Paul Fuller wrote:
> 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. 

Well, it's not just random. All the "conservation" laws are based on 
"symmetry" laws.  Conservation of energy is based on the premise that 
what you do here will act the same as what you do there. Conservation of 
momentum follows from the idea that an experiment you do now will give 
the same results as an experiment you do later. Conservation of angular 
momentum is based on the premise that an experiment you do facing this 
way will give the same results as an experiment facing that way.

There are similar relationships in the quantum world like conservation 
of spin and so on.

I.e., it's not just that it happens to hold. We know *why* it happens to 
hold, and how to tell when we find a situation where it doesn't hold.

Which I personally find pretty cool to know. :-)

-- 
   Darren New / San Diego, CA, USA (PST)
     Remember the good old days, when we
     used to complain about cryptography
     being export-restricted?

Post a reply to this message