Rolled Out On: 12/1/2006 1:17 PM

The detail I remember most about Tunguska, from a Russian SF story which postulated a UFO accident, was that the trees at the center of the devestation remained standing. I cannot conceive how a black hole would generate an airburst.

Rolled Out On: 12/1/2006 1:49 PM

Dr. Adler explains it the best

But what about that forty-megaton explosion? Seems like, if Vurdalak [this is the name given to the PBH and means Vampire in russian -SaaM] was too small to have produced Burns and company’s thermal and seismic effects, it’d also have been way too small to kick up much of a fuss when it hit. It’s for sure it couldn’t’ve flattened and burned all the trees — 80 million of them according to the latest estimates! — across an area half the size of Rhode Island. It couldn’t’ve burned the shirt off the back of a man standing forty miles away. It couldn’t do all that, now could it?

Turns out it could. Because, remember: Vurdalak’s dragging all that ionized air along with it, sweeping up more and more of it the further it goes. Hundreds of thousands, maybe millions of tons of it, by the time the hole traverses the four, five hundred miles of atmosphere along its shallow-angled approach path.

Now, imagine what happens when Vurdalak hits. By itself, it’s not going to have much effect outside a couple meters radius. But then this faster- than-sound hurricane comes hammering down behind it. A mountain of air piles up, compresses, heats. A gale-force superhot wind blows outward in all directions from the epicenter, flash-burning the bark off the trees even before they have time to fall, leaving nothing but smoldering ruination behind.