Tuesday, July 31, 2018

Thinking about science upon entering the field. IV. Finale

Here is the fourth and final of a four-part series of posts by Tristan Cofer, a graduate student in chemical ecology here at Penn State.  He has been thinking about the profession he is being trained for, and the broader setting in which it is taking place, and into which he will have a place:

For my final entry in this series, I would like to revisit some ideas from my earlier posts, as they pertain to a book that I recently finished, called ‘What is Real?’ (Basic Books, 2018) by Adam Becker. The book recounts quantum theory’s formative years during the early twentieth century, focusing as much on the personalities that were involved in the theory’s development as on the science itself.

Becker devotes much of the book to the 1927 Solvay Conference, which gathered twenty-nine of the world’s leading physicists to discuss the newly formulated theory. Attendees at the conference were divided into two ideologically distinct groups. In the majority, were Werner Heisenberg, Max Born, and others who had adopted Danish physicist Niels Bohr’s ‘Copenhagen interpretation’.

Influenced by Heisenberg’s ‘uncertainty principle’, Bohr claimed that subatomic entities had ‘complementary’ properties that could never be measured at the same time. Electrons, for example, behaved like ‘particles’ or ‘waves’ depending on the experiment. To Bohr, this implied that electrons, photons, and other subatomic entities only had probabilities until they were measured. ‘Reality’ simply did not exist in the quantum world. It was therefore pointless to talk about what was happening on the quantum level, since quantum theory could not describe the way the world ‘is’.

On the other side of the aisle were Louis de Broglie, Erwin Schrödinger, and Albert Einstein who were adamant that physical systems were ‘real’ whether we acknowledged them or not. Led by Einstein, this group argued that although considerable advances had been made in developing quantum theory, it was hardly complete. Rather than do away with reality at the quantum level, Einstein et al. suggested that hidden processes, such as de Broglie’s ‘pilot waves’, could explain apparent contradictions such as wave–particle duality.

In the end, Bohr’s instrumentalist view won the day over Einstein’s realist one. Quantum mechanics was a closed theory that was no longer susceptible to change. Einstein and his supporters were largely ignored, and Einstein himself was painted as an out-of-touch curmudgeon who simply would not accept the new theory. At least that is how the story has been told over the past several decades. Becker, however, gives a slightly different account. He argues that the Copenhagen interpretation’s popularity had less to do with its epistemological value than with the cult of personality surrounding its architect, Niels Bohr.

Bohr was a ‘physicists’ physicist’ and the preeminent scientist of his time. In contrast to Einstein (who described himself as a ‘one-horse cart’), Bohr collaborated with other physicists throughout his career and mentored many others at his institute in Copenhagen, where he enjoyed considerable financial support from the Danish government. According to Becker, Bohr’s social influence, together with the convoluted and sometimes confusing way that he expressed himself, led many to revere him as a near mythical figure. Indeed, in one particularly telling passage, Becker quotes Bohr’s former student John Archibald Wheeler, who compared Bohr to ‘Confucius and Buddha, Jesus and Pericles, Erasmus and Lincoln’.

‘What is Real?’ serves as an important cautionary tale. While we want to believe that science advances only through its devotion to empirical fact, many ‘facts’ are decided upon not by what they say, but by who says them. We each belong to a ‘thought collective’ with fixed ideas that prevent us from seeing things objectively. Competing ideologies are quickly swept under the rug and forgotten. Indeed, in my experience, I have found that students are rarely exposed to the histories and philosophies that have shaped their respective disciplines. Do we all have our own ‘Copenhagen interpretation’, firmly enshrined in a scaffolding of tradition and convenience? I suspect that we do. To borrow a line from Daniel C. Dennett’s, ‘Darwin’s Dangerous Idea’: ‘There is no such thing as philosophy-free science; there is only science whose philosophical baggage is taken on board without examination’.

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