The recent discovery of two rare birds in Maine and the March for Science on April 22 provide a way to think about the power of science as a way of knowing.

On Earth Day, tens of thousands of people gathered in Washington, D.C. to promote the strength of science in improving our world and in advancing our knowledge. Many satellite Marches for Science, including several in Maine, were held for supporters who could not make the trek to our nation’s capital.

Scientific thinking unfortunately has little traction in our government. Of the 541 members of the U.S. Congress, only six have a degree in science or math. We have never elected a scientist as President although Grant, Hoover, Eisenhower and Carter did have engineering degrees.

Yet, the scientific approach has much to offer. First, science is evidence-based. As scientists, we must always be open to alternative explanations as we continue to learn. In other words, science is provisional. We must go where the evidence takes us.

Second, the scientific method embodies the notion of skepticism. We always need to question our interpretations. Although the distinction may seem subtle, scientists seek to disprove hypotheses, not confirm or “prove” them.

To explain a pattern, a scientist will come up with one or more hypotheses that can explain the pattern. Then, she will design an experiment to try to knock that explanation down. If her experiment is consistent with her hypotheses, she can design a different experiment to further test it. Colleagues may repeat her experiment. If the hypothesis stands up to these tests, we treat it as provisionally true. If the experiments fail to support the hypothesis, we reject it and move on to test other possible explanations.  Scientists try to disprove.

The beauty of this approach is that it removes one’s ego from the process. We all have great ideas. If we try to prove them, we run the risk of cherry-picking information to find information that is supportive and ignore, perhaps subconsciously, information that would disprove one’s great idea.

Psychologists call this effect confirmation bias. We selectively accept observations that conform to our expectation and blithely ignore observations that don’t fit.

Professor Richard Dawkins relates an anecdote of attending a seminar by a distinguished, older scientist. At the conclusion of the talk, a young student asked a perceptive question that essentially caused the speaker’s lifetime of research to crumble. Rather than becoming angry, the scientist went over and shook the student’s hand for his role in moving science further by disproving his hypothesis.

If you ever hear someone say that I proved my hypothesis, you know they do not understand the scientific method.

Let’s go back 2400 years to Greece. Aristotle wrote about many Greek birds. He noted that the five swallows there (including the familiar Barn Swallow) disappeared in the winter. He knew of no reports of occurrences of these birds elsewhere during the winter. He proposed that these birds hibernate. That is a perfectly good hypothesis; it can be tested.

As it turns out, this hibernation hypothesis became part of natural history lore and was not disproven for 2300 years. Even the great ornithologist Elliot Coues in 1882 was agnostic on the issue. Of course, now we have the evidence that swallows migrate to tropical areas to pass the winter.

Extraordinary claims require extraordinary evidence. The recent finding of a Fieldfare (a robin relative) in Newcastle and a Vermilion Flycatcher in Bremen on Hog Island should rightly invite skepticism. Fieldfare had never been reported in Maine and we have an earlier sight record of Vermilion Flycatcher but no photos. Fortunately, observers provided photographs of both of these recent rarities.  They are confirmed records.

As birders, we should question other observers’ sighting and prepare to have our own sightings questioned. These doubts should not be taken as insults on our abilities but rather the proper performance of scientific, skeptical inquiry.

[First published on April 30, 2017]