Re: Large animal extinctions: extinction-ex-astra

p3voices (
Fri, 05 Jul 1996 21:20:16 -0400

p3voices writes:
>comets, cometary nuclei, stony meteors, iron meteors, meteor swarms, small black
>holes (as in Tunguska), etc. The newest extinction-ex-astra fad seems to be,
>(after the comet impact on Jupiter), multiple comet/meteor impacts.

Timo Noruma writes:
2. You list what actually happens in our solar system. With one error.
The Tunguskan
explosion was not caused by a small black hole, but by a very common type
of stony

p3voices responds:
Of course i understand that the Tungukan event was not a small black hole
- I was mainly trying to show how far some people can go in trying to fit
an event to their favorite cause. This black-hole explanation became a
favorite fad in the late 1970's as I remember, with even some respectable
astromers/physicists supporting it. It died when Hawkings showed that
black holes have a "vapor pressure" due to the Heisenberg uncertainty
principle, and will slowly loose mass over time. Because of this, there
should no longer be any mini-black holes surviving the Big Bang (By the
way, I am not trying to imply you believed the black hole explanation
either - I never did either!)

There is an excellent discussion of the Tunguska event in Sky and
Telescope about 4 months ago. There still is a lot of debate over what
caused it, with a "loose" stony meteorite or a small cometary fragment/
nucleus being leading contenders.