Warp wrote:
> Warp <war### [at] tagpovrayorg> wrote:
>>   Besides, we can just forget the cable: Simply shoot the projectile and
>> that's it. With the correct amount of speed it will stop the object from
>> rotating. Where did the angular momentum go?
> 
>   I thought about this and became to a conclusion. You could have explained
> it if you knew it instead of just saying "you are wrong" without any
> explanation.
> 
>   The answer is that the object-projectile system still has the angular
> momentum. If we calculate the angular momentum of this system after the
> firing, ie. the how the system is oriented with regard to the center of
> mass of the system and the distance between the two objects, we will
> probably get an angular momentum equivalent to the original one.
> 
>   The same is probably true for two approaching objects which collide.
> Even though each object by itself didn't have any angular momentum, the
> two-object system did. The entire two-object system is actually rotating
> around the center of mass of the two objects (even though they two objects
> are travelling almost rectilinearly; this is because they are not travelling
> along the same line in space). When they collide and stick to each other,
> the "speed of rotation" they had just before they collided will be kept. The
> angular momentum will be unmodified. Only if the two objects were travelling
> exactly on the same line in space will there be no rotation because there's
> no angular momentum.
> 
Several times, as carefully as I could I explained that angular momentum 
is conserved in a closed system.  That is a general principle that is 
apparently fundamental to the way the universe works.  Apart from 
stating the principle which you will find in any physics textbook that 
touches on the subject and on many websites, I also explained as 
carefully as I could in this medium where the angular momentum was 
transferred from and to in several examples.

Sorry but you continued to assert that friction could cancel out angular 
momentum and that a spinning closed system could be brought to rest 
without any external force.

When I asked plainly is angular momentum conserved in a closed system 
you replied:

 >>Angular momentum can be lost by converting it to heat (or other forms
 >>of energy for that matter), so the answer is no, unless you don't 
 >>consider it a "closed system" anymore if there's heat dissipation 
 >>(OTOH, this heat could theoretically be collected and stored, keeping 
 >>the whole thing a closed system).

I'm still unclear from your other posts as to whether you still maintain 
this position.  Perhaps you have taken some time to research the facts 
and would recant your statement?

I'll admit to being a poor instructor.  I think you have to admit to 
being a) wrong and b) pig-headed about it.

I will reply to your other posts to try to clear up some of the wrong 
assertions that you continue to make in them.  It would be nice if you 
could reply in one coherent go though rather than in dribs and drabs of 
silliness.

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