Eric De Giuli

Highlights of the @APSphysics meeting: - sharing my latest work and seeing how physicists are pushing the envelope in bio - seeing old friends and chatting about physics, kids, and life, and - meeting bright young students and postdocs who will be the stars of the next generation

@lenbinus which papers? I explained the origin of agency (via noise) here: arxiv.org/abs/2503.15670

three papers dropped today that together tell one story: agency is prefigured in quantum non-Markovian processes, noise is the engine of behavioral flexibility, and xenobots can form memories without neurons. the old equation — mind = brain — is dissolving in real time.

@martinmbauer To be fair to the OP, the mass axis spans 20 decades while the y-axis only 2.

At 10*L/s, a 25m whale would need to swim 250m/s, that’s 900 km/h… The real lesson here is that ‚close on a log scale‘ isn’t really as close as you think it is

tomorrow on emulsion rheology! Come and chat, I'll be around all week

I'm speaking in Denver on Tuesday about noise-control duality, and ..

@SuryaGanguli Imagine teaching this and not at least announcing Euler's formula to inspire the students. It boggles the mind.

My 10 year old son just had to count the number of faces, edges and vertices for a bunch of polyhedra for his math homework. I then asked him to count faces - edges + vertices for all of them. It blew his mind that he always got 2 🤣

Many of my contributions in physics are downstream of noticing that others are talking past each other: instead of two myopic views (theories) of a phenomenon, there is often a richer, higher dimensional perspective that unifies them. This is true both socially and physically.

It is unfortunate that the two types of model are often conflated, and that we do not discuss RG until graduate courses. Are there any undergraduate texts where RG is foregrounded?

The word “model” hides two different ideas. Some models simplify reality to isolate a mechanism. Others predict universal properties shared by many systems. The renormalization group revealed the second possibility, and explains why simple models can describe Nature at all.

Fun exercise for a sleepless night: favourite author by age: 0-13 Hergé -18 Dostoevsky -20 Nietzsche -25 Tolstoy -30 Bowles -31 Chandler -40 Sebald

@curiouswavefn For most physicists, philosophy is an indulgence of youth, and old age. And Oppie didn't make it to the latter.

Interestingly, Oppenheimer did not seem to engage meaningfully in any way with Sanskrit after the war. Here's what Freeman Dyson told me: "In my twenty years of contact with Oppenheimer, I never heard him speak about the Bhavagad Gita or about his studies of Sanskrit literature."

Underrated Ideas in Biology (#9) Biology hasn't really had a "renaissance" since the 1960s. We can't accurately simulate a cell. There are many unknown unknowns, and a huge number of experiments can't be replicated. So what do we do? Well, in the 20th century, physicists used hydrogen atoms to develop a quantum theory of matter. By using the same atom across experiments, they could compare results and build a stronger knowledge base. Biology needs its own hydrogen atom. Specifically, I think we need to understand an organism in sufficient detail such that we can accurately simulate it computationally. The dream should be to run experiments on computers that faithfully replicate results from the real-world. Markus Covert's group at Stanford has been working on this for decades and has made tons of progress. DARPA recently launched a $35M program toward computational microbe models. But there is still room for an even larger effort here. We could start with E. coli or M. genitalium. The latter is nice because it has the smallest genome of any free-living organism. In 2006, the J. Craig Venter Institute found that only 382 genes in M. genitalium are essential. A whole-cell model of its life cycle was published in 2012. But even now, dozens of genes in this tiny microbe have unknown functions. We don’t fully understand how its molecules interact to carry out behaviors. Now is a good time to build an Institute wholly devoted to understanding a single cell. Everyone in the Institute would use the same cell line, and sequence it regularly to ensure it hasn't mutated. One part of the Institute would map its transcriptome and proteome at high spatial and temporal resolutions, in different environments. Other groups will build predictive models or do basic research into molecular mechanisms or behaviors, working out all the moonlighting proteins, filling in the "known unknowns," and finding "unknown unknowns." An accurate cell simulation would *prove* what we know and don't know, and also help us separate truthful data from flawed data. It works as a "hydrogen atom" because we can use the simulation to make predictions and then validate them experimentally. The fact we haven't already done this is quite embarrassing, in my opinion. It means there isn't enough funding or organization for moonshot projects in biology. Lewis Thomas was writing about "solving" an organism back in the 1980s. Even in 1973, Francis Crick published a paper called "Project K: The Complete Solution of E. coli," brainstorming on these ideas. (He was apparently inspired by Sydney Brenner, who was thinking about this by 1967.) In 2002, Crick gave up on the idea and said his proposal was "hopelessly premature, being before many key technologies, rapid computation, and the web." But now those things have been sorted out. We have the compute and most of the other technologies; and if we need more, we can invent them. What are we waiting for? Biology needs its hydrogen atom.

@carl_feynman @robinhanson Human brains are ~ the same everywhere, too

If you want to built the tallest possible thing using your available building materials, the result will be awfully close to a pyramid. Example: the Eiffel Tower is a tapered pyramid. Tallest structure buildable out of iron in 1887. Also, lions are impressive everywhere, and geometry is the same everywhere.

“Recurring motifs, giant T-shapes, step pyramids, inverted pyramids, lions, and sacred geometry, appear at Ionis in their most concentrated form before repeating at distant sites worldwide” dailymail.co.uk/sciencetech/ar…

@mmjukic You want to go back to having 5 of your 10 children die before the age of 10? We already have a world project: Science. Understanding the human body is like making sense of alien technology millions of years more sophisticated than our own. No need to go to the stars, yet.

It's hard to even explain why the collapse of civilization as we know it would be a bad thing. What do we even lose if we go back to medieval or Bronze Age levels? Material comforts? But if material comforts are the goal, our system is already optimizing for those right now.

Assumptions about geopolitics and the economy are basically all wrong. We live in a unipolar world empire with a planned economy, industry outsourced to China due to inability to replenish human capital, which took over the world thanks to the late 1800s technological explosion.

Thus the trope of physicist arrogance misses the mark, because it is only the public side of confidence calibrated to understanding.

@curiouswavefn Not in my copy. Guess I'll have to find another

@EricDeGiuli The World As I See It.

Einstein on his development of general relativity. All the great ideas of science are simple, in retrospect.

The most important lesson of theoretical physics is humility. One learns how many ways there are to rationalize some facts, and how few of them are correct.

@PashaKamyshev This is clear at the qualitative level, but much less so quantitatively. One needs to honestly estimate the various expenditures to justify the thesis. Consider e.g. K-12 education. Majority of salaries involved are not going to oligarchs. Many other examples.

@paulg @KTmBoyle Results are named after the last person who discovered them

@KTmBoyle You get credit for ideas in some fields, like math and the sciences.

You don’t get credit for good ideas or being early to them. You get credit for execution. Most systems measure by actions, not words. Amazing how many people forget this.