I had a piece in Quanta Magazine recently, about a tricky paradox that's puzzling quantum gravity researchers and some early hints at its resolution. The paradox comes from trying to describe "closed universes", which are universes where it is impossible to reach the edge, even if you had infinite time to do it. This could be because the universe wraps around like a globe, or because the universe is expanding so fast no traveler could ever reach an edge.

Sometimes, the world is silly for honest, happy reasons. And sometimes, it's silly for reasons you never even considered. Scientific projects often have acronyms, some of which are...clever, let's say. Astronomers are famous for acronyms. Read this list, and you can find examples from 2D-FRUTTI and ABRACADABRA to WOMBAT and YORIC. Some of these aren't even "really" acronyms, using letters other than the beginning of each word, multiple letters from a word, or both.

Encouraged by successes in understanding black holes, theoretical physicists are applying what they’ve learned to whole universes. What they’re finding has them questioning fundamental assumptions abo...

When a word has both an everyday meaning and a technical meaning, it can cause no end of confusion. I've written about this before using one of the most common examples, the word "model", which means something quite different in the phrases "large language model", "animal model for Alzheimer's" and "model train". And I've written about running into this kind of confusion at the beginning of my PhD, …

Scientists have different goals when they communicate, leading to different styles, or registers, of communication. If you don't notice what register a scientist is using, you might think they're saying something they're not. And if you notice someone using the wrong register for a situation, they may not actually be a scientist. Sometimes, a scientist is trying to explain…

Happy Halloween! I've got a yearly tradition on this blog of talking about the spooky side of physics. This year, we'll think about what happens...when you turn off the lights. Over history, astronomy has given us larger and larger views of the universe. We started out thinking the planets, Sun, and Moon were human-like, just a short distance away. Measuring distances, we started to understand the size of the Earth, then the Sun, then realized how much farther still the stars were from us.

A physicist and a cartoonist join forces with an accessible guide to thinking about life in the cosmos

I don't usually do obituaries here, but sometimes I have something worth saying. Chen Ning Yang, a towering figure in particle physics, died last week. Picture from 1957, when he received his Nobel I never met him. By the time I started my PhD at Stony Brook, Yang was long-retired, and hadn't visited the Yang Institute for Theoretical Physics…

I ran into this Bluesky post, and while a lot of the argument resonated with me, I think the author is missing something important. Shannon Vallor is a philosopher of technology at the University of Edinburgh. She spoke recently at a meeting honoring the 75th anniversary of the Turing Test. The core of her argument, recapped in the Bluesky post, is that artificial general intelligence, or AGI, represents an outdated scientific concept, like phlogiston.

The 2025 Physics Nobel Prize was announced this week, awarded to John Clarke, Michel Devoret, and John Martinis for building an electrical circuit that exhibited quantum effects like tunneling and energy quantization on a macroscopic scale. Press coverage of this prize tends to focus on two aspects: the idea that these three "scaled up" quantum effects to medium-sized objects (the…

Occasionally, people try to give "even-handed" accounts of crackpot physics, like people who claim to have invented anti-gravity devices. These accounts don't go so far as to say that the crackpots are right, and will freely point out plausible doubts about the experiments. But at the end of the day, they'll conclude that we still don't really know the answer, and perhaps the next experiment will go differently.

What is AI doing to higher education? And what, if anything, should be done about it? Chad Orzel at Counting Atoms had a post on this recently, tying the question to a broader point. There is a fundamental tension in universities, between actual teaching and learning and credentials. A student who just wants the piece of paper at the end has no reason not to cheat if they can get away with it, so the easier it becomes to get away with cheating (say, by using AI), the less meaningful the credential gets.

Black holes have been in the news a couple times recently. On one end, there was the observation of an extremely large black hole in the early universe, when no black holes of the kind were expected to exist. My understanding is this is very much a "big if true" kind of claim, something that could have dramatic implications but may just be being misunderstood.

Academics tend to face a lot of impostor syndrome. Something about a job with no clear criteria for success, where you could always in principle do better and you mostly only see the cleaned-up, idealized version of others' work, is a recipe for driving people utterly insane with fear. The way most of us talk about that fear, it can seem like a cognitive bias, like a failure of epistemology.

It's no secret that the early twentieth century was a great time to make progress in fundamental physics. On one level, it was an era when huge swaths of our understanding of the world were being rewritten, with relativity and quantum mechanics just being explored. It was a time when a bright student could guide the emergence of whole new branches of scholarship…

A paper about scientific fraud has been making the rounds in social media lately. The authors gather evidence of large-scale networks of fraudsters across multiple fields, from teams of editors that fast-track fraudulent research to businesses that take over journals, sell spots for articles, and then move on to a new target when the journal is de-indexed. I'm not an expert in this kind of statistical sleuthing, but the work looks impressively thorough.

According to Einstein’s theory of gravity, black holes have only a small handful of distinguishing characteristics. Quantum theory implies they may have more. Now an experimental search finds that any...

Sometimes, when I write a post about AI, I've been sitting on an idea for a long time. I've talked to experts, I've tried to understand the math, I've honed my points and cleared away clutter. This is not one of those times. The ideas in this post almost certainly have something deeply wrong with them. But hopefully they're interesting food for thought.

How much can you trust general relativity? On the one hand, you can read through a lovely Wikipedia article full of tests, explaining just how far and how precisely scientists have pushed their knowledge of space and time. On the other hand, you can trust GPS satellites. As many of you may know, GPS wouldn't work if we didn't know about general relativity.

I had a chat about journalism recently, and I had a realization about just how weird science journalism, in particular, is. Journalists aren’t supposed to be cheerleaders. Journalism and PR have very different goals (which is why I keep those sides of my work separate). A journalist is supposed to be uncompromising, to write the truth even if it paints the source in a bad light.

Have you heard of "vibe physics"? The phrase "vibe coding" came first. People have been using large language models like ChatGPT to write computer code (and not the way I did last year). They chat with the model, describing what they want to do and asking the model to code it up. You can guess the arguments around this, from people who are convinced AI is already better than a human programmer to people sure the code will be riddled with errors and vulnerabilities.