51动漫

Feedback is our weekly column of bizarre stories, implausible advertising claims, confusing instructions and more

Bloons and doubloons

This edition of Feedback is an exercise in time travel 鈥� in that every item is something from absolutely ages ago that we somehow missed. We would feel guilty, but it is the summer holidays (in the northern hemisphere, anyway) and many readers will have half an eye on their errant children, so we thought we could get away with it.

So, cast your minds back to 2008. This, obviously, was the year of the 20th Canadian Conference on Computational Geometry, . A large amount of research was at this conference, but reporter Matthew Sparkes recently stumbled across a by Erik Demaine, Martin Demaine and Vi Hart. It presents 鈥渁 general mathematical and algorithmic theory for balloon-twisting structures鈥�.

If you didn鈥檛 grasp that, allow us to clarify: it鈥檚 about the geometry of balloon animals. The authors develop a mathematical framework that allows them to calculate how many balloons you need to generate a particular shape, whether it is a dog (one) or some complicated polyhedron like a dodecahedron (10). These, naturally, are referred to as 鈥淧latonic balloons鈥�.

Throughout the paper, the authors use the term 鈥渂loon鈥� to refer to a mathematical entity equivalent to a balloon. Feedback wasn鈥檛 clear why this neologism was necessary, until we realised that they were therefore able to refer to a balloon of twice the usual length as a 鈥渄oubloon鈥�.

Curious to know what the authors had been up to since, Feedback went a-searching. Hart became a science populariser on YouTube, then a senior manager at Microsoft. Meanwhile, Martin and Erik are father-and-son researchers and artists, both fascinated by the mathematics of folding.

Erik, a professor at the Massachusetts Institute of Technology, has been in 51动漫 a lot. Recent papers include 鈥溾�� and 鈥溾��. More from Erik, please.

Testing times

Continuing on the topic of being very late to things, reader Derek Long flagged a paper from 2018, 鈥� and major trauma when jumping from aircraft: randomized controlled trial鈥�. It reports on a study called 鈥淧Articipation in RAndomized trials Compromised by widely Held beliefs aboUt lack of Treatment Equipoise (PARACHUTE)鈥�.

(Side note: that is a truly excellent scientific acronym. We haven鈥檛 had any of those in a while.)

The problem posed is one of evidence. 鈥淧arachutes are routinely used to prevent death or major traumatic injury among individuals jumping from aircraft. However, evidence supporting the efficacy of parachutes is weak and guideline recommendations for their use are principally based on biological plausibility and expert opinion.鈥� If readers haven鈥檛 yet twigged: the paper is satirical, poking fun at the idea that even the most common-sense interventions should be tested in a full randomised controlled trial.

As the authors write: 鈥淚n seminal work published in the BMJ in 2003, a systematic search by Smith and Pell for randomized clinical trials evaluating the efficacy of parachutes during gravitational challenge yielded no published studies.鈥�

Feedback actually ran across that back in 2004. The authors noted they were 鈥渦nable to identify any randomised controlled trials of parachute intervention鈥� and suggested that 鈥渆veryone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute鈥�. Oof.

Fifteen years later, they did do a trial. This showed that 鈥減arachute use did not significantly reduce death or major injury鈥�, with the slight caveat that 鈥渢he trial was only able to enroll participants on small stationary aircraft on the ground鈥�. This was helpfully illustrated by a photo of one of the participants jumping, parachute-less, out of a grounded plane. As the authors say: 鈥淥ur findings should give momentary pause to experts who advocate for routine use of parachutes for jumps from aircraft in recreational or military settings.鈥�

Witty Zwicky

Some concepts can鈥檛 be traced back to their origins. One such is the spherical cow joke, which illustrates the difficulties of working with highly simplified and abstract models of complicated, real-world situations. It involves a physicist who figures out how to improve productivity on a dairy farm, but their solution only works for spherical cows in a vacuum. Nobody seems to know who came up with this: the oldest references place it , but the origin stories are all vague and one reference the cows with chickens.

However, another sphere-based physicist joke seems to be older. Feedback has just learned, many decades after the fact, about an insult deployed by Fritz Zwicky, who, in the 1930s, produced some of the first evidence for dark matter. A noted curmudgeon, Zwicky was fond of referring to people he disliked as 鈥渟pherical bastards鈥�. Such a person is a bastard no matter which way you look at them.

Feedback will be using that from now on. But we also want to know the etymology (if that is quite the term) of spherical bastards, chickens and cows. Any insights welcome.

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