evanb

I worked in Jülich just shy of 6 years and never heard this story! I don't know if people know it and are shy about it or don't know it. But I've taken the tour of the citadel (which also serves as the local history museum) and didn't catch it there either.

Gell-Mann's totalitarian principle: in quantum mechanics anything not forbidden is compulsory.

https://en.wikipedia.org/wiki/Totalitarian_principle

I thought all of this machine learning business was about minimizing the loss.

You can adjust the speed of light and hold the fine structure constant (and all other dimensionless parameters) fixed by adjusting some of the other dimensionful parameters.

But you could collect this data point by chance in a bigger or smaller detector.

What I was addressing was whether this detector is big enough for a reliable discovery. In that case what you really want to constrain is the rate, such-and-such events per kilogram of xenon per year (the per-kilogram-of-xenon can be traded for a per-liter rate given the density of the xenon).

No one knows if it’s big enough—-that depends on the properties of dark matter and its interaction with xenon.

Whether or not they've "seen" 3x more events is a little bit of a tricky question, because while they may have captured 3x the data exposure (see sibling comments) experiments often operate blinded to the data. They can develop their analysis scripts, play out various different scenarios via Monte Carlo simulation, and get their whole pipeline working without the bias of actually seeing how each change in algorithm alters the outcome for the real data.

Then, at some point, they freeze their pipeline, "open the box", run the analysis on the real data, and report what they find. But they can only "open the box" once per exposure, after that you can worry that human bias can creep in.

Maybe there are even dark scientists trying to explain the missing 15% of the universe! One such scientist, easily pegged as a kook, suggests a model with SU(3) x SU(2) x U(1) gauge symmetry, with one sector spontaneously broken by a scalar field, and three flavors of fermions to allow for enough CP violation and masses spanning 10 or 11 orders of magnitude.

The total cost of this experiment may be a lot less than you expect. I'd encourage you to make a guess as to what you think it could cost the US taxpayer and then check what the Department of Energy contributed [1].

The LZ collaboration is going to run their machine until at least 2030. They have almost no hope of making a meaningfully larger detector, no will you hear them suggest one. Their detector is already designed at such a scale that it contains a substantial fraction of all the needed xenon isotope available on Earth.

[1] https://news.wisc.edu/dark-matter-detection-receives-10-ton-...

Yeah but no matter how hard I look I never seem to be able to read anyone else's email. Maybe OpenAI's upcoming models can help me find those references.

They aren't, as clicking through on a sibling's link demonstrates. Moreover, Senegal is nowhere near Cape Town.

Both / they're related. More mass gravitates more.

Suppose you had an infinite universe that was filled with a cool gas of low uniform density. Then the gravitational field at any particular point would be 0, by Gauss' law.

But, if you wait a brief moment the gas will not stay uniform, because each atom of the gas will have some velocity. You'll observe fluctuations: places with small over-density and small under-density (compared to the average). The places with over-density will gravitate more than the average and places with under-density will gravitate less, and gravity will cause the gas to clump.

Wait a few billion years and some places will have amalgamated whole galaxies' worth of matter around them and other places will be empty.

No, sorry, the singular surface in a Schwarzschild spacetime is not the event horizon. Nothing particularly interesting (from the GR point of view) happens at the event horizon.

Yes it is?

This page, which predates the recent olo work, calls it psychedelic aquamarine. https://jila.colorado.edu/~ajsh/colour/primary.html

Also the whole of the Virgin Islands!

I’m RSS-subscribed to a few sections relevant to my research.

The gilded age’s wealthy were also the winners of winner-take-all technologies such as the railroad and oil.

Given the energy scales involved, it's more likely that the issue lies with the approximations DFT makes to quantum mechanics, rather than the approximations quantum mechanics makes to quantum field theory.

I'm a professor of physics; my research area is computational quantum field theory. I was beginning a new approach for a certain kind of model. I know the model has not been simulated before (a collaborator has just constructed it for the first time using in-field knowledge developed in the last year).

I've been steadily more impressed, but the real startling moment was earlier this week, I could show that in a particular operation I had a bug (some identity wasn't satisfied) but I couldn't understand why. In one try Claude Code grokked my code, explained the problem to me (there were some dimension-dependent minus signs that needed to be computed), and fixed it.

The description is at https://theodore.net/projects/AvianVisitors/

By the Standard Model of Physics Software you can edit Quarkdown in Atom to get Quarkup and change your Neutron Mail to Proton Mail, but it only works if you type with your left hand and create an Electron app and an anti-Neutrinos AI blogpost.

In case the author is reading this, if you're going to introduce the complex-valued harmonics you should be careful to put the complex conjugate in the inner product

    <f, g> = ∫ f(ω)^* g(ω) dω

which does match the corresponding linear-algebra inner product if the vectors are over the complex numbers

    p . q = Σ_i p^*_i q_i

which guarantees that p.p ≥ 0 even for complex p (and does not change the only-real case).

Hmm. As a physicist my intuition is that information-preserving transformations are unitary (unitary transformations are 1-to-1). If a compression algorithm is going to yield a bit string (the zip file, for example) shorter than the original it can't be 1-to-1. So it must yield the zip file and some other stuff to make up for the space saved by the compression.

You could package all your data into a zip using this language but you would also have a worthless stretch of memory seemingly filled with noise / things you’re not interested in.

I don't remember much about music theory but I know enough about symmetry to know that there's a mistake in the diagram at 9 o'clock.

Bug report: I tried 6.999999̅ and got false. So there's some nonstandard model of the reals being leveraged here.