Civ I don't know if you noticed, but the supernova/gamma ray burst/cosmic bombardment association seems to have disappeared -- or has it?Some years ago, there was a book in which the author put forward a model for K-T extinction due to supernova; I tried to get into it, but didn't find it compelling. I don't recall the author's name or the book's title, or anything that would be useful for this anecdote. Nuts.
The ORIGINAL ARTICLE(w/Topping) made several references to the liklihood(?) of a hit from a supernova. Conspicuously missing from the article cited for this thread along with another theory; that is, carbon dates, particularly associated with paleoindian dates, were quite possibly much too young -- by about 40,000 - 50,000 years. I gather that theory has been abandoned. Which MAY be why Topping is back in the references and cites in the article on THIS thread?