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Why scientists are dropping fake birds onto fake planes

Mid-air collision

To learn whether air taxi passengers need worry about collisions with birds, a crash programme in Germany did some tests.

What with the complexity and danger of having actual air taxis have congress with actual birds, perfection was out of reach. So the experimenters made do, dropping artificial “bird projectiles” onto a metal plate rigged to measure the impact force.

Aditya Devta and Isabel Metz at the German Aerospace Center and Sophie Armanini at the Technical University of Munich describe these violent encounters in a preprint article. (Thanks to reader Mason Porter for alerting us to it.)

This work was, of necessity, a rough step towards reliably answering the big question.

It encountered difficulties, starting with “inconsistencies and lack of repeatability due to human involvement as the bird projectiles were dropped manually by hand”. Future efforts, the report says, “will eliminate the human involvement [so as to] increase accuracy in force measurements and repeatability”.

Mid-track collision

Speaking of birds-and-air-taxis-ish experiments, have you heard the one about the moose and the bullet train? Yong Peng and his colleagues at Central South University in China have begun to examine what might happen when these heavyweights meet at high speed, in the paper “Analysis of moose motion trajectory after bullet train-moose collisions“.

The question involves more than the initial, simple impact. The scientists mention two not-unlikely complications: “A moose lying on a track after a crash may increase the risk of train derailment” and “a moose thrown into the air during a collision may also hit and damage the pantograph, which prevents a train from running”.

The investigation so far has been done with finite-element mathematical simulations and some not-very-heavyweight experiments. The experiments used fresh beef – beef from cows, not moose – muscle tissue and a kind of stress-strain testing machine known as a “split-Hopkinson pressure bar”.

The scientists report that, essentially, the impact force “depends on the contact area between the train and the moose”.

As to those complications: “The moose would be pushed away by the V-shaped locomotive and would not cause a derailment, and the height of the moose thrown into the air cannot reach the height of the pantograph, which would prevent damage to the pantograph of a bullet train.”

The study suggests that bigger things are approaching: “only the scenario of a train impacting a moose across a track at a speed of 110 km/h was simulated, which cannot fully reflect the risks of train-moose collisions. Thus, more speeds and postures are needed to enhance our study, which is ongoing.”

Feeling saucy

Slowly, sweetly, new sauce insights pour in from readers. These pertain to the off-label usage of ketchup and other sticky foodstuffs to make electrocardiogram (ECG) electrodes work well (Feedback, 25 May).

Brian Reffin Smith adds a musical note: “You don’t need human skin to test whether electrodes work better with ketchup than with official gel. I have a device which applies a low voltage to plant leaves (or anything else) and then translates the varying current into MIDI signals, sent to a computer or synthesiser to trigger sounds… Anyway, statistically insignificant but anecdotally and culinarily interesting tests reveal that a reduced salt ketchup applied between ECG electrodes and a chilli plant’s leaf produced a quite high E, whilst the proper gel on a neighbouring leaf played G. I thought this might help, but now I don’t think so.”

Dave Hardy contributes a practicality claim: “My GP in the early 1970s said that the gel was ridiculously expensive, but strawberry jam worked just as well. I don’t know if he’d experimented with different options or just used what he had to hand. (This was in the Falkland Islands.)”

Star deaths stars

It’s surprising how few people are hailed as being a “celebrity pathologist”, isn’t it? The Associated Press brings news of the death of one of them: “Dr. Cyril Wecht, celebrity pathologist who argued more than 1 shooter killed JFK, dies at 93”.

One of the first celebrity pathologists, Bernard Spilsbury (1877-1947), helped establish London’s reputation as the go-to place for entertainingly clever murder mystery investigations.

The Royal College of Physicians made clear, postmortemly, that Spilsbury’s career was quite theatrical: “The famous Crippen trial, on which he worked with [William] Wilcox to show that the murder was due to hyoscine hydrobromide, brought him the first blaze of publicity which he deplored in every succeeding trial at which he appeared, and this was undoubtedly why he assumed an austere and frigid manner to all but his intimate friends.”

Spilsbury’s manner was nothing to sniff at. One aspect of postmortem work – the dreadful stink of decaying dead bodies – deters sensitive people from entering the profession. Spilsbury wasn’t a sensitive person in that respect. His peers marvelled at what an obituary politely said was a “defective sense of smell”.

Marc Abrahams created the Ig Nobel Prize ceremony and co-founded the magazine Annals of Improbable Research. Earlier, he worked on unusual ways to use computers. His website is improbable.com

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