Deinonychus antirrhopus

Uncertainty and Science

Kevin Drum posts about Chris Mooney's new book, The Republicans War on Science. Overall it isn't a bad post...except when we get to the end.

As Chris put it last night, Republicans want to turn science into yet another of the he-said/she-said shouting matches that work so well for them in other areas, generating uncertainty where none exists and undermining one of the few sources of objective knowledge we have.

Let me say up front that I'm not a big fan of Bush's. I don't like his stance on embryonic stem cell research. I think Bush's position in regards to Intelligent Design is embarassing. And the HIV/Condom issue is another area that I find annoying. But the above sentence indicates somebody who doesn't understand science. Science does not report eternal truths. Ever.

Science gives us evidence for evaluating various hypotheses. However, there is rarely if ever going to be enough evidence where we can claim something is True^TM. For example, if a scientist is evaluating his data using Frequentist statistical methods he will often report the results as "we fail to reject/we reject the null hypothesis". The issue is even more stark with Bayesian statistics where the validity of competing hypotheses are put in terms of probabilities. In the latter case, you really don't want to assign any hypothesis a probability of 1.

So science does not remove uncertainty, it merely allows us to better understand the issue at hand and to reduce the level of uncertainty. There are plenty of instances where scientists have thought one way, only to find out that they were wrong and had to change the model, theory, etc. that they were working with due to new discoveries and advancements.