Science

I have written about one of Max Tegmark’s ideas already - the Mathematical Universe Hypothesis - and in doing so I admitted he sits at the top of my favourite physicists list. That post was about a single claim. This one is about the man, and about the thing I find more interesting than any individual theory of his: the through-line. Tegmark has spent a career moving steadily inward, from measurable cosmology toward the deepest possible questions about what reality is, and the move never feels like a physicist losing the plot and drifting into metaphysics. It feels like someone following the maths until it runs out of floor. ...

In Why Is There Something Rather Than Nothing? I admitted to an instinct I have never quite been able to shake: that the laws of physics are discovered rather than invented, and that mathematics might be genuinely fundamental - not a human language we lay over reality, but part of the bedrock. I said that if we ever reach base reality, maths is the thing most likely to get us there. I left it as a feeling. This post is me taking that feeling and seeing how far a serious physicist has been willing to push it. ...

“Are we living in a simulation?” is one of those questions that sounds like late-night dorm-room talk and then turns out to have a serious literature behind it. The honest short answer to “how likely” is that nobody knows, and that the question may not even have a clean numerical answer. But that is not a reason to wave it away. The reasons we cannot confidently put a number on it are themselves interesting, and they tell us something real about the limits of probability, the nature of consciousness, and what counts as science. ...

AlphaFold’s release in 2021 was the AI-for-science moment that broke through to the general public. A computational solution to a 50-year-old problem in biology - predicting protein structure from sequence - that produced a tool used by hundreds of thousands of researchers. The narrative around AI-for-science crystallised: deep learning would produce a series of similar breakthroughs across scientific domains. The 2026 reality is more interesting and less clean. AlphaFold-class breakthroughs have been rarer than the early narrative suggested. But AI has spread across scientific practice in subtler ways that, in aggregate, have done more to change how science is actually done than the few headline breakthroughs. ...

There are not many films where the visual effects pipeline produces a peer-reviewed physics paper. Christopher Nolan’s Interstellar is one of them. The visualisation of the supermassive black hole Gargantua was rigorous enough that it ended up in Classical and Quantum Gravity, co-authored by the visual effects team and Nobel laureate Kip Thorne. That single fact captures what makes the film unusual. It is, on the surface, a story about love, time, and survival. Underneath, it is a serious attempt to take Einstein’s general relativity and put it on a 70mm IMAX screen with as little fudging as Hollywood would allow. ...

I have always had this strange gut feeling that the universe is, in some sense, new all throughout the day. Not new in the dramatic science-fiction sense, where everything resets and starts over, but new in the sense that reality seems to keep unfolding into fresh versions of itself depending on what happens next. A conversation goes one way instead of another. You decide to go out, or stay in. You send the message, or you leave it unsent. Tiny differences, and suddenly the entire shape of the day changes. ...

One of the strangest facts about reality is that there is any reality at all. Not just stars, galaxies, black holes, planets, oceans, or people. Not just matter and energy arranged in complicated ways. The deeper mystery is that there is something rather than nothing. It is such a simple question that it almost feels childish when you first ask it. But it is not childish at all. It may be the deepest question we can ask. ...

Computing Bletchley Park Bletchley Park - The historic site of World War II codebreaking and the birthplace of modern computing. Located in Milton Keynes, UK. The National Museum of Computing TNMOC - Located on the Bletchley Park estate, this museum houses the world’s largest collection of functional historic computers, including the rebuilt Colossus and the Harwell Dekatron (WITCH). Centre for Computing History Centre for Computing History - Based in Cambridge, this museum focuses on the personal computing revolution and features a massive collection of vintage consoles and computers. ...

What Are Very Large Numbers? Large numbers exist on a spectrum so extreme that human intuition breaks down. From the observable universe containing roughly 10^80 atoms, to numbers so impossibly vast that they dwarf the atoms themselves, these magnitudes challenge our ability to comprehend scale. But they’re not just abstract curiosities. Large numbers appear in computer science (combinatorics, compression), physics (entropy, quantum possibilities), and mathematics (set theory, ordinal numbers). Understanding them requires leaving behind our everyday sense of “big” and embracing the mathematical structures that define these hierarchies. ...

Max Tegmark Cosmologist and physicist known for his work on the mathematical universe hypothesis and multiverse theory. His research bridges the gap between quantum mechanics and cosmology, exploring the deepest questions about the nature of reality. The Case for Halting AI Development Max Tegmark joins Lex Fridman to discuss the urgent need to pause advanced AI development, exploring the existential risks of artificial intelligence and what safeguards humanity needs as we approach transformative technologies. ...