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By Tom Watts
Science has taken a beating in the policy world lately. While discussing the recent measles outbreak, Rand Paul, who is a medical doctor and should know better, said that vaccinations can lead to “profound mental disorders” (which, needless to say, is false). The Senate has also struggled with whether climate change is real and, if so, whether it is human-induced (which, needless to say, it is). These problematic incidents involving elected officials highlight some fundamental misunderstandings about science that are common enough to be worth clearing up.
Consider Einstein. Most people know that Einstein was a genius, but fewer know exactly what he did. His early contribution with the most lasting significance was the development of special relativity. Physicists had for decades struggled with the concept of a light wave; in particular, if light was a wave, then what exactly was waving? For waves on a string, the string is waving. For sound waves, air (or whatever the sound wave is passing through) is waving. For light, most physicists postulated a medium that would wave as the light passed through and gave it a Latin name, the “lumniferous aether.” But a difficulty quickly arose: the best tests to find this medium could not detect it. Einstein solved the problem by jettisoning the lumniferous aether: he formulated a theory of light that did not require any such medium.
The story of Einstein is relevant to climate change because some climate change deniers claim that scientists fail to challenge mainstream orthodoxy because they fear ostracism. This claim is false, but it’s also so implausible that it could be rejected out of hand even without evidence of falsity. Einstein challenged the prevailing view of light (that it traveled via the waving of the lumniferous aether). He was acclaimed not for agreeing with everyone else but for showing that everyone else was wrong. The same applies today: if anyone could demonstrate that the science around climate change was wrong, they’d win a Nobel Prize for sure. No one would hold back for fear of ostracism.
But wait! If Einstein showed that the dominant explanation of light was wrong, doesn’t that mean that overwhelming scientific consensus — as there is for climate change, evolution, vaccine efficacy, and so on — isn’t trustworthy? Can’t scientists be wrong, as they were about the lumniferous aether?
Again, Einstein can help. When Einstein created his new theory of light, he needed to reformulate laws of motion developed by Isaac Newton over two hundred years earlier. But Newton’s laws were mostly right; the problem was that light moves very fast, and Newton’s laws gave wrong answers about motion at very high speeds (in the hundreds of millions of miles per hour). At lower speeds, special relativity gives almost exactly the same answers as Newtonian mechanics. The theory did even less to modify our understanding of light; the heart of nineteenth-century electrodynamics, Maxwell’s Equations, depended not at all on the lumniferous aether.
So yes, overwhelming scientific consensus can be wrong, but usually on the margins of a theory, not at its core. If scientists do someday reformulate the theory of evolution, for example, it probably will end up looking much like today’s theory, except in some cases at the theory’s periphery. Evolution and other areas of settled science can be treated as facts, and, as John Oliver has pointed out, you don’t need people’s opinions on a fact; you can make policy based on facts regardless of the public’s views.
Of course, sometimes the science isn’t settled. This is often true of economics, where theory enjoys a more distant relationship with empirical reality. For example, basic microeconomic theory predicts that a minimum wage increase should increase unemployment (just as moving any price control away from the equilibrium price should decrease the quantity transaction in the market). When economists went to the data to measure this effect, though, they couldn’t find it. As a result, the Congressional Budget Office estimates that increasing the federal minimum wage to $10.10 would result in job losses ranging from zero to a million jobs (p. 9). That is, the effect could be anywhere from nothing to huge; they just don’t know the answer.
Nonetheless, it’s important not to conflate the two kinds of questions. There are some things we don’t know, such as the effects of increasing the minimum wage. There are some things we do, such as the usefulness of vaccines or the causes of climate change. When policymakers act as though the latter types of questions are the former, as we’ve seen in the past few weeks, they’re being irresponsible. Settled science, where it exists, is a good starting point for discussions of policy, and elected officials — including Senators, such as Rand Paul — would do well to remember that.