|
|||
Science is in that sense conservative: new ideas are guilty until proven innocent. But radical theories can completely overturn previous orthodoxy, sometimes in quite short periods of time. There were two attempts at this in the 1980's, and one succeeded while the other failed. It's interesting to compare and contrast them. In about 1980, a team lead by Luis and Walter Alvarez proposed that the mass extinction at the end of the Cretaceous was caused by a very large metorite or comet striking the earth. This was radical and even close to heretical by the standards of the day, since for the previous hundred years catastrophism was a dirty word in the earth sciences. The orthodoxy since Lyell had been that everything happened gradually. So initially there was massive disbelief and dismissal. But other geologists and paleontologists took the idea and ran with it, testing different aspects of it, and the more they looked, the more it explained. It is now generally accepted, and as a result they've started looking for meteor strikes to explain some of the other mass extinctions in the paleontological record (and have started finding evidence of them). On the other hand, we have the now notorious Cold Fusion. In 1989, two electrochemists named Pons and Fleishman claimed that they had proved that when palladium electrodes were placed in solutions of deuterium oxide and a current was run between them, that more energy was released than had been fed in, with the excess coming from fusion of the deuterium inside the crystalline structure of the palladium. Given the slow pace of work on plasma fusion and the apparent failure of the laser-implosion approach, and given that this could be done at a very low level and involved quite simple equipment, it was quite an exciting prospect. The international physics community exploded into action, with attempts in major universities all over the world to duplicate the process and enormous discussion of possible theories behind it. (I remember reading the traffic in sci.physics at the time. People were very excited about the idea.) And almost all of the attempts failed, and in general the ones which were reported to have succeeded were the ones run with the worst controls by the least experienced groups. The ultimate consensus was that it was an example of experimental error, though there remains a core group of true believers who continue to work on it. And they may yet be proved correct, but the burden of proof is on them, and so far they have not satisfied that. The case for Cold Fusion did not survive the the critical process, and was not adopted by science. The difference between the two was the criticism. The Alvarez theory was strong enough to survive even in the face of the best its critics could throw at it; whereas Cold Fusion collapsed when it was critically evaluated. Without the criticism, they might both have been rejected or they might both have been accepted, and in either case Science would have gone wrong. Scientists understand the importance of this process, and accept -- even eagerly seek out -- criticism for their theories. The strength of the Scientific Method is that it keeps the wheat but discards the chaff, because of the power of criticismi. And that is the pattern that all thought should follow; it is criticism which makes the difference between deception and truth. Which is why it is so disturbing that those subscribing to certain political beliefs (you know who you are) refuse to accept criticism itself as valid, and assault it as being wrong. Without criticism there is no way to differentiate the foolish from the valid. (discuss) No-one has accepted |
|||
