, it does boil down to this.
So we can dispense with angular momentum for now and just talk about
conservation of linear momentum in inelastic collisions. Once we reach
agrement we can move on to angular momentum remembering that it is
defined in terms of linear momentum.
>>You are still confusing kinetic energy with angular momentum. Inelastic
>> collisions result in a decrease in *kinetic energy*.
>>
>>I think it would be helpful here if you clarify which bit of
>>conventional physics you disagree with.
>
> I thank you for stimulating my thoughts on this,
> because I have today been drafting another page for
> the website. This is turning (pardon the pun) into a
> VERY important point.
Indeed, in the list I gave it appears that you depart from conventional
physics at number 1. Rather than just stating that you disagree with it
you should really develop it further, either show us where conventional
physics agrees with you on this or show us how conventional physics is
wrong on this matter.
Regards,
Mike.
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