Who Will Debunk The Debunkers?
In 2012, network scientist and data theorist Samuel Arbesman published a disturbing thesis: What we think of as established knowledge decays over time. According to his book The Half-Life of Facts, certain kinds of propositions that may seem bulletproof today will be forgotten by next Tuesday; ones reality can end up out of date. Take, for example, the story of Popeye and his spinach.
Popeye loved his leafy greens and used them to obtain his super strength, Arbesmans book explained, because the cartoons creators knew that spinach has a lot of iron. Indeed, the character would be a major evangelist for spinach in the 1930s, and its said he helped increase the greens consumption in the U.S. by one-third. But this fact about the iron content of spinach was already on the verge of being obsolete, Arbesman said: In 1937, scientists realized that the original measurement of the iron in 100 grams of spinach 35 milligrams was off by a factor of 10. Thats because a German chemist named Erich von Wolff had misplaced a decimal point in his notebook back in 1870, and the goof persisted in the literature for more than half a century.
By the time nutritionists caught up with this mistake, the damage had been done. The spinach-iron myth stuck around in spite of new and better knowledge, wrote Arbesman, because its a lot easier to spread the first thing you find, or the fact that sounds correct, than to delve deeply into the literature in search of the correct fact.
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All these tellings and retellings miss one important fact: The story of the spinach myth is itself apocryphal. Its true that spinach isnt really all that useful as a source of iron, and its true that people used to think it was. But all the rest is false: No one moved a decimal point in 1870; no mistake in data entry spurred Popeye to devote himself to spinach; no misguided rules of eating were implanted by the sailor strip. The story of the decimal point manages to recapitulate the very error that it means to highlight: a fake fact, but repeated so often (and with such sanctimony) that it takes on the sheen of truth.
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http://fivethirtyeight.com/features/who-will-debunk-the-debunkers/