Re: law of conservation

[Inge H A Pettersen <ingep@online.no>]

I have the following questions:
	1)	Does it make sense in the classical GR context
		to talk about gravitational energy in general (or
		just for just special spacetimes)?
	2)	How is the corresponding situation for angular
		momentum and linear momentum in classical GR ?
	3)	In newtonian physics conservation laws are connected
		to symmetries (Noethers theorem) and appropiate
		boundary conditions. Is it possible to make statements
		about existence or absence of conservations laws (energy,
		linear momentum and angular momentum) according to 	
		symmetries of spacetimes and their corresponding boundary 
		conditions (asymptotic flat ect.)?
Bob Sciamanda wrote:
> Bill,
> This statement may be vague enough to be true, depending on just what is
> meant by "significantly different properties".  Can you be specific as to
> just what other connotations you necessarily include in the word
> "conserved"?
>
> (We are going to the heart of grave, unspoken misconceptions which our
> teaching language fosters - we are wont to speak of energy as if it were
> a tangible "thing".)
>
> Bob Sciamanda
> Physics, Edinboro Univ of PA (ret)
> trebor@velocity.net
> http://www.velocity.net/~trebor