Re: [Phys-l] The flow of energy

[Leigh Palmer <palmer@sfu.ca>]

On 14-May-06 Jack Uretsky wrote:

> Hi all-
> 	I think that Leigh's recounting of history is highly inaccurate.
> 1.  I know of no process that violates strict conservation of  
> momentum.

That's because you don't have a nineteenth century point of view.

> 2.  My understanding (we can find the original papers) is that  
> serious consideration was given to explaining the continuous  
> electron spectrum in beta decay as a violation of momentum  
> conservation.  Fermi (I believe it was) then produced the neutrino  
> hypothesis which was confirmed experimentally by Reines and Cowling  
> [sic].

Reines and Cowan put an end to the perplexity decades after Fermi  
made his suggestion.

> Today we are blessed with 3 varieties of neutrino, at least two of  
> which are massive.  The discovery
> of radioactivity therefore certainly is not, as Lee [sic] seems to  
> suggest, an indication that physicists should doubt conservation of  
> momentum.

The definition of momentum has been changed in the past. I am  
suggesting that it may be changed yet again in the future. Do you  
disagree?

> 3.  Labeling "momentum" an "abstract quantity" is not very  
> meaningful, and leads to no experimental consequences - at least  
> not without a precise definition of the adjective "abstract" which  
> can have a variety of meanings.  Momentum is a very concrete  
> quantity in the sense that it is measurable, and momentum flow is  
> measured in high-energy collisions at Fermilab and elsewhere.
> 				Regards,
> 					Jack

Leigh