A recent American film—21 grams—made the assertion that at the precise moment of death each of us loses 21 grams of weight. My curiosity was aroused by this startling claim. Given that more than 2 million Americans claim to have been abducted by aliens at some stage in their lives, I assumed that this rather extraordinary statement was simply more American bunkum.

Believe it or not, such an experiment was actually carried out. In 1907, Duncan MacDougall MD of Haversham, Massachusetts performed a series of extraordinary experiments on dying patients. ¹ He reported six …