Archived posting to the Leica Users Group, 2000/01/28
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Alas, I did not study nuclear physics like my parents hoped I would but I have come into a smattering of knowledge on the subject. 14 billion years is a long time to wait for your dog to come back from a walk or, perhaps, for your true love to come around; but, not such a long time for an element. There are elements with half lives much much shorter than our present guestimate of the universe's age (so short we had to make them to find them) and more are being discovered in the spooky, long (very long) corridors of mass accelerators. Radioactivity is defined as: "the property of spontaneous disintegration of atomic nuclei usually with emission of penetrating radiation or particles" (Oxford). For any given mass of material, the more of it that breaks down over a set period, the more radiation or particles are emitted. A "half life" is the period of time in which half of a given quantity of an element will break down. So if you squeeze the three above statements together you will realise that the shorter its half life, the more radioactive an element will be. I have noticed this in human nature as well; the shorter the low-life, the more trouble they are! As an interesting aside elements can break down through a whole series of stages before they become stable and at one time it was possible for enough fissile material to gather through natural processes for spontaneous nuclear explosions. Neat. You know what they say about the good old days. And finally elements do not particularly cotton to the saying: "a life half lived is not worth living at all." John Collier > From: "Mike Gil" <pasuno@hotmail.com> > Date: Fri, 28 Jan 2000 09:00:59 PST > Subject: Re: [Leica] Radiation and half lifes > > Of course this statement is false, its the other way around, the shorter a > radioactive element takes to decay the less radioactive it is. A 13 billion > year half life is a very long time for something.