Photon Mass?

[R.G. Walters]

In article <sib-0809941303350001 at biomed-jww-245.biomed.brown.edu> sib at brown.edu (Sam Beale) writes:
>In article <f_holleyg-080994084705 at holley.sfasu.edu>,
>> Does a photon have mass or is it just an energy wave?
>
>No mass, all energy.  They travel at the speed of light.  This alone
>disqualifies them from having mass.  Said another way, if they had mass
>and travelled at the speed of light, they would have infinite energy. 
>Consult any physics book.

But they DO have momentum.  Again, consult a physics book :-)

Robin Walters.                      Robert Hill Institute, Sheffield UK.

A fact is an opinion that everyone agrees with.