This started with the most innocent question in the world. I was supposed to be writing C code for my ESP32, a simple IoT project that should have taken maybe an hour to finish. But I stared at an if-else statement I had written thousands of times before, and suddenly asked myself: how does this actually work at the lowest level? Not how it works inside a programming language. But literally, physically, inside the machine, how does it happen? That one question cost me the entire night.
The first drop was actually reasonable. When logic scales up to millions of instructions, computers cannot read them one by one, so everything gets translated into matrices. Matrices act as operators, multiplying massive amounts of data simultaneously. That made sense. I thought I was just learning some computer architecture. But then I kept pulling the thread: to run these matrix operations you need physical hardware, and that hardware is built from transistors, which are basically tiny gates that control whether electrons flow or get blocked. One state is 1, the other is 0. Millions of these gates working together produce every calculation your machine has ever done. Still reasonable. Still within what felt like normal territory.
Then transistors got small. Modern chips are built at 3 nanometers, and at that scale electrons stop behaving like physical particles and start behaving like probability clouds. This is where Schrodinger walks in with his wave equation, describing electrons not as objects at a specific location but as smeared-out distributions of likelihood. And because they are smeared, a portion of that cloud can leak straight through the transistor wall without actually crossing it. That is quantum tunneling, and it is a real engineering problem that chip designers fight with right now. I did not expect my ESP32 project to lead me to actively used quantum effects, but here we were.
What genuinely blew my mind was finding out that around the same time Schrodinger was describing electrons as waves using calculus, Heisenberg was describing the exact same electrons as jumping discretely between states using matrices. Two completely different mathematical languages, two completely different mental pictures, both perfectly correct. Dirac later proved they are mathematically identical, just written differently. And the matrix formulation is what gives you the uncertainty principle directly: position and momentum are matrices, and matrix multiplication is not commutative, meaning the order you multiply them changes the result, and that non-commutativity is literally where the uncertainty comes from. It is not a limitation of measurement tools. It is baked into the algebra of reality itself.
From electrons I went deeper into the atom, into quarks, and things got genuinely strange. Quarks inside a proton are never in a fixed state. They continuously exchange gluons, swapping what physicists call color charge, and the vacuum around them is not empty but seething with virtual quark-antiquark pairs constantly popping in and out of existence. The proton is not a neat little cluster of three stable particles. It is a barely contained storm. And to keep that storm coherent, the quarks inside are entangled, meaning if one changes, the others respond instantly regardless of any barrier. Einstein hated this and called it spooky action at a distance. But in 2013 Maldacena and Susskind proposed something that reframed the whole thing: entanglement and wormholes might be the same phenomenon described in two different languages, the same way Schrodinger and Heisenberg were. Two particles being entangled might literally mean they are connected by a microscopic Einstein-Rosen bridge through spacetime.
By this point I was nowhere near my IoT project. But I kept going because the next layer was Planck time, roughly 5.39 times 10 to the negative 44 seconds, which is the smallest meaningful unit of time we know of. Go smaller than that and the math breaks, spacetime itself stops being a coherent concept. And sitting right next to that is the Measurement Problem: we have Schrodinger’s calculus and Heisenberg’s matrices, both of which predict quantum probabilities with extraordinary precision, and both of which completely fail to explain why those probabilities collapse to a single definite outcome the moment we measure anything. The equations tell you the odds. They say nothing about why one outcome actually happens. After a hundred years we still do not have a satisfying answer to that.
And then I ended up at black holes, which is where things get philosophically unhinged in a way I genuinely did not see coming. At a singularity, both general relativity and quantum mechanics produce infinities. The math breaks in both frameworks simultaneously. Which means the center of a black hole is effectively a bug in our best description of reality, a place where every equation we have either explodes or gives nonsense. There is a version of me that thought: if you could survive long enough to observe what actually happens there, you might see something that resolves everything, the moment right after the Big Bang when all four forces were still unified, the source code before it compiled into the universe we live in. And if at that level P turns out to equal NP, meaning every hard computational problem has a shortcut, then every layer of complexity sitting above it, from quarks to transistors to if-else statements, would suddenly look very different.
What I came away with was not answers, because at the deepest layers there simply are no satisfying answers yet. That is where Feynman’s words hit directly. In The Character of Physical Law (1965), he said:
“I think I can safely say that nobody understands quantum mechanics.”
And I sat with that sentence for a while. Not because it was discouraging, but because there is something honest and quietly relieving about it. Someone who spent his entire life inside quantum physics eventually raised his hands not out of ignorance but out of depth. We have built an entire digital civilization on top of something we use but do not fully understand. And the fact that I could trace that all the way from a single if-else in a microcontroller project to the edges of what mathematics can describe, well. Anyway. The ESP32 is still there. I’ll get to it.
Probably.