Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site alberta.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!ihnp4!alberta!andrew From: andrew@alberta.UUCP (Andrew Folkins) Newsgroups: net.astro.expert Subject: Re: Forming The Elements Message-ID: <571@alberta.UUCP> Date: Thu, 27-Jun-85 19:36:39 EDT Article-I.D.: alberta.571 Posted: Thu Jun 27 19:36:39 1985 Date-Received: Wed, 3-Jul-85 09:02:13 EDT References: <243@ihnet.UUCP> Reply-To: andrew@pembina.UUCP (Andrew Folkins) Distribution: net Organization: U. of Alberta, Edmonton, AB Lines: 34 Summary: In article <243@ihnet.UUCP> eklhad@ihnet.UUCP (K. A. Dahlke) writes: >< H He C N O Si Fe > > A recent scientific American article (May i believe) >described the explosion of a super nova. >My question is, how did the other elements form; >especially those above iron? The elements up to iron are created by a process called nucleosynthesis, in which smaller atoms fuse together to produce larger ones. The fusion of elements up to iron produces energy, while the fusion of atoms heavier than iron absorbs energy. Thus, silicon fusion will produce enough energy to keep the star going (for a day or two, I think the figure was), while iridium fusion would suck up energy and cause the star to collapse under it's own weight (it's normally supported by radiation pressure from the fusion processes in the core). Elements heavier than iron require extra energy to produce, energy not normally present in the core of a star. The energy is found, however, in supernova explosions, where the temperatures and pressures of the collapsing core are sufficient to produce the remaining natural elements. When the core rebounds, producing the actual explosion, some of these 'impurities' are blasted out into space, where, after billions and billions of years, they condense to form ingots in bank vaults :-). I think I'll go re-read that article, it _was_ quite interesting. -- Andrew Folkins ihnp4!alberta!andrew Underlying Principle of Socio-Genetics : Superiority is recessive.