September 7, 2020


The Idea that a Scientific Theory can be 'Falsified' Is a MythIt's time we abandoned it (Mano Singham, September 7, 2020, Scientific American)

J.B.S. Haldane, one of the founders of modern evolutionary biology theory, was reportedly asked what it would take for him to lose faith in the theory of evolution and is said to have replied, "Fossil rabbits in the Precambrian." Since the so-called "Cambrian explosion" of 500 million years ago marks the earliest appearance in the fossil record of complex animals, finding mammal fossils that predate them would falsify the theory.

But would it really?

The Haldane story, though apocryphal, is one of many in the scientific folklore that suggest that falsification is the defining characteristic of science. As expressed by astrophysicist Mario Livio in his book Brilliant Blunders: "[E]ver since the seminal work of philosopher of science Karl Popper, for a scientific theory to be worthy of its name, it has to be falsifiable by experiments or observations. This requirement has become the foundation of the 'scientific method.'"

But the field known as science studies (comprising the history, philosophy and sociology of science) has shown that falsification cannot work even in principle. This is because an experimental result is not a simple fact obtained directly from nature. Identifying and dating Haldane's bone involves using many other theories from diverse fields, including physics, chemistry and geology. Similarly, a theoretical prediction is never the product of a single theory but also requires using many other theories. When a "theoretical" prediction disagrees with "experimental" data, what this tells us is that that there is a disagreement between two sets of theories, so we cannot say that any particular theory is falsified.

Fortunately, falsification--or any other philosophy of science--is not necessary for the actual practice of science. The physicist Paul Dirac was right when he said, "Philosophy will never lead to important discoveries. It is just a way of talking about discoveries which have already been made." Actual scientific history reveals that scientists break all the rules all the time, including falsification. As philosopher of science Thomas Kuhn noted, Newton's laws were retained despite the fact that they were contradicted for decades by the motions of the perihelion of Mercury and the perigee of the moon. It is the single-minded focus on finding what works that gives science its strength, not any philosophy. Albert Einstein said that scientists are not, and should not be, driven by any single perspective but should be willing to go wherever experiment dictates and adopt whatever works.

The course of every intellectual, if he pursues his journey long and unflinchingly enough, ends in the obvious, from which the non-intellectuals have never stirred.
    -Aldous Huxley, Point Counter Point

Posted by at September 7, 2020 12:00 AM