Supernovae and the Rise and Fall of Man

For the past few decades, there has been a lot of speculation, and
some proof, that things in or from the heavens can and do radically
and materially affect things here on Earth. It was around 1980 that
Luis Alvarez tied the extinction of the dinosaurs to the impact of a
sizeable asteroid striking the Earth about 65 million years ago. Now
another, more recent sequence of events has come to my attention, and
I thought I would share this with those who have an interest.

For the past week or so, I have been reading "The Cycle of Cosmic
Catastrophes: How a Stone-Age Comet Changed the Course of World
Culture" - by Richard Firestone, Allen West, Simon Warwick-Smith. The
authors attribute the extinction of the wooly mammoth, and other north
american megafauna, and the paleo-american Clovis culture, to a
probable comet strike at what is now Lake Michigan.

All of this began, they propose, when a supernova exploded about 70
parsecs away, some 41,000 years ago. The initial flash of radiation
killed many people, animals and plants outright, in the areas of
Australia and southeast Asia. Of course, many more died of acute
radiation poisoning shortly thereafter. And while most of the induced
genetic mutations were harmful, the authors note that it was shortly
after this event that mankind developed larger brains, and made huge
strides in technology and culture. There was a related reduction in
the human population, and several large species in Australia went
extinct.

About 7000 years after the supernova flash, the material shockwave hit
the solar system. This weakened the earth's magnetic field, disrupted
the ozone layer, and caused massive solar flares. This increased the
exposure to ultraviolet and cosmic radiation, again resulting in
reduced population and more species going extinct.

Finally, about 13000 years ago, one of the comets which had been
knocked into the inner solar system, came crashing down to earth. The
impact, or arial explosion wiped out millions of animals and people in
North America, set grasslands and forrests ablaze, dislodged and
melted the ice sheet that was over the northern part of the contenent,
and debris splashing into the ocean started tsunamis that ravaged the
coasts of Europe and Africa.

Perhaps the most distrubing conclusion that these authors derive, is
that while the human race owes its swift rise to this supernova
(killing off competing predators, giving us larger brains, etc.) we
are still imperilled by its consequences. There are two factors that
they cite:
1. Our success has led to overpoplulation (which has led to the
current slew of problems we face globally). And the overpopulation is
always a temporary state, usually accompanied by a swift and
unavoidable depopulation.
2. The Earth is under greater meteor and comet bombardment now than we
were a billion years ago. It is nearly as high now, as when the
dinosaurs disappeared.


So, the next time you are out under the stars, contemplating the
serene beauty of the heavens, take heed that they may harbor both
terror and death as well.

Cheers,
Larry G.