From: utzoo!decvax!harpo!gdw Newsgroups: net.space Title: Re: Equivalence of Mass and Energy - (nf) Article-I.D.: harpo.933 Posted: Mon Aug 9 10:16:08 1982 Received: Tue Aug 10 00:58:40 1982 #R:phs:-64800:harpo:11700002:000:259 harpo!gdw Aug 9 09:59:00 1982 I'm lost! I thought 4 hydrogen atoms do have MORE mass than a helium atom. That is how hydrogen bombs work, isn't it? So perhaps those arguing the mass issue could be more specific; are we talking rest mass or "dialated" mass if the helium is more energetic?