Saturday, March 13, 2010

On disagreement in science

As part of my essay on how science works, I described the notion that science operates on two important principles.

1. At any given time, those who engage in scientific research on a particular topic will have developed a consensus that represents a core of agreement regarding that topic among the majority of researchers. This consensus isn't some immutable truth - it's simply the view of the majority at that time. Nor is this consensus typically voted upon and approved by some sanctioning body.

2. At any given time, there may be one or more (perhaps many more) of those engaged in that research who disagree with the consensus. They're seeking to modify that consensus, changing it to one consistent with their dissenting understanding. Such disagreements are a natural part of the scientific process, not some sort of unfortunate conflict that signals a problem for the science.

Scientific consensus is the basis for how science proceeds in a systematic search for understanding. We proceed from the consensus, we teach the consensus, and the consensus is our guide for how to proceed. Overthrowing that consensus (so-called "paradigm shifts") is properly seen as the result of requiring the advocate(s) of some proposed new vision to provide extraordinarily convincing evidence. This process is logically and necessarily a "conservative" one. If our scientific understanding can be swept aside on flimsy evidence at the whim of an individual or subgroup, then it wouldn't represent anything substantial at all. This conservative character of scientific consensus sometimes makes those who wish to change that consensus angry and they may resort to all sorts of tricks to get their opinions heard, including airing their views in the media rather than engaging in the discourse associated with refereed scientific journals. Scientists are human and many of us have large egos - some without much basis for that large ego, of course.

Consider three scientific topics out of many: Global Climate Change, Tornadogenesis, and Evolutionary Biology. In each topic, I'll discuss different aspects of the debate about the consensus.

1. Global Climate Change. The overwhelming majority of those engaging in global climate change research is represented by the reports of the Intergovernmental Panel on Climate Change (IPCC). This is a rare example of a consensus arrived at with a vote of the participants. No doubt that step is needed to make it clear to non-scientists that this is indeed a consensus.

The "deniers" within the group of those actually engaged in climate change research (a larger group than the IPCC representatives) represent a very small minority, and most of them accept most of the IPCC's conclusions, only arguing for what amount to minor changes. Most of the "deniers" come from outside of the climate change research community, and many are quite far from being scientists at all (e.g., "pundits" such as Rush Limbaugh, Bill O'Reilly, Glenn Beck, etc.). Some are scientists in other fields. My point here is not to go into all of this debate once again, but to indicate that most of the public debate is between those not actually engaged in climate change research with those who are so engaged in and publishing papers in that particular field. If one were going to characterize the intra-science debate on this topic, it would necessarily be very one-sided, with the overwhelming majority supporting the IPCC. A "fair and balanced" argument between a real global climate change research and some skeptic from outside the field is a meaningless argument. It's not "fair and balanced", like some journalistic notion of "equal time" for the two viewpoints. The two viewpoints are inherently unequal. One represents the science of global climate change and the other represents ... whatever.

The reason for all of the uproar is that if global climate change has a large anthropogenic component and if the climate change processes we believe are underway continue to accelerate as a result of what we humans are doing, then any remedial actions could have negative consequences for certain elements of our society who have a strong pecuniary interest in the status quo. It's to their financial and/or political advantage to portray the science of global climate change as either some vast conspiracy against our society or as a scientific topic that needs to be "settled" once and for all before we actually do anything - that might threaten their particular special interests. [As discussed in my essay, scientific issues generally are not settled once and for all, ever! To expect so is a major misunderstanding of the scientific process.]

2. Tornadogenesis. There exist several different "factions" within the community of scientists regarding the topic of tornadogenesis. There is, of course, a considerable foundation of consensus in which they all operate, but folks don't necessarily agree about the details of the processes by which tornadoes are formed. If we were to write a textbook that would include a discussion of tornadoes, would it be appropriate to include the arguments currently ongoing about tornadogenesis? For the most part, the issues that divide tornado researchers are esoteric and operating at a level that would require an understanding of the consensus to even begin to grasp those arguments. Hence, a textbook for those learning about tornadoes shouldn't necessarily include a "fair and balanced" presentation of all those various viewpoints! Rather, it should summarize the scientific consensus - the bedrock of the science at any given moment. The fact that that consensus changes from time to time is reflected in the need for new textbooks from time to time. No big deal here.

Note that tornadogenesis researchers are not engaging in a bitter, protracted public debate within the media - they're not appearing on talk shows and engaging in videotaped verbal clashes with outsiders who have some contrary opinion regarding how tornadoes form. Crackpots email me from time to time to share their wild ideas on tornadogenesis. Would a debate between me and such a crackpot represent a meaningful and informative piece of journalism on the evening news? Such a debate would be silly and meaningless in the extreme, of course.

Furthermore, the "Horatio Alger" story of outsiders coming into a branch of science (perhaps from some other science, or perhaps not) and contributing revolutionary and important new ideas is mostly a myth. It happens, but only very rarely. When it does happen, the evidence must meet the criterion of being extraordinarily convincing - as was the case for the notion of continental drift proposed by the meteorologist Alfred Wegener. His story is significant in part because such an enormous paradigm shift from an "outsider" is so rare! And the convincing evidence came well after his death.

As of this time, there are no large economic issues tied to our scientific understanding of tornadoes. No political or religious group is objecting to the use of the vorticity equation (and other tools of research) as a means of illuminating tornadogenesis. There's no "creationist" or "political" version of tornadogenesis demanding "equal time" in the scientific journals, TV, and textbooks. To have a version of "God created tornadoes" advanced as a scientific hypothesis comparable to current tornadogenesis ideas is so laughable as to not deserve a nanosecond's worth of attention. In fact, of course, no one is advancing such a silly idea ... yet. I offer this absence of public debate regarding tornadogenesis as something for the global climate change deniers and creationists to ponder.

3. Evolutionary biology. In this "debate" being waged in various places throughout our society (legislative bodies, school boards, town meetings, etc.), the science of evolutionary biology is being assailed almost totally by non-scientists, seeking to inject their religious views in our schools and elsewhere. The representation of the "creationist" viewpoint as science is completely without foundation, as I've explained elsewhere (and many others have done so, of course). The notion of this being a "fair and balanced" representation of science is so utterly without substance that it would laughable, were it not being taken seriously by religious right-wing politicians, school board members, and textbook publishers. The points of debate here are not the equivalent of those between adherents of the scientific consensus and those minority scientists seeking to modify that consensus. This debate is almost completely between science and non-science. Scientific consensus is virtually unanimously in support of evolutionary biology. Any opinion outside of that consensus has yet to offer any meaningful evidence to gainsay evolution. To represent the two viewpoints in a textbook as equal elements of a scientific debate is absolutely without any basis. A potential outcome from representing this as a scientific argument is to expand on the already expanding ignorance of science resulting from the failures of our K-12 education process.

Science is arguably the most preeminently rational kind of thought. Logic is an essential element of the process and there's no place for politics and religion in science. To see it being misrepresented is both infuriating and depressing. We as a nation seem to be descending away from enlightenment toward the demon-haunted world of mythology and irrationality. Our nation's "Founding Fathers" were overwhelmingly a product of the Enlightenment, who had hopes that the United States of America could become a haven for rational thought and democratic principles, free from an imposed state religion, where dissent would be cherished for its ability to keep the tyranny of the majority in check. We seem steadily to be moving away from that vision. The choice remains ours, for the time being, but if we continue down this path of irrationality and "our side is always right", who knows what choices we will come to have? See the theocratic governments of the Islamist Middle East for a preview of what may be in store for us.

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