Reposted by Moritz SchauerSam Power @spmontecarlo.bsky.social · 03/10/2026Some months late: shapes in Spain 1212
Moritz Schauer @mschauer.bsky.social · 03/10/2026That's quite a bit of lovingly filling in the details of my prompt. 010
Moritz Schauer @mschauer.bsky.social · 03/10/2026But the spider web itself is implemented using an ad hoc solver of Hooke's law - the solver iteratively moves each free node in the direction of its net force. That is why adding a radius visibly shifts the hub and deforms the frame rather than simply drawing a new straight segment. 110
Moritz Schauer @mschauer.bsky.social · 03/10/2026There are some cinematics in there - the code that generates the impression of a thread moving in the wind is just a really nicely chose parametric curve... 100
Moritz Schauer @mschauer.bsky.social · 03/10/2026And for all us children that like to build correct spiderwebs in their living room, I thought I try Claude with manim to animate and narrate this. Amazing, honestly m.youtube.com/watch?v=qF87...m.youtube.comOrb-web spider builds web / Build a realistic spider webYouTube video by Moritz Schauer 120
Moritz Schauer @mschauer.bsky.social · 03/10/2026Sick child last week - but the scientifically correct spider net kept us entertained. 170
Moritz Schauer @mschauer.bsky.social · 24/09/2026I elaborate a bit about this "Extension theorem? Caratheodory? Let's first try to extend a premeasure to a single new set" here: mathoverflow.net/a/512016/593...mathoverflow.netDemystifying the Caratheodory approach to measurabilityNowadays, the usual way to extend a measure on an algebra of sets to a measure on a $\sigma$-algebra, the Caratheodory approach, is by using the outer measure $m^* $ and then taking the family of all 020
Moritz Schauer @mschauer.bsky.social · 24/09/2026#MathSky Trying to demystify Caratheodory's measure extension theorem: mschauer.github.io/share/friend...mschauer.github.io 163
Moritz Schauer @mschauer.bsky.social · 21/09/2026This is fun! 𝓕(m) ∨ 𝓕(n) = 𝓕(lcm(m,n)), 𝓕(m) ∩ 𝓕(n) = 𝓕(gcd(m,n)). 110
Moritz Schauer @mschauer.bsky.social · 21/09/2026The σ-algebra viewpoint also gives a nice form of the Chinese remainder theorem: for pairwise coprime n₁, …, nₖ it holds σ(x mod n₁, …, x mod nₖ) = σ(x mod n₁⋯nₖ). Knowing the residues separately is exactly the same information as knowing the residue modulo the product. 1102
Moritz Schauer @mschauer.bsky.social · 21/09/2026Here is Furstenberg's topological version: en.wikipedia.org/wiki/Fursten...en.wikipedia.orgFurstenberg's proof of the infinitude of primes - Wikipedia 141
Moritz Schauer @mschauer.bsky.social · 21/09/2026But each 𝓕ₚ is finite, and finitely many finite σ-algebras generate a finite σ-algebra. Hence 𝓕 cannot be generated by only finitely many 𝓕ₚ. Therefore P is infinite: There are infinitely many primes. ☐ 131
Moritz Schauer @mschauer.bsky.social · 21/09/2026Since every integer except −1 and 1 has a prime divisor, ℤ ∖ {−1,1} = ⋃ₚ pℤ, so {−1,1} ∈ 𝓕. Each 𝓕ₚ contains the translations of its elements, hence so does 𝓕. So {−1+k,1+k} ∈ 𝓕 for every k ∈ ℤ. These sets are all distinct, so 𝓕 is infinite... 130
Moritz Schauer @mschauer.bsky.social · 21/09/2026For example, 𝓕₂ = σ(2ℤ, 1 + 2ℤ) has four sets: ∅, ℤ, the even integers, and the odd integers. Now let P be the set of primes and combine all this information into 𝓕 = ⋁ₚ 𝓕ₚ (p ∈ P). 130
Moritz Schauer @mschauer.bsky.social · 21/09/2026Furstenberg gave a fascinating proof that extracts the infinitude of the primes from seemingly innocuous manipulations of clopen sets. Here is a retake: The σ-algebra 𝓕ₚ = σ(n ↦ n mod p) encodes exactly the information contained in knowing n mod p. That is natural, σ-algebras model information. 1102
Moritz Schauer @mschauer.bsky.social · 14/08/2026How many times does the Moon go around the Earth in a year? About 13 times relative to the stars. But Earth itself goes once around the Sun. So the roughly 12 lunar months in a year are really a 13 − 1 phenomenon — the same geometry as a circle rolling inside a larger circle. 010
Moritz Schauer @mschauer.bsky.social · 13/07/2026Modern search: “You came looking for X, but wouldn’t you rather spend some time on the more addictive Y?” 060
Moritz Schauer @mschauer.bsky.social · 10/07/2026We could try to build a very expensive high energy quantum computer ring under Paris 000
Moritz Schauer @mschauer.bsky.social · 03/07/2026Dank Kompositionalität lernt man das Einmaleins aber nicht mehr das Einmaleinmaleins 010
Moritz Schauer @mschauer.bsky.social · 01/07/2026For that price, we get all of mathematics with randomness added. A bit like adjoining complex numbers to the reals for the price of losing the natural order. It’s funny to think how such things commute: think of complex random variables versus complex probabilities. 040
Moritz Schauer @mschauer.bsky.social · 01/07/2026The redeeming feature is that this price is paid only once. 161
Moritz Schauer @mschauer.bsky.social · 01/07/2026Probability theory causes a certain mathematical inflation: random variables are functions, events are sets, and probabilities are countably additive set functions of total mass one defined on σ-algebras. 250
Moritz Schauer @mschauer.bsky.social · 01/07/2026Paper link: doi.org/10.1145/3808...doi.orgGradInf: Gradient Estimation as Probabilistic Inference | Proceedings of the ACM on Programming LanguagesGradient estimation—the task of computing the gradient of the expected value of a probabilistic program—has diverse applications in scientific computing, but is notoriously difficult because of issues such as high-dimensional integration, discrete random ... 041
Moritz Schauer @mschauer.bsky.social · 01/07/2026Gaurav Arya’s presentation at PLDI'26 on "Gradient Estimation as Probabilistic Inference" bringing sound, compositional and automatic gradient estimation for expectations in probabilistic programs. Great job, Gaurav!! www.youtube.com/watch?v=0aWz...youtube.com[PLDI 2026] Flatirons 3 - PLDI Research Papers (Jun 19th)YouTube video by ACM SIGPLAN 140
Moritz Schauer @mschauer.bsky.social · 09/06/2026No feeling like arguing for 40 minutes with a confident idiot, only to realize they were right for all the wrong reasons. [1.2em] 030
Moritz Schauer @mschauer.bsky.social · 06/06/2026Zorn's lemma: Transfinite induction as a service 040
Moritz Schauer @mschauer.bsky.social · 25/05/2026Probably there is no secret “scientific method” and emerges automatically from discussions running in circles 000
Moritz Schauer @mschauer.bsky.social · 03/05/2026AI is not allowed to make goblin-metaphors anymore but it will appreciate my hidden goblin poetry 020
Reposted by Moritz SchauerArXiv Paperboy (Stat.ME+Econ.EM) @paperposterbot.bsky.social · 30/04/2026arXiv📈🤖 The Difference Between "Replicable" and "Not replicable" is not Itself Scientifically Replicable By Devezer, Buzbas 062
Moritz Schauer @mschauer.bsky.social · 24/04/2026(Thinking about causal discovery more than estimating effects in a given causal model, there I don't know really) 020
Moritz Schauer @mschauer.bsky.social · 24/04/2026To me one very striking issue is the apparent lack of success stories... 110
Reposted by Moritz SchauerArXiv Paperboy (Stat.ME+Econ.EM) @paperposterbot.bsky.social · 24/04/2026arXiv📈🤖 Betting on Bets: Anytime-Valid Tests for Stochastic Dominance By Arnold, Choe, Scarsini et al 021
Moritz Schauer @mschauer.bsky.social · 23/04/2026Causal inference tells you that some features of DAGs are identifiable from the observations (the v structures!). So if you are lucky that alternative candidate DAGs differ in v-structures, the data tells them apart (e.g. by computing the model fit/evidence for corresponding Gaussian linear SEMs) 130
Reposted by Moritz SchauerWill Lowe @conjugateprior.org · 11/11/2025Yes, that's the contrast of interest The relevant observations are imo 1. MH is a causal inference problem first and a probability problem second, and 2. the association usually called collider bias is information you can make use of for decision rather than just being, as it normally is, a problem 141
Moritz Schauer @mschauer.bsky.social · 24/03/2026I have not getting filter coffee in a coffee place and not getting gyros in a Greek restaurant until acing the local speech patterns… Don’t people have priors?? PS: ”Chyros? really, Dutch friends, chyros?” 010
Moritz Schauer @mschauer.bsky.social · 11/03/2026Dust behaves as if someone put a minus sign in front of the Laplacian: dust ends up in the corners instead of spread out. 040
Moritz Schauer @mschauer.bsky.social · 28/02/2026Witnessing the birth of the marginal differential product theory about hiring your enemies 020
Moritz Schauer @mschauer.bsky.social · 24/02/2026I like that people genuine think in intervals. Maybe there is hope to explain the confidence interval 010
Reposted by Moritz SchauerDarren Dahly @statsepi.bsky.social · 23/02/2026This is basically my villain origin story. "How old are you?" (unique responses) 116110
Moritz Schauer @mschauer.bsky.social · 21/02/2026My slides are of course not a text book, but I link them here because they are opinionated that perhaps you can get away without GES or PC and get there by compute and a simpler hill climbing algorithm maximising the likelihood/ searching a MAP github.com/mschauer/Cau...github.comGitHub - mschauer/Causality-Lecture: These slides are from a guest lecture on causal discovery. They show how independence patterns, Gaussian SEMs, and interventions constrain causal structure. No pri...These slides are from a guest lecture on causal discovery. They show how independence patterns, Gaussian SEMs, and interventions constrain causal structure. No prior causal inference background ass... 120
Moritz Schauer @mschauer.bsky.social · 15/02/2026For me for a song to click there must be specific harmonic patterns present, you have them in m.youtube.com/watch?v=EKe9... for example but also in the notorious C&A song m.youtube.com/watch?v=UFDn...m.youtube.comNina Hagen - Du hast den farbfilm Vergessen (Subtitulado)YouTube video by PakoChile 020
Moritz Schauer @mschauer.bsky.social · 15/02/2026And some point I had to notice how many songs I like are David Bowie covers and I suspect David Bowie is too genius for me. This one for example, I can understand it through Nirvana, which are probably also geniuses though www.youtube.com/watch?v=freg...,youtube.comNirvana - The Man Who Sold The World (MTV Unplugged)YouTube video by NirvanaVEVO 250