Modern Physics and the Human Person (Arnold Sikkema, ASA 2022)

I was not able to attend the American Scientific Affiliation 2022 meeting in person, but I signed up for access to the talks on line. Here I will summarize a talk by Arnold Sikkema, titled “Modern Physics and the Human Person.”  Dr. Sikkema is a professor of physics and chair of the Department of Mathematical Sciences at Trinity Western University, near Vancouver.

His outline notes the three major themes of this talk:

Composition is more than physical

Coherence across the multiple aspects of composition

Indeterminism

He starts off with a passage from “The Voyage of the Dawn Treader”, one of a series of books by C. S. Lewis depicting happenings in a world called Narnia. In this passage a boy from earth tells someone that in his world, a star is a “huge ball of flaming gas.” The boy is informed that “Even in your world, my son, that is not what a star is but only what it is made of.”

This introduces the notion that listing the physical components of an object does not exhaustively convey what that object is. In the case of stars, for instance, in addition to being “huge balls of flaming [reacting and glowing] gas,” they are the centers of planetary systems, sources of all atoms beyond helium, sources of radiant energy for planets, parts of galaxies, navigation aids, and objects of beauty and wonder.

Humans as Relationally Defined

When it comes to humans, we can start by listing out our physical composition (protons, neutrons, electrons; atoms), our chemical composition (molecules), and/or our biological composition (cells, tissues, organs, systems). However, this physical composition does not provide a comprehensive portrayal of what makes up a human being.

We are who we are and what we are also by our relationships with other humans, by our experiences of the past, by our hopes and dreams for the future, and by the narratives that shape our values:

Thus, we need to bear in mind the many dimensions of our humanity, especially those qualities which transcend the physical:

Electrons as Relational Beings

Dr. Sikkema then draws on his physics background to provide an illustrative analogy for the importance of a relational understanding of matter. He notes that, while as a particle, an electron is characterized by certain more or less static properties (e.g., charge, rest mass, spin), in order to describe any particular electron it is necessary to note its  interactions with other particles. Thus, “Electrons, like people, are composed of their relationships.”

An accessible method which physicists have of describing interparticle interactions is by the use of Feynman diagrams. Dr. Sikkema presented a couple of representative Feynman diagrams to illustrate some of these interactions with electrons:

To thoroughly characterize an electron, all of its possible interactions are calculated and factored into a “sum over histories”:

He is not trying make a rigorous proof of anything. Rather, he is noting that relationality is a pervasive feature in the physical universe, and so it should not be surprising that humans, too, are defined in large part by their relationships, not just by their constituent quarks.

In this next slide, Dr. Sikkema presents some thoughts on the relation between mental and physical aspects of our thinking and acting. Of course, one can identify events at the physical and biochemical level (neurons firing, etc.) which go into our decisions. Nevertheless, he suggests that there is a coherent agent, “I”, who decides to raise a hand or not.

Indeterminism and Humans

The next section of the talk deals with indeterminism and its impact on humanity:

At the microscopic scale, events like exactly when a particular radium atom will undergo nuclear fission are indeterminate (although we know with great precision what the probability is that it will split in a given range of time). At the macroscopic level, some processes are so complex and nonlinear and chaotic that for all practical purposes they are unpredictable. For instance, we can forecast the weather several days in advance with great accuracy, but even with complete data and perfect models, it may not be not possible to forecast more than about fifteen days out.

He notes that weaving indeterminism into an account of human thinking and choice is tricky: a purely deterministic approach seems to quench meaningful free will, and yet if neuron firing is driven by purely random processes, that also seems to detract from the notion of responsible agency:

His talk wraps up with three summary points:

( 1 ) Ontology is relational: electrons, persons, everything; this resonates with the interpersonal nature of the Trinity.

( 2 ) Human actions are coherent across all aspects, instead of top-down or bottom-up causation; God’s creatures are integral and whole.

( 3 ) The indeterminism of modern physics coheres with the indeterminism needed to be a human person; that said, “mystery remains”.

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Some of my reactions:

I appreciated Dr. Sikkema’s intelligent and humane approach. I learned a bit of particle physics (I was motivated to go read more about Feynman diagrams on Wikipedia), and was edified by his wholistic treatment of human beings.

I wished that he had delved a little deeper into the mind/brain problem. It may be true that there is a coherent “I” who makes decisions, but I hunger to learn more about how this “I” can emerge from the three pounds of nerve tissue in our crania (given that as best we can tell, every thought event has some corresponding set of physical events). However, it may be unfair to demand that a theoretical physicist produce insights that neuroscience specialists still struggle with.

There is a line of argument against a reductionistic treatment of human thinking that goes something like this: if you are claiming that conscious human thoughts and utterances are nothing but an epiphenomenal crust on the fundamental driving reality of purely physical (random or deterministic) electro-bio-chemical events among a bunch of neurons, then I have no reason to accept your claim – since it is nothing but an epiphenomenal crust on the fundamental driving reality of purely physical (random or deterministic) electro-bio-chemical events among a bunch of neurons in your brain. Dr. Sikkema does not invoke this argument.

He did not claim to be offering rigorous proofs of his statements of how indeterminism impacts humans. He characterized his conclusions as “suggestions”. In his twenty-minute presentation to a largely non-specialist audience he simply tried to offer a point of view which draws on insights and analogies from the world of physics, and which is also consistent with a universe created and sustained by God. I think he accomplished what he set out to do.