Tuesday, July 25, 2006


"Science is facts; just as houses are made of stone, so is science made of facts; but a pile of stones is not a house, and a collection of facts is not necessarily science."
Jules Henri Poincaré (1854-1912) French mathematician.

Pity the scientific community. Either people are complaining that the scientists can't decide what they think, or that they are just restating the obvious or they are outright wrong about major findings. And speaking from experience, the pay in science isn't enough to make it all the fuss worth the while.

While all of these accusations have been true at some point (DISCLAIMER: not necessarily in the cases I linked to!!), casting doubt on science has been one of the major efforts of the Bush administration, for the obvious reason that most findings of science have not been to their liking. This has been successful in part because people misunderstand the nature of scientific inquiry and the validity of the conclusions from science.

The short version is that science is about testing hypotheses in a rigorous manner. As Poincare said, a collection of facts is not a scientific theory. Are the conclusions from science "true"? If the process is done correctly (which entails peer review and replication), they are as close to true as the laws of inference will allow. Are they sometimes wrong? Yes, but when a large group of scientists is operating under completely false premises, there are usually some warning bells in terms of contradictory evidence, or the necessity for incredibly complex theories to explain the phenomena in question (see,e.g., the Ptolemic theory of planetary orbits). So scientists must always be asking themselves: Does the theory explain the data sufficiently well? What data are not explained by the theory? What predictions can be generated and tested by this theory?

Unfortunately, due to the politics of science and research funding (both very real) these safeguards are sometimes overlooked, both to sustain a untenable theory or to cast doubt on an undesirable one. To bring this back to a specific instance, the consensus of climate scientists is that a) global warming is real, b) a major cause, perhaps the major cause, has been human activity, and c) it will change life on this planet severely and irrevocably. This theory fits the data well, explains most of the available data, and it does generate hypothesis, some benign and others quite disturbing if they prove true (sorry about that, polar bears!). To argue otherwise is to throw random facts like rocks against a stone house.

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