🚀 go-pugleaf

In article <4bbqu6$r2q@marina.cinenet.net>, vergon@cinenet.net (Vertner
Vergon) wrote:

> Ross Tessien (tessien@oro.net) wrote:
> : In article <4b6p20$bm7@scotsman.ed.ac.uk>, ajc@reaxp01.roe.ac.uk says...
> : >
> : >In article <4b6nep$gu3@ixnews2.ix.netcom.com>,
> : >Alan \"Uncle Al\" Schwartz  <uncleal0@ix.netcom.com> wrote:
> : 
> : Now the energy imparted by a photon colliding with the black side of the 
> : surface and being absorbed is one times its momentum.  This is given by 
> : its relativistic mass times velocity, or, U = mc
> 
> Then you agree, a photon that has mometum has mass.
> 
> That's where this whole subject of radiometers started.
> 

Get of your hobby horse for once! It was well understood long before 1900,
starting with Maxwell, that electromagnetic waves carry both energy and
momentun in the ratio E = c p.
No quantum mechanics, photons, mass, or relativity is needed here.

Best wishes,

Jan