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[2026-10-06] · src Quanta Magazine, S. Ornes, 2026-10-02 (found the story); primary: L. Fang, X. Si, PNAS Nexus 3(2), pgae056 (2024), doi:10.1093/pnasnexus/pgae056; and a 2025 Science Advances paper with F. De Lillo and G. Boffetta, doi:10.1126/sciadv.adv0956 (neither read)
In two-dimensional turbulence energy conventionally cascades inversely, from small to large scales. Per Quanta's account of the Fang/Si and De Lillo/Boffetta work, an elongated swimmer about 1 cm long (brine shrimp, or a rod) can reverse this locally, and the sign depends on its orientation. The coupling is between the large-scale strain-rate tensor and the small-scale stress the swimmer injects, and their alignment decides the direction. Below about 45° to the axis of maximum stretching energy goes to larger scales, above it to smaller ones. Quanta also reports that steering swimmers to act as transport barriers needs under 1% of the flow's energy. I could not check error bars, Reynolds numbers or the experimental-versus-simulation split, so treat these as secondhand.
It would give a geometric, orientation-based control knob on the cascade direction, relevant to active matter and to plankton mixing in thin layers. Little yet for general turbulence: this is 2D, with an idealised swimmer, and the quantitative claims here rest on press coverage. Read the Science Advances paper's sections on the 45° criterion and on whether real 3D swimming departs from it.
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[2026-10-06] · src —
Trumpet takes today: three days since it was last assigned, the longest gap of the three, and the last session was a long one. With the 14 Characteristic Studies finished, the work moves to the interval half of Arban's Scales & intervals section, kept short and in the comfortable register, paired with Art of Phrasing No. 28 as the melody. A brief, clean session is the aim.
5 minutes: long tones on written C, G and low C, 8 counts each at mp, starting each one without tongue accent, then a slow lip slur between adjacent partials at quarter = 60. Listen for a centred tone with no wobble at the start of the note.
Intervals from the Scales & intervals section: pick one interval study (thirds, then fourths) and play it slurred, in two keys, within the staff and a little above, no high-register reaching. Success criterion: three consecutive clean passes at quarter = 72, then 80, then 88, with every leap landing in the middle of the note on the first try.
Art of Phrasing No. 28: shape it in whole phrases, one breath per phrase. Find the high point of each phrase and let the line lean toward it and relax after, so the interval leaps from the technical work sound like singing rather than jumping.
Keep the session to about 30 minutes. Stop when the tone starts to spread or the lips feel flat or swollen, even if the tempo goal is not reached; stopping ten minutes early beats a ragged finish. No tonguing speed work or high-register work today.
[2026-10-06] · src —
hearClifford Brown & Max Roach — Joy Spring · Tidal · Spotify
Brown's line is full of leaps and scale runs, and every note is placed and even in tone. Listen to how the wide intervals keep the same sound as the stepwise passages, with no change of colour on the jump. That evenness is today's technical target, played by someone who had it.