Is there any validity to the science behind global warming? If you believe the International Panel on Climate Change (IPCC) there’s no doubt that the science behind global climate change is solid; if you listen to the political debate you’ll hear a lot of people call it junk science. The term junk science is also used a lot in court – some forensic techniques and a great many defense strategies have been found to be less than scientifically rigorous (there’s a great book – Forensic Science in the Court by Judge Donald Shelton – that discusses the use of junk science by both the prosecution and the defense). Of course junk science is only one of the epithets we hear – there’s also pseudoscience, voodoo science, and then some more imaginative terms.
In 1974 the Nobel laureate Richard Feynman gave the commencement address to the graduates at the California Institute of Technology – for his topic he coined the term “cargo cult science” and spoke about the possibility that a scientist can come to apparently scientific conclusions that are not scientifically useful. Feynman didn’t think that the scientists were incompetent or deceitful – rather, he felt that most cases of cargo cult science stemmed from scientists fooling themselves by not seeing the flaws in their experiments. The cargo cults that the title referred to arose in the South Pacific in the aftermath of the Second World War – natives would build runways, wooden “control towers,” and even wear simulated headsets in an attempt to lure back the planes and people who had so impressed them. To Feynman, cargo cult science occurs when we follow a complex set of procedures that produce a result that, unfortunately, lacks scientific validity.
Feynman was not the first Nobel laureate to tackle this topic – he was preceded by Irving Langmuir who coined the term “pathological science” in a 1953 lecture at the Knolls Research Laboratory. In his lecture Langmuir noted that pathological science displays a number of symptoms:
- “The maximum effect that is observed is produced by a causative agent of barely detectable intensity, and the magnitude of the effect is substantially independent of the intensity of the cause.
- The effect is of a magnitude that remains close to the limit of detectability; or, many measurements are necessary because of the very low statistical significance of the results.
- Claims of great accuracy.
- Fantastic theories contrary to experience.
- Criticisms are met by ad hoc excuses thought up on the spur of the moment.
- Ratio of supporters to critics rises up to somewhere near 50% and then falls gradually to oblivion.”
Langmuir also cited a number of examples of pathological science, most of which have passed into oblivion in spite of having been well-known at the time. But we can think of some modern-day equivalents – the cold fusion controversy of 1989 comes to mind fairly quickly as does the speculation that vaccines can cause autism (which was thoroughly debunked recently when the scientific papers supporting this supposition turned out to have been fraudulent).
There is one obvious difficulty here – many of today’s accepted scientific theories would have been considered pathological science at some time in the past. Consider quantum mechanics – what would Newton have made of a theory that claimed the universe operated largely by chance? To Newton quantum mechanics would certainly have been considered a “fantastic theory contrary to experience,” it makes claims of great accuracy, and the effects would have been close to the limits of detectability – in fact, Newton would have considered quantum mechanics to meet at least 4 of Langmuir’s criteria for pathological science. It is quite possible that, in Newton’s day, some of our most successful scientific theories – quantum mechanics, quantum chromodynamics, and relativity theory, to name a few – may well have been considered pathological if only because they run so contrary to the world that we can observe and because there were no instruments capable of making the measurements needed to confirm (or reject) the theories’ predictions.
So how can we really know whether today’s “junk science” will remain “junk” or if will someday be vindicated? The fact is that we don’t – but there are a few of Langmuir’s criteria that might still be relevant. For example, for all its inscrutability, quantum mechanics has steadily gained adherents as more experiments are performed – contrary to Langmuir’s final criterion. In addition, when objections were raised in the early says of the theory, the responses were far from ad hoc – they were fairly well-considered and they helped to advance the theory. In these areas, at least, the theory of quantum mechanics may well have stood up as a legitimate scientific theory.
It is also worth noting that a huge number of scientific theories have made predictions that could not be verified for years or decades, yet they were still felt to be sound science (as opposed to junk or pathological science). Physicists Bose and Einstein, for example, predicted the existence of the Bose-Einstein condensate 70 years before it was first created in the laboratory, yet it was accepted that at some point the technology would exist to create it. It could be that some aspects of pathological science (by whatever name we call it) fall under Supreme Court justice Potter Stewart’s famous comment about pornography – that even if it can’t be precisely defined, we know it when we see it.
Politics and commerce seem to be where the majority of junk science claims are made – on many issues it seems that each side tries to bolster its arguments with scientific “theory” while attacking the others’ science as being junk. The climate change controversy falls into this category – at least now that it has entered the realm of politics – with each side of the issue accusing the other of using junk science.
This particular posting will not go much further on this topic but it does set the stage for future postings. From time to time I plan to use these criteria to examine various topics that are claimed to be junk science or that appear to be – we’ll see how they stack up against Langmuir’s and Feynman’s criteria to try to decide if the science (or the claim) holds water.