Forces and Motion

Weighing the soul

Stories from Physics for 11-14 14-16 IOP RESOURCES

The Boston physician, Dr Duncan MacDougall, carried out one of the strangest mass measurements ever performed, reported in a paper published in 1907. MacDougall measured the mass of six patients before and immediately after their deaths and recorded mass difference of between 8 and 35 g. In a similar experiment with dogs, no difference in mass was detected, which was explained by the assumption that dogs have no soul. Later work, by a Swedish psychiatrist, established a figure of around 21 g for the mass of the soul.



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