Asking the wrong questions: still no evidence of a sonic weapon

Back in October, AP reported that they had “obtained a recording of what some U.S. Embassy workers heard in Havana,” a high-pitched whine “sort of like a mass of crickets.”

A new technical report tests the idea that the audible sounds recorded by AP in Cuba could have been caused by two (or more) ultrasonic sources (a less technical description is here). What the paper shows is that sounds similar to those in the AP report can be produced from the interference of one ultrasonic source on another. This much seems convincing. I don’t have a deep understanding of the physics, but the real-world demonstration is hard to argue with.

But just because the sound can be reproduced this way doesn’t mean it was produced this way. I have seen “Eye of the Tiger” played on dot matrix printers. That doesn’t mean Survivor recorded it using dot matrix printers.

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That beautiful animalcule: Andrew Pritchard on Volvox

Pritchard figure

Plate from Pritchard 1834. Image from Google Books.

Andrew Pritchard’s 1834 book The Natural History of Animalcules includes several species he classifies as Volvox. Most of them were probably not Volvox, but his Volvox globator certainly was. His description of Volvox begins on page 39. A scanned version is available online at The Biodiversity Heritage Library, but I have used the slightly higher quality scan in Google Books for the plate above.

The animalcules belonging to this genus are of a globular form, and revolve in the water. Some of the species are so large as to be discerned by unassisted vision, while others are very diminutive. Ehrenberg has not demonstrated their digestive organization; but in a note to his table, conceives they ought to follow the monads. In this genus is included that beautiful animalcule, called the Volvox globator, which forms so interesting a spectacle in the Solar and Gas Microscopes.

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This is how you do it

I’m pretty annoyed with CNN these days. I have called them “recklessly irresponsible” for failing to apply the slightest skepticism to the administration’s absurd claims of sonic weapon attacks in Cuba. Then there’s their website’s autoplay videos, which shrink, move to the sidebar, and keep playing if you scroll past them. Because obviously, when you scroll past a video to read a story, what you want is to see the video.

But Brianna Keilar nails it in this interview with Georgia State Senator Michael Williams:

That’s right, she asked the exact question I’ve criticized CNN for failing to ask: how do you know that? And Senator Williams dances a beautiful little jig in his effort to dodge her question.

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Zombie Volvox on PhysOrg

Ueki & Wakabayashi Fig. 4A-C

Figure 4A-C from Ueki and Wakabayashi 2018. Ca2+-dependent changes in the direction of axonemal beating. (A) Experimental setups for observation of live or demembranated spheroids in a chamber. (B) Frames from high-speed recordings of regions near the anterior (Top) and posterior (Bottom) poles of a live spheroid. The observation using setup A was under stationary conditions in continuous light (Left) and after photostimulation (Right). (Scale bar: 100 μm.) (C) Typical sequential flagellar waveforms in a single beating cycle under each condition. Waveforms recorded as in B were traced (time interval of 1/500 s). (Scale bar: 10 μm.).

Last month, I reported on mad scientists Noriko Ueki and Ken-ichi Wakabayashi’s reanimation of dead (demembranated) Volvox rousseletii spheroids. PhysOrg is also carrying the zombie Volvox story:

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Volvox 2019 dates and location

The Fifth International Volvox Conference will be held at the University of Tokyo July 26-29, 2019, hosted by Professor Hisayoshi Nozaki. The tentative schedule is as follows:

Friday 26 July 2019
Registration and welcoming reception and poster set up.

Saturday 27 July 2019
Oral session and Poster session

Sunday 28 July 2019
Oral session
Dinner party

Monday 29 July 2019
One day and/or half day trips to Volvox-field collection/algal culture collection at NIES etc. (not determined).

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Flagellar synchronization in Chlamydomonas

The physics is way beyond me, but a new paper by Gary Klindt and colleagues in New Journal of Physics uses Chlamydomonas as a model for flagellar synchronization:

We present a theory of flagellar synchronization in the green alga Chlamydomonas, using full treatment of flagellar hydrodynamics and measured beat patterns. We find that two recently proposed synchronization mechanisms, flagellar waveform compliance and basal coupling, stabilize anti-phase synchronization if operative in isolation. Their nonlinear superposition, however, can stabilize in-phase synchronization for suitable parameter choices, matching experimental observations.

Klindt et al. Fig. 1

Figure 1 from Klindt et al. 2017. In-phase and anti-phase synchronization. (a) In-phase synchronization at high synchronization strength, corresponding to “breast-stroke swimming” Chlamydomonas. (b) For low synchronization strength, anti-phase synchronization is stable, corresponding to a “free-style” gait.

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