His basic theory; one of them; was that a major planet passed close to the Earth and caused the Earth to reverse on it's axis, i.e. The North Pole became the South Pole and vice versa.

I believe, if memory serves me, that he theorized that it was a close pass by a comet which occurred at the time of the "Exodus" and extrapolated this theory to explain the parting of the Red Sea, the Pillar of Fire, and Manna from Heaven. This, of course is what got him into so much trouble.

What intrigued me was his references to Chinese and Incan texts from the same period in history which described huge earthquakes and tsunamis that decimated those populations. In the aftermath the Chinese Emporer sent out his astronomers to "recalculate the calendar" that they had used for centuries which had a year made up of 360 days. Modern historians just passed this off as bad math on the part of the ancient Chinese astonomers but obviously a calendar that was incorrect by 5 1/4 days a year would have you planting your spring crops in the middle of winter within a couple of decades.

The only other explanation would be that something pulled the Earth into a significantly farther orbit from the sun. It is easy to understand why scientists and historians have a hard time accepting the possibility that such a huge cosmic event could have taken place within the last 3000 years since we like to think of of these things as occurring millions or years in the past or millions of years in the future.

So if you see the Oort cloud coming - DUCK!