[net.space] mass vs. energy

rhm (08/07/82)

This is a sample of recent mail.  I am *almost* at a loss for words.
I suppose I could continue pointing out there is no loss of mass
(and by the way no change in center of gravity, despite assymetries)
during a supernova explosion, ad infinitum.

Others will insist that, despite Einstein, mass is not
equivalent to energy and that the notion of mass is identical to
the notion of rest mass, and that the energy of a photon is not
"really" mass for some unspecified reason......

    From harpo!duke!phs!jfh Sat Aug  7 13:21:31 1982
    Date-Sent: Sat Aug  7 11:35:16 1982
    To: duke!harpo!floyd!rhm
    Subject: Re: floyd.426: Re: Supernova, Gravity, Etc

    	Surely you jest!!  Photons have NO mass.  If this were not true,
    then they could not travel at the speed of light.


    						Fran Heidlage
    						duke!phs!jfh