Category Archives: Certainty

Sabine Hossenfelder – Lost in Math: How Beauty Leads Physics Astray

Sabine Hossenfelder – Lost in Math: How Beauty Leads Physics Astray

Hossenfelder brilliantly covers the intersection of philosophy, hard science, and social science. She has a lot of wisdom about certainty, error, doubt, and why quantitative analysis is important and useful, but also prone to abuse. Her thesis is that a scientist’s proper goal is to understand the natural world. In that pursuit, many scientists get a little too caught up in constructing elegant mathematical models. Models and equations are useful when they add to understanding, which they often do. In fact, they are often vital to it. But models are a means, not an end.

To Hossenfelder, it is disconcerting how often scientists describe their models and equations as elegant. The word is everywhere. It appears constantly in scientific papers and conferences, in the classroom, and in popular-level books, magazine articles, and documentaries. Scientists sometimes even judge their theories and experimental results to be true or false based on whether they are viewed as beautiful or elegant. Even Einstein fell into this trap with his famous “God does not play dice” remark to express his unease with the Heisenberg uncertainty principle.

This is a problem because the universe does not care if people think it is beautiful or not. f=ma is either true, or it isn’t. Ptolemy’s laws, or Keplers, or Newton’s, or Einstein’s, or the string theorists’ ideas, are each either true or false. The answers do not depend on whether someone thinks they are elegant. Rather than chasing elegant ghosts, a scientist’s goal should be to get as close to objective understanding as possible, given human limitations.

Hossenfelder is a deep enough thinker to realize that our aesthetic sense likely evolved in response to our universe; causality runs both ways. It is not a coincidence that our eyes are most sensitive to the very E-M frequencies the sun sends our way, or that our ears respond precisely to the most common sound frequencies around us. In addition to our sensory organs’ capabilities being determined by evolutionary processes, so too did the way we interpret those sensory inputs.

Aesthetically, people tend to find beauty and elegance in evolutionary success, and ugliness in threats or failures to reproductive success. it is not a coincidence that signs of beauty are almost universally signs of youth, health, and fertility. Most people consider symmetrical faces more beautiful because symmetry correlates with good health, and with good genes. We prefer cleanliness over filth because bacteria and disease are bad for survival and reproductive success. So it makes sense that scientists, as humans who evolved in just this way, both have the aesthetic sense that they do, and that they feel compelled to find it in physics and other sciences.

If a symmetrical face is elegant and beautiful, so is a scientific equation that exactly has a given symmetry, or exactly fits a certain exponent. e=mc2 is much more appealing than, say, e=mc2.1. Some laws, such as this exchange rate between matter and energy, do have this elegant precision. This is fortunate, otherwise humans might never have discovered them! Other phenomena that are just as true are less elegant, such as entropy, the probabilism of quantum mechanics, or the way friction coefficients, alloys, and engineering tolerances all defy perfect precision in practice.

Our search for elegance in scientific research is a longstanding natural impulse redirected in a new and foreign direction. Humans have been a species for perhaps 200,000 years, and proper scientists for just a few hundred years–just a thousandth or two of that time. Our 200,000 years is in turn perhaps a touch more than one three thousandth of the animal kingdom’s existence. Our evolved aesthetic sense is very, very old. As such, it will be some time before evolution is able to adapt to our new social environment and address Hossenfelder’s concerns. Until then, the least we should do is be aware of our elegance problem.

While reading the book, I kept thinking it had just the sort of message that my former economics professor Russ Roberts would enjoy. One of the hallmarks of his approach is a conscious avoidance of certainty, and keeping in mind the difference between good and bad uses of statistics (Russ is also a keen and humble philosophical thinker). As it turns out, Russ had an excellent conversation with Hossenfelder on his EconTalk podcast. It’s worth a listen, especially for those who don’t have time to read the whole book.

Though Hossenfelder’s home is in physics, in several points during the book she acknowledges how her thinking applies to the social sciences. She’s right. Economists in particular would do well to consider her arguments. Her arguments about the parallel uses and abuses of mathematical modeling has some intersection with Jerry Z. Muller’s recent book The Tyranny of Metrics, though Hossenfelder’s arguments are more nuanced and broader-ranging, and have a deeper philosophical foundation.

Lost in Math also reminded me of F.A. Hayek’s The Counter-Revolution in Science, which distinguishes between science and scientism. As Hayek defines the terms, science is the process of learning about the universe and the beings who live in it. Scientism is more about method-worship, valuing mathematical rigor and elegance as its own end. When taken too far, scientism can color results and potentially stunt entire research programs and lines of inquiry.

This has happened in economics. Crudely, science and scientism can be personified as Adam Smith vs. Paul Samuelson–though again, very crudely. Peter Boettke contrasts mainline vs. mainstream economics to make a similar point. Smithian mainline economists are interested in the human condition; mainstream Samuelsonians are a little too interested in technical proficiency and elegant modeling. They would do well to focus a little less on Homo economicus, and a little more on the admirable and real, though admittedly less elegant, Homo sapiens.

Richard Panek – The Trouble with Gravity: Solving the Mystery Beneath Our Feet

Richard Panek – The Trouble with Gravity: Solving the Mystery Beneath Our Feet

More philosophical than I expected. Panek gives an excellent history of gravity, from Aristotle on down through Philoponus, Galileo, Newton, and on down the line. Philoponus, an Egypt-born 6th century Byzantine philosopher, was someone I was unfamiliar with, and it was a treat learning about a new figure in the history of science. He figures prominently early in the story, and more or less came up with the modern understanding of inertia, which he called impetus.

Unusually for his time, Philoponus was not content to rely on Aristotle and Plato’s works as settled fact. He preferred some measure of empiricism. He did not go as far as Francis Bacon’s audaciously titled New Organon (intended to replace Aristotle’s Organon, which was all but an eternal sacred text), but Philoponus’ empiricism was still controversial.

While Panek ably explains the science of gravity at a popular level, he is clearly more interested in the philosophy surrounding it. In particular, if you ask a scientist not what gravity is, but why it exists, they have no choice but to tell you they do not know. That, more than anything, is what interests Panek, and what drove him to write this book.

A good scientist has no problem admitting they do not know something, of course. A lifetime of study and experiment tells even the most brilliant scientist nothing about why, only about the what. Maybe someday we’ll gain that level of knowledge. But after so many attempts from Aristotle to Philoponus through today’s sophisticated experiments, Panek is not optimistic.

Healthy Attitudes of Inquiry

From p. 6 of Vlad Tarko’s 2017 book Elinor Ostrom: An Intellectual Biography:

Good social scientists are like tourists who have yet to familiarize with the local rules or a little bit like children, asking funny questions about what everyone else just takes for granted.

This is a much healthier attitude of inquiry than the capital-C certainty many analysts have in their answers to social problems.

Sarah Bakewell – How to Live: Or A Life of Montaigne in One Question and Twenty Attempts at an Answer

Sarah Bakewell – How to Live: Or A Life of Montaigne in One Question and Twenty Attempts at an Answer

Despite the title, this delightful volume is no self-help book. It is mostly a biography of Montaigne, the 16th century Frenchman who invented the modern essay, which means “to try” or “to attempt”.

The very word captures Montaigne’s basic humility. He did not intend his essays to be definitive, or the last word on the subject. His writing style and his philosophy were thoughtful, gentle, playful, scattershot, introspective, and curious. Montaigne conspicuously lacked certainty and dogmatism, which occasionally got him in trouble. Above all else, he seemed to value peace and quiet, and seemed to view his time as Bordeaux’s mayor as a burden, not an honor. Readers who know me personally can understand why Montaigne has long been one of my favorite thinkers.

Bakewell expertly captures his spirit. Rather than a straight biography, she mimics Montaigne’s literary approach in the Essays. She tells the story of both Montaigne and his writings in bits and pieces, going on frequent tangents while staying mindful of larger themes, such as humility and taking joy in little things.

Forecasters in Proper Context

Whether it’s the local weatherman getting it wrong, or especially some economic shaman predicting the stock market’s next swing, forecasters have a record that doesn’t always outperform chance. This poor record has been known since at least Roman times, as Deirdre McCloskey notes on p. 265 of her 2000 book How to Be Human, Though an Economist:

The early Latin poet Ennius sneered at forecasters “who don’t know the path for themselves yet show the way for others.”

Or, as the philosopher Yogi Berra put it, “It’s tough to make predictions, especially about the future.”

Debunking Cognitive Biases

My former professor Bryan Caplan stars in a series of short videos about four cognitive biases that explain why voters systematically vote for bad policies. You can read about them in detail in his 2007 book Myth of the Rational Voter, or you can watch these videos:

Make-Work Bias

Pessimistic Bias

Anti-Market Bias

Anti-Foreign Bias

A Lesson in Humility

An important bit of wisdom from p. 25 of Rolf Dobelli’s The Art of Thinking Clearly:

There are about one million trained economists on the planet, and not one of them could accurately predict the timing of the 2008 financial crisis (with the exception of Nouriel Roubini and Nassim Taleb), let alone how the collapse would play out, from the real estate bubble bursting to credit swaps collapsing, right through to the full-blown economic crunch. Never has a group of experts failed so spectacularly. The story from the medical world is much the same: Up until 1900 it was discernibly wiser for patients to avoid doctor’s visits; too often the “treatment” only worsened the illness, due to poor hygiene and folk practices such as bloodletting.

The lesson to be learned is a familiar one: beware the rule of experts. No matter how clever you are, be a student of society. Don’t try to be its savior. That is well beyond any one person.