Three natural fairness criteria for an AI classifier — calibration, equal false positive rates, equal false negative rates — cannot all hold simultaneously when base rates differ across groups. This is not an engineering failure. It is a theorem. Choosing which criterion to satisfy is a political decision, not a technical one.
The classroom videography manual we published in 2023 was about filming teaching. Music education has the same word in it — teaching — but it is a fundamentally different recording challenge. Sound is the subject matter. The lesson is often one person, in a practice room. And the feedback cycle the teacher needs to reach is mostly the one that happens when no camera is present. A reflection on what the manual missed, and a software prototype that tries to address part of it.
Every ensemble faces the same physical problem: N oscillators with slightly different natural frequencies trying to synchronise through a shared coupling channel. The Kuramoto model — developed by a statistical physicist to describe fireflies, neurons, and power grids — applies directly to musicians. It predicts a phase transition between incoherence and synchrony, quantifies why latency destroys networked ensemble performance, and connects to recent EEG studies of inter-brain synchronisation.
Danny Carey calls it sacred geometry. Gauss proved it non-constructible. They are, unexpectedly, describing the same object.
Why does the octave divide into twelve? The answer lies not in aesthetics but in the continued-fraction convergents of log₂(3/2) — and the same group structure that gives Messiaen his modes.
The same structural reason a toddler cannot put shoes on before socks is why position and momentum cannot be simultaneously measured. Non-commutativity is not exotic physics — it is the default logic of any ordered world.
On July 22, 2023, a Korean preprint claimed that LK-99 — a copper-doped lead apatite — was a room-temperature, ambient-pressure superconductor. Within six weeks, the claim was definitively falsified. The episode is more interesting for what it revealed about the sociology of science than for the compound itself: how a global community self-corrected at extraordinary speed, and how the media managed to fail at conveying uncertainty despite watching it happen in real time.
A cat dropped upside-down rotates 180° and lands on its feet, despite having zero angular momentum throughout. This is not a trick and not a violation of physics. The explanation took physicists from 1894 to 1993 to fully work out, and the answer — a geometric phase arising from the holonomy of a fiber bundle — is the same mathematics that governs the Berry phase in quantum mechanics and the Aharonov-Bohm effect in electrodynamics. We adopted two strays this year. They fall beautifully.
Every classroom treatment of exoplanet detection focuses on the transit method. What gets omitted is that moons of exoplanets could also host life — and that with a small motor and a slight modification to the standard transit experiment, you can show students what an exomoon signature looks like in a light curve. Published in MNU Journal in 2023.
We measured end-to-end audio and video latency for LoLa and MVTP across six European research-network links. One-way audio latency ranged from 7.5 to 22.5 ms. Routing topology mattered more than geographic distance. Enterprise firewalls were a disaster. Here is what we found.