21 grams

In 1907, an American scientist by the name of Dr Duncan Macdougall carried out a series of experiments on patients in a hospital in Massachusetts. Six terminally ill patients were placed on a special weighing machine that MacDougall had invented to discover whether there was any decrease in weight at the precise moment of death.

After the poor buggers passed away, MacDougall noted that, in each case, there was an 'inexplicable loss of weight of three-fourths of an ounce' or 21.3 grams.

To add weight to his discovery, MacDougall also monitored five poorly pooches. When the dogs died there wass no decrease in weight, leaving the scientific community to conclude that either

i) the human soul really does weigh a little over 21 grams, or
ii) dogs are soulless bastards bent on world domination and bringing mankind to heel.

Fact or fiction? You decide.