Friday, August 7, 2020

Science begins and ends with humility

Science requires humility. Any scientific investigation starts with acknowledging ignorance. Scientific progress requires a willingness to admit mistakes and accept evidence, even when it goes against cherished and esteemed beliefs, theories, and colleagues.

As a scientist, I am fascinated by the science of covid-19, from the genetic code of the virus to the mathematical modeling of epidemics. I find it amazing how much we do know. It is also amazing how much we do not know.

The SARS-CoV2 virus is one of many coronaviruses; a name derived from the crown-like appearance of a virus particle in an electron microscope. The points on the crown are called spike proteins; they are attached to a spherical surface composed of other proteins. The diameter of the virus particle is about one-tenth of a micron. If you lined up ten thousand particles next to each other in a straight line they would be the size of a pinhead. The complete details of the atomic composition and geometrical arrangement of these spike proteins have been determined. This sphere (virus capsid) encapsulates the genetic information that is encoded in a single strand of an RNA molecule. The spike proteins allow a virus particle to attach itself to and enter a human respiratory cell. Inside the cell the virus particle bursts releasing the RNA molecule that then moves to the ribosome of the cell which then makes many copies of the RNA molecule. The information in each of these molecules is then used to manufacture the proteins that compose a virus particle. The copies of the RNA and proteins then reassemble into thousands more virus particles that then leave the host cell and move onto more cells.

It is amazing we know so much. Furthermore, we know the exact details of this genetic information. The RNA molecule in the SARS-CoV2 virus particle consists of a unique sequence of 33,000 letters (G, U, T, or C). In the laboratory, scientists can make a molecule with exactly this sequence and use these molecules to make artificial copies of the virus particles. We know so much. It is amazing. Aren’t we clever!

The flu epidemic of 1918-1920 killed more people than World War I. Back then we did not even know that RNA existed, the structure of any protein molecule, what the genetic code was, the mechanism of infection, how to mathematically model the spread of epidemics or the relative merits of different strategies for managing epidemics. We now know so much more. Today, this knowledge is saving thousands of lives.

Yet, we know so little. Although we know all the amazing details above, we cannot predict the structure of the virus particles. Furthermore, we don’t know the design of effective and safe drugs and vaccines to treat covid-19. A vaccine has never been developed for a coronavirus. This does not mean that it is not possible or even that it won’t happen in the next year. We also don’t really know how to balance the medical benefits and the economic and social costs of lockdowns.

Modeling, understanding, and describing social, political, and economic phenomena is even more difficult than physical, chemical, and biological phenomena. Scott E. Page is a Professor of Political Science, Complex Systems, and Economics at the University of Michigan. He teaches an online course, ``Model thinking’’ that has been taken by more than a million people. In his recent book, The Model Thinker, Page makes the case for using multiple models to describe human behavior.

We conclude with a plea for humility and empathy. In constructing models of people, a modeler must be humble. Given the challenges of diversity, social influence, cognitive errors, purpose, and adaptation, our models will inevitably be wrong, which is why we take a many-model approach.

Parenthetically, I note that this many-model approach is similar to the method of multiple hypotheses advocated by John Platt and that I have blogged about previously.

In 1932, Albert Einstein responded to a letter from Queen Elizabeth of Belgium, who complimented him on his lucid explanation to her of various topics in theoretical physics. Einstein wrote: 

It gave me great pleasure to tell you about the mysteries with which physics confronts us. As a human being, one has been endowed with just enough intelligence to be able to see clearly how utterly inadequate that intelligence is when confronted with what exists. If such humility could be conveyed to everybody, the world of human activities would be more appealing.

Quoted in Helen Dukas and Banesh Hoffman, Albert Einstein, The Human Side: Glimpses from His Archives. Princeton, NJ: Princeton University Press, 1979, 48.


The text above is an extract from a draft chapter that I have contributed to a forthcoming book produced with my friends in the "holy" scribblers group.

More to follow.

1 comment:

  1. Nice post! In my limited personal experience in HEP and some AMO/CM, I find humility is hard to come by in physicists. My own guess is that decades of reductionism and success in working on (comparatively) simplistic and well defined problems has made it difficult for physicists to accept their own ignorance.

    ReplyDelete

A very effective Hamiltonian in nuclear physics

Atomic nuclei are complex quantum many-body systems. Effective theories have helped provide a better understanding of them. The best-known a...