Thursday, December 13, 2007

The refining fire

Every year or so we hear of an experiment or proposed observation that will test the veracity -- say -- of general relativity to one more decimal point.

Why bother testing a theory with such precision when everyone already believes it to be true? Astronomer Bradley Schaefer of Yale University says: "We push as hard as we can, hoping that something breaks."

One of the reasons we have confidence in scientific theories is because scientists keep pushing and pushing, looking for cracks.

Scientists generally work within the confines of a "paradigm," a commonly held set of assumptions about how the world works. The questions scientists pose, and the answers they get are shaped by the paradigm. This is what the philosopher Thomas Kuhn called "normal" science.

Within normal science, minor cracks in a theory are sometimes ignored. Eventually, however, difficulties within a paradigm can become unsustainable, and a revolution occurs. A new paradigm is established, and work goes on.

It was a shift of paradigms, for example, that took us from Newtonian physics to Einsteinian physics.

Many critics of science see normalization within a paradigm as self-serving. Alternate versions of the "truth" are delegitimized, says the critics, and established science becomes the only legitimate game in town. Young scientists are acculturated within a paradigm, and spend the rest of their careers tweaking established theories. Dissent is frowned upon. Meanwhile, the real problems of society are ignored in the pursuit of an extra decimal place.

Science may be the only legit knowledge-building game in town, as the critics say, but so far no one has proposed a better one. And, yes, science has often allied itself with militaristic and corporate interests, and made some egregious excursions on behalf of prejudice. Nevertheless, I think history will show that, in the long haul, science has advanced the cause of human well-being.

At the same time, scientists should concern themselves with how research within an established paradigm can best serve society. Adding a twentieth decimal place to a theory's verification begins to look a tad self-indulgent in the face of such manifest problems as AIDS in Africa or growing inequalities of rich and poor.