
When hypothesis becomes fact
by
ContraTory
on Sat 22 Apr 2006 22:53 BST
It is curious how certain hypotheses gain currency and quickly become accepted as an established fact, sometimes against the weight of evidence.
In the mid nineteen eighties I happened upon a BBC television programme examining the matter of heart disease. The earnest presenter, a doctor, adamantly asserted that the “fatty heart hypothesis” was not a hypothesis, but a proven fact. If you eat a fatty diet and don’t do any exercise, your arteries clog up and you die of a heart attack - plain and simple. It seemed a fairly sound argument to me. On the other hand I found his stridency jarring. Other experts thought they were possessed of evidence undermining the fatty heart “fact” and this irritated the presenter, who saw them as heretics.
A few years later, I happened upon another programme about a body that had been discovered in a glacier in the Alps. The body had been frozen intact, with the remains of clothes and some belongings. After examination by an assortment of experts, it was established that the individual had died about four thousand years ago. He had been almost certainly a nomadic shepherd. Forensic examination showed that he had not died of any illness nor had he been killed. It was believed that he had been caught in a sudden blizzard and died of exposure. Examination of his bones suggested that he was aged about forty years or so old.
It was possible to make a number of assumptions about his life style. The glacier in which his body was frozen and transported down to the lowlands over the course of four thousand years, started life high in the Alps, where until the last century there had still been a tradition of shepherds moving livestock up and down the mountains through the passing of the seasons. Thus he had not enjoyed a sedentary life style – it was not possible for him to have done so. He had never eaten processed or fatty foods. He had not been afflicted by any of the vices of soft, lazy, easy late-twentieth century living. Yet examination showed that his arteries had fatty deposits just like your average, overweight, unfit company executive. Oh well, it's back to the drawing board.
I was reminded of this when a number of scientists, who had been routinely ignored for years, published an open letter challenging the orthodoxy of “global warming”. It was then disclosed elsewhere that the purportedly inevitable, inexorable increase in global temperature had fizzled out in 1998. The global warming theorists may yet be proved to be right. Then again, they might be shown to be as misguided as flat earthers.