Genius_ The Life and Science of Richard Feynman - James Gleick [257]
On the crucial question of the effect of temperature on O-ring safety, NASA had made an obvious statistical blunder. Seven flights had shown evidence of damage. The most damage had occurred on the coldest flight—at a still-mild 53 degrees Fahrenheit—but no general correlation could be seen between temperature and damage. Serious damage had occurred at 75 degrees, for example.
The error was to ignore the flights on which no damage had occurred, on the basis that they were irrelevant. When these were plotted—seventeen flights at temperatures from 66 to 81 degrees—the effect of temperature suddenly stood out plainly. Damage was strongly associated with cold. It was as if, to weigh the proposition that California cities tend to be in the westernmost United States, someone made a map of California—omitting the non-California cities that would make the tendency apparent. A team of statisticians formed by the National Research Council to follow up the commission report analyzed the same data and estimated a “gambling probability” of 14 percent for a catastrophic O-ring failure at a temperature of 31 degrees.
Feynman discovered that some engineers had a relatively realistic view of the probabilities involved—guessing that a disaster might occur on one flight in two hundred, for example. Yet managers had adopted fantastic estimates on the order of one in a hundred thousand. They were fooling themselves, he said. They cobbled together such numbers by multiplying absurd guesses—that the chance of a turbine pipe bursting was one in ten million, for example.
He concluded his personal report by saying, “For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.” He joined his fellow commissioners for a ceremony at the White House Rose Garden. Then he returned home, as he now knew, to die.
EPILOGUE
God forbid that we should give out a dream of our own imagination for a pattern of the world.
— Francis Bacon
Nothing is certain. Werner Heisenberg wrote this message in the twentieth century’s consciousness. The mathematician Kurt Gödel followed with a famous proof that no logical system can ever be consistent and complete. The possibilities of true knowledge seemed to fade.
Heisenberg formulated his uncertainty principle narrowly: A particle cannot have both a definite place and a definite momentum. Still, philosophers took note. The implications seemed to cover a broader territory than the atom and its interior. Yet Feynman scorned philosophers (“rather than embarrass them, we shall just call them ‘cocktail-party philosophers’”) who overinterpreted the laws of physics by saying, for example,
“That all is relative is a consequence of Einstein, and it has profound influences on our ideas.” In addition, they say, “It has been demonstrated in physics that phenomena depend upon your frame of reference.” We hear that a great deal, but it is difficult to find out what it means… . After all, that things depend upon one’s point of view is so simple an idea that it certainly cannot have been necessary to go to all the trouble of the physical relativity theory in order to discover it.
Einstein’s relativity did not speak to human values. Those were, or were not, relative for reasons unrelated to the physics of objects moving at near-light speed. Borrowing metaphors from the technical sciences could be a dangerous practice. Did the uncertainty principle impose its inevitable fuzziness on any description of nature? Perhaps. But Feynman parted company with many of his colleagues. They looked to quantum uncertainty for an explanation of the many kinds