From: utzoo!decvax!duke!harpo!floyd!rhm Newsgroups: net.space,net.physics Title: Re: Equivalence of Mass and Energy Article-I.D.: floyd.429 Posted: Sun Aug 8 22:19:39 1982 Received: Mon Aug 9 05:09:07 1982 O.K. I will reply specifically to duke!phs!jfh 1. If four hydrogen atoms conspire somehow to form a helium atom, then the mass of the helium is exactly that of the hydrogen atoms. 2. Mass and energy are the same. 3. Yes, the mass of a collection of particles increases if they are heated. 4. Energy exerts gravity. Altogether, rest mass doesn't have much do with anything. These positions may or may not be defensible, but I will let any physics text do the defending for me. They are hardly disputed questions.