Message-Id: <v01540b00b054fb6f6308@[12.64.1.226]>
To: pinhole@exploratorium.edu
From: kstreet@worldnet.att.net (Karen Street)
Subject: Re: half lives
Date: Mon, 29 Sep 1997 14:00:42 +0000
Ellen,
Another interesting half-life question: why are there any radioactive atoms
on Earth? After all, we are made from material that made in supernovas, the
latest of which occurred more than 2 By before the solar system formed,
more than 7 By ago!
Do supernovas make any atoms larger than uranium? We see no naturally
occurring trans-uranium elements on Earth.
If it weren't for the uranium in the Earth, the core would be solid.
Best wishes,
Karen