[net.space] Supernovas

KFL@MC.LCS.MIT.EDU ("Keith F. Lynch") (03/02/86)

  Supernovas are very rare events.  It is estimated that they happen
no more than once per century in a galaxy our size.  That is about ten
to the eleventh stars.  So any given star (such as Sirius) only has
about a one in ten to the thirteenth chance of going supernova in any
given year.
  Our galaxy has a volume of about ten to the fourteenth cubic
lightyears.  So the supernova density is about ten to the minus 16th
supernovas per cubic light year per year.  We can expect one every
2 thousand years within 10,000 lighyears, one every 2 million years
within 1000 lightyears, one every 2 billion years within 100
lightyears, and one every 2 trillion years within ten lightyears.
None of these except the last would hurt us.
  There are plenty of good reasons for going into space, but
supernovas aren't one of them.  Lets try to stick to realistic
reasons if we are going to preach to the not yet converted.
								...Keith