Can Evolution Explain Physics?

Other than the existence of evil and suffering, the most common objection to belief in God is that science has shown he doesn’t exist. Usually the claim is that, since we don’t need God to explain a particular physical phenomenon (e.g., the existence of the solar system or life or the human eye), then we don’t need God at all. 

And I think we should take this objection seriously. So let’s.

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I’ll focus on the claim that naturalistic or unguided evolution has explained the existence of humans. As Justin Taylor points out, it’s not at all obvious that God isn’t needed to explain important aspects of science. At least we’re far from actually explaining these phenomena using only the resources of naturalism.

I’d like to add an item to the list. This addition reveals a tension between evolution and our most fundamental theory of the universe: physics. Physics studies the building blocks of the universe, the cosmic LEGOs out of which everything else is built. These “LEGOs” include quarks, electrons, neutrinos, fields, energy, space, and time. And the precision to which physicists can predict the behavior of these objects borders on unbelievable. Physics is eminently impressive.

So the question is this: Can evolution—that is, evolution unguided by any intelligence either directly or indirectly—account for beings with the talent to discover the fundamental furniture of the universe? Can evolution explain physics?

But Is This Really a Problem?

It seems, however, that evolution has a ready response for our ability to discover truths about the world. I mean, imagine if prehistoric humans couldn’t accurately detect when a tiger or steep precipice was nearby. Any organism that couldn’t is no longer with us. Problem solved. 

Can evolution—that is, evolution unguided by any intelligence either directly or indirectly—account for beings with the talent to discover the fundamental furniture of the universe?

This may indeed be a reasonable response for our normal ability to navigate the world (though see Alvin Plantinga’s famous “evolutionary argument against naturalism”). But physics poses a special problem for evolution. In particular, the kinds of situations in which physicists make astounding discoveries are often very different from those that would’ve been encountered by our ancestors while they evolved on, say, the African savanna.

Differences

Let’s consider two of these differences: (1) the kinds of objects physicists have discovered and (2) the kinds of methods they’ve used to discover them. 

1. The Objects Themselves

The actual things physicists discover often lie far beyond the reach of sense perception. Electrons, quarks, and strings are forever beyond our ability to observe—even in theory. That is, given our most up-to-date knowledge about physics and physiology, no level of technology could in principle enable us to observe them. And if it turned out we’re wrong about this, then either our current physics is wildly wrong, or our current understanding of human physiology is similarly misguided. Or both. And yet it’s these current theories we’re trying to explain; these are the scientific theories that allegedly write God out of the equation.

You can’t have it both ways.

There’s another strange thing about the fundamental entities that physicists study: human intuition is totally unprepared for the way these “objects” behave. Electrons, for example, don’t act like the objects we encounter with our senses. For one, they can behave as particles or as waves, but they’re neither. Whenever we try to visualize what they’re actually doing, we inevitably get things wrong. Making inferences based on analogies between subatomic particles and, say, tiny ball-bearings can be misleading.

So, then, is there a naturalistic evolutionary story for our ability to discover such strange entities? Not currently; nor in the foreseeable future. There’s little reason to think the primary mechanisms of evolution—random genetic mutation and natural selection—would’ve resulted in organisms with abilities far beyond what they need for survival. There’s no clear source of environmental or social pressure that would’ve pushed organisms this far down the evolutionary path.

2. Methods We Used to Discover Them

In addition to the bizarre nature of the objects themselves, the methods by which some of them were discovered adds difficulties for an evolutionary story. One method is particularly relevant: the way physicists use mathematics to make discoveries.

Here’s one way to put the difficulty: Eventually, the existence of subatomic particles (to take one example) must be verified by experiments. But why invent experiments that—though they don’t detect the objects themselves—detect the posited effects of such theoretical objects? Much of the time we go looking for these effects. But how would we even know to go looking for them—much less where?

This is where mathematics comes in; it sometimes tells us these objects exist. A new equation might contain an unexpected variable that only makes sense if it represents some new type of entity. And lo, when experimentalists go looking for the object, they find it (or, again, its effects, which actually introduces new difficulties for an evolutionary explanation). The math acts as a seeing-eye dog, helping us detect things we will forever be blind to.

Is there a naturalistic evolutionary story for our ability to discover such strange entities? Not currently; nor in the foreseeable future.

But it’s even weirder than this. For one thing, the math is often so complex, obscure, and even counterintuitive that it’s surprising physicists are able to do it at all. Indeed, its excruciating complexity often postpones discoveries because the mathematics takes years for the physicists to learn. And frequently the math was invented by mathematicians years or decades before there was any idea of applying it to the physical world. Sometimes, it was developed merely for its beauty and interesting intellectual features.

And beyond the sheer difficulty, physicists often use the mathematical concepts to arrive at the physical equations themselves in unexpected ways. Many times they rely on intuition, gut feeling, and artistic creativity. That is, math and logic alone don’t lead to the mathematical formulae; a combination of insight, aesthetic sensibilities, ingenuity, analogy, and guesswork is also involved. All of this seems remarkably subjective. Yet it works.

Front Lines of Physics

In fact, this is a pressing issue in contemporary physics, one that touches on the nature of scientific inquiry itself. In 2018, the German physicist Sabine Hossenfelder published Lost in Math: How Beauty Leads Physics Astray, a book that ignited a firestorm of debate about the use of mathematics in physics. Hossenfelder points out that physics has been in a cul-de-sac for decades, particularly in its attempts to develop a quantum theory of gravity (of which string theory is the most popular candidate). Her diagnosis for this unprecedented stagnation is physicists’ reliance on aesthetic mathematical criteria for choosing theories. Mathematical beauty, she says, is not a reliable guide to truth.

Though some of her fellow physicists share this concern, others have pushed back. In his recent book, The Universe Speaks in Numbers: How Modern Math Reveals Nature’s Deepest Secrets, Graham Farmelo argues contemporary physics is actually benefiting from new and very difficult mathematics.

These are fun and interesting times in physics.

In any case—and this is the salient point for us—you can see why a naturalist like Hossenfelder would be suspicious of using mathematical beauty as a guide for progress in physics. Evolution lacks a plausible explanation for how a primate’s aesthetic sense might be a reliable indicator of a realm seemingly so disconnected from evolutionary factors. I’d be suspicious, too.

Evolution lacks a plausible explanation for how a primate’s aesthetic sense might be a reliable indicator of a realm so seemingly disconnected from evolutionary factors.

But I think it’s clear that beauty is, often enough, a reliable indicator of truth in physics. And this makes the universe look awfully user-friendly—awfully, well, designed.

Main Idea

Back to our question, then.

What are the odds that unguided evolution would’ve resulted in primates with the ability to do physics? These odds seem pretty slim to me—at least given what we currently know about science. Sure, if we don’t take current science seriously, we can imagine just about anything. But again, given current science, there isn’t a naturalistic evolutionary story of physics. It appears, in fact, that evolution is at odds with our deepest understanding of the universe.