The term “quantum mechanics” is very much a misnomer. It should, perhaps, be called “quantum nonmechanics”.
These are the words of theoretical physicist, David Bohm, one of many who have attempted to make sense of the microscopic world. You see, quantum mechanics describes the smallest aspects of nature quite well, but it is so very different from our expectations of how things behave in the world of everyday experience.
Even more, it is filled with counterintuitive, fuzzy, and at times spooky surprises. Depending on who you are, that will either a) get you really excited, or b) make you very nonexcited. But bear with me – it’s a hard topic, both to explain and to understand. My hope over the course of a few weeks is that we will gain at least a rudimentary grasp of some of its more profound features.
Quantum mechanics does not cause as much heat in the church as topics like evolution, but I find investigation into the laws governing Creation to be most exhilarating at the quantum level. So let’s give it the old college try…
Atoms with Slit Personalities
Objects governed by quantum mechanics literally surround us, though we can’t see them. Most modern technology harnesses some form of quantum mechanics; without it, we probably don’t have transistors, which are in nearly every device in my office, kitchen, and pocket. That is to say, it works really well, despite some of its more mind-boggling features.
Many introductions to quantum mechanics begin with the famous two-slit experiment, which shows several fascinating things about the dual nature of the smallest particles. How you track particles, using an apparatus like in the two-slit experiment, seems to influence the behavior they display: either that of a wave or of a particle. And when you are not looking, quantum mechanics suggests they are simultaneously both particle and wave-like. You read that correctly. They are not one or the other, but both, the so-called wave-particle duality.
I’ll stop right here and just say that the two-slit experiment is much easier seen than explained. It’s one of those things where it’s better to “show, don’t tell”—which is why I highly recommend you stop reading right now and take nine minutes to watch this excellent explanatory video.
Seriously, right now. I’ll wait…
OK, welcome back. That was helpful, wasn’t it? And quite astonishing—almost as if the atoms have minds of their own, “behaving” one way at one time, and another way at another . . . depending on whether we observe them going through the slits. This is often called the measurement effect or the role of the observer.
There is a third feature, less obvious from the video, and that is the fact that probabilities govern the world of particles. Until you observe and make a measurement, the path of the particle or the outcome of your experiment has a range of possible paths or locations, and those mathematical equations of quantum mechanics give a range of probabilities for each possible results.
This is very unlike the objects of everyday experience, where the governing mathematical laws are deterministic. Think here of mass, velocity, angles, and forces like friction determining whether the eight ball really does go into the corner pocket. Location and path cannot be fully described in quantum mechanics. Instead, probabilities govern the system until the observer enters in.
Astonishing, isn’t it? Duality and observer effects and probabilities. It is a lot to explain in a few paragraphs so do click the links below. And if you don’t really get it, you’re not alone. As physicist Jim al-Khalili joked in the video, “If you can explain this using common sense and logic, do let me know, because there is a Nobel Prize for you.”
- Again, here’s that very helpful video description of the two-slit experiment.
- The quest to understand the two-slit experiment continues to this day.
- Many interpretations exist trying to make sense of the 2-slit experiment.
- The Born rule connects the math of quantum theory to the outcomes of experiments.
- A Catholic physicist brilliantly explains quantum theory and its relevance to faith.
Mind the Quantum Gaps
At this point of the newsletter, I usually encourage you to consider the science I just presented in your sermons or lessons, or in connection to Scripture and theology. But that is not what I am doing this week. Instead, I want to issue a warning about jumping to conclusions.
Quantum mechanics is so weird, so counterintuitive, and so poorly understood at the most fundamental level—dozens of interpretations exist trying to make sense of it—that it is risky to draw theological conclusions.
Does God play dice? Do duality, observer effects, and probabilities truly describe the world God created? Or do they point to a veil that hides the microscopic world from us?
Fascinating questions, but to stake a theological claim in any one particular answer could come back to bite us. It’s called the God of the gaps. If we align our faith with any particular interpretation of quantum mechanics, then what happens if physics eventually eliminates a gap—and with it, our preferred interpretation? We do ourselves no favors tying our theology to any details science may explain away at a later date.
Still, quantum physics begs us to ask: What kind of God would create a world like this? Is it the God who determines all things, or one open to possibilities at the most fundamental level? Is it a God revealed or hidden?
Such questions may keep you up at night. It’s hard to find answers while our understanding of quantum physics remains so unsettled. But I hope, like me, you will find such a God to be fascinating, perhaps elusive, and yet still worthy of praise, despite—or because of—these mysteries.
“Can you fathom the mysteries of God? Can you probe the limits of the Almighty? They are higher than the heavens above—what can you do? They are deeper than the depths below—what can you know?” (Job 11:7-8)