I was very impressed by your opening overview of the Tunguska event, in particular your detailing of the scientific observations made at the time.  How much of your total time during your Singularity effort was spent on Tunguska research and related black-hole items?  How much of this was source material that has been catalogued on the web, and how much is from good-old-fashioned library research of books and papers?  What have you found are the best sources of historical record for this important scientific event, which exists independently of your rippin' good yarn?  Any estimate of how much good source material probably remains untranslated into English?

Also, bottom line, do you really truly believe yourself the Jackson-Ryan black-hole hypothesis caused Tunguska?  I guess my own belief is that is was a loosly compacted / low density / gravel pile meteorite to explain the lack of a ground zero blast crater.  If you don't think that's the cause, what is the main evidence against it?

Enjoy reading this SciScoop story? Here's a thousand more.

My first thoughts were that it was a coincidence almost past the boundary of my ability to suspend disbelief that the object's orbit around Earth's center of mass was meshing so nicely with Earth's revolution. But then I thought about the magnetic monopole aspect of the object. Your book has a great description of monopoles by the way - how the magnetic field lines stick out like a koosh-ball! Anyway, so I realized that the object's orbit would also be influenced by the Earth's magnetic field. I'm not sure what the influence would be. Do the Earth's magnetic field lines revolve with it around the axis? If so, that might explain why the object seems to follow along with the earth's surface.

And that got me to thinking, gee whiz, maybe that's why the Tunguska object hit the ground in Siberia. If it was a magnetic object, might it have done like all the charged particles do when they approach the Earth? That is, charged particles' paths curve along the lines of the Earth's magnetic field, get channeled to either the South Pole or the North Pole, and they end up as a pretty aurora show. Could this be the reason that the Earth was struck way up there at 62 degrees latitude and not someplace closer to the equator?

I kinda read over the vurdalak.com website and I take it that "Dr. Jack Adler"'s "Vurdalak Conjecture" is that the Tunguska object was a primordial-black-hole-magnetic-monopole. Question 1: Is this "Dr. Jack" a real person? (Do you think you could get him to stop by SciScoop?) Did you get the primordial-black-hole-magnetic-monopole idea from him?

Question 2: do you recall from your research exactly how the exit point of the Jackson-Ryan hypothesis was determined? Is there physical evidence that the object came at the angle that would take it straight through to the mid-Atlantic, or is this based on eyewitness accounts of the angle of the sky trail, or what? Wouldn't the exit wound be in a different place if the object was magnetic? (Due to the Earth's magnetic field influencing its path through the Earth?) Possibly near the South Pole even, where the population is sparser than Siberia's? (Or, as you say, what if it never came out at all!)