Would It Happen Again?

🔁 The Question

Imagine we could rewind the universe to the beginning and press play again, with all the same starting conditions. Would it unfold exactly the same way – same galaxies, same Earth, same me writing this sentence? Would life itself appear again? Or would it drift somewhere completely different? The answer hangs on one thing: is there any true randomness in reality, or only causes we haven't traced yet?

🤖 The Machine That Surprises Us

A friend of mine scans the neurons of tiny fish and can predict what the fish will do tens of seconds before it does it. Meanwhile, ask a language model the same question twice and it answers differently each time. So which one has the free, unpredictable spark?Neither. The model is actually more predictable than the fish. Underneath, it is a fixed function: same input, same internal seed, exact same answer every time. The variety you see is deliberately poured in – a pinch of randomness added on purpose so it doesn't sound robotic. We just don't bother to look at the seed. Surprise is about our access to the state, not about real randomness.

🎰 Three Kinds of Randomness

Three very different things get lumped together under one word.

• Pseudo-randomness – what computers and most encryption run on. Back when I studied computer science we wrote these generators ourselves, and it was drilled into us to always call them pseudo-random: a programming language is deterministic, so it can only ever fake randomness with a clever recipe. Know the starting number and you know every result in advance.
• Physical randomness – the kind actually sold to casinos and lotteries. It samples real-world noise instead of running a recipe. Less predictable in practice, but still maybe just hidden causes.
• Quantum randomness – the only serious candidate for randomness that is real, not just unmeasured. And even this one is not settled.

❓ Is Anything Truly Random?

Strangely, physics itself can't settle it. The math of the quantum world can be read two opposite ways, and no experiment we have can tell them apart.One reading says the dice are genuinely thrown – outcomes are undecided until they happen, and re-running the universe could land somewhere else. The other says nothing is random at all; everything unfolds exactly, and the appearance of chance is just us not knowing which branch we're standing in. Both fit every experiment we've ever done. So "would it happen again?" isn't a naive question – it sits on one of the deepest unsolved cracks in physics.

⚖️ Randomness Wouldn't Set Us Free Anyway

People often reach for randomness hoping it rescues free will – if the universe isn't fixed, maybe I really am choosing. But a coin flip in my neurons isn't me deciding; it's just noise deciding for me. Random is not the same as free. Whether reality is rigidly determined or partly a dice roll, neither one hands me the kind of authorship I imagine I have. That paradox is what I sit with in Embracing the Paradox: Free Will and Determinism.