No vampires

Just in time for halloween comes this “back-of-the-napkin math”:http://lefarkins.blogspot.com/2006/10/so-what-about-chupacabra.html disguised as academic paper proving there are no vampires:

bq. Let us assume that a vampire need feed only once a month. This is certainly a highly conservative assumption given any Hollywood vampire film. Now two things happen when a vampire feeds. The human population decreases by one and the vampire population increases by one [ ... ] we will ignore the human mortality and birth rate for the time being and only concentrate on the effects of vampire feeding.

There follows a chart demonstrating that human population — based on the population of the 1600s — would be converted to vampires in thirty months.

Now, obviously this is not intended to be particularly serious. But clearly this is far from rational argument. As is noted in the comments, vampires do not _necessarily_ create vampires with every fresh kill. In fact, in many of the classic works suggest that one vampire might make many visits to the same individual, keeping him or her alive the way as a kind of milk cow. There is also a strong literary tradition of “sharing” among vampires, where many vampires might share one individual.

Also as noted in the comments, vampires are reasonably intellegent and could be expected to take steps to prevent the food supply from reaching crisis stage. The vampires from Exxon/Mobil excepted, of course. Personally, I think if everytime *I* ate my food came back to life and started trying to cut the buffet line, I’d keep some spare stakes handy.

Oh, and the model doesn’t consider the effect of Wesley Snipes, who can convert hundreds of techno-dancing eurotrash vamps into digital ash without breaking a sweat.

As silly as this particular argument is, it does call to mind many of the so-called “rational” arguments againt non-scientific belief — thought experiments where speakers assume existence or non-existence of phenomena can be determined without putting down their beer.