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Re: Extinction scenarios
Tom Hopp wrote:
> As I recall, the writer pointed out that the hypersonic expansion of > gasses
> would create a massive pressure wave capable of propagating > for great
> distances (going fastest and farthest in the denser > atmosphere at sea
> level). As elementary physics class tried to > teach us, if you
> compress a gas, without adding heat, it will still > heat up, due to the
> increased rate of molecular collisions when > density is increased.
> Thus, a propagaing pressure wave will heat > the atmosphere as it passes,
> then the air will return to its > original temperature after the
> pressure wave is gone.
> The thing is (and I just MIGHT be the first to state this) the >
> unfortunate coincidence of a large bolide hitting a shallow sea over > deep
> carbonate rocks might have created an impact unique in the > magnitude
> of its shock wave. Undoubtedly, the shock wave would be > strong enough
> near the impact to create the white-hot flash that > Alvarez and others
> have mentioned, but it seems to me that the > PROPAGATING SHOCK WAVE,
> if big enough, would have also heated air to > white-hot temperatures. The
> question is: over how great a distance > could this wave carry lethal heat?
> My personal bias is: ALL THE WAY > 'ROUND THE WORLD.
> Thus, you might be a Muttaburrasaurus quietly sipping at a watering > hole in
> Australia, far from the impact, when the first thing you > noticed was
> that you were hurtling through the air amid white heat. > This of course,
> would be your closing observation on conditions in
> the Late Cretaceous.
While I would certainly not deign to argue the physics described above,
I do have to ask (as Peter Buchholz already has), how did *anything*
survive this doomsday scenario you've postulated? Seems to me that this
level of catastrophe would pretty much wipe the Earth clean of *all*