tiny triboelectric discharges
One of these just for including that comment in the piece! --->
Harvard boffins finally crack the mystery of squeaky sneakers
It is a sound evocative of high school: the characteristic squeak of sneakers on a basketball court. UK readers may, however, be familiar with the same sound from their trainers while playing badminton. Whichever it is, how exactly the sound is produced has been a mystery - until now. The high-pitched tones have often been …
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Saturday 28th February 2026 16:26 GMT Bill Gray
Applications?
I can see why people would immediately think "Ig Nobel prize material", but I could see a few uses for this.
My partner in joys and sorrows teaches violin lessons, so the comment in The Fine Article about "the sound of a violin bow moving against... [a] string" caught my attention. My office is in the room next to her studio, so I frequently hear beginning players struggle to get that bit to sound good. [0] There are inevitable "strangling cat" noises produced before they get the hang of it.
If I were a manufacturer of violin bows or strings, I might take an interest in this research.
Similarly, anyone using rubber for braking (bicycle brakes, sneaker manufacturers, etc.) might be able to learn something from this. Maybe to make the brakes less noisy, or abrade less, or be quieter, or stop you quicker.
[0] You get used to it pretty quickly.
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Sunday 1st March 2026 19:26 GMT cd
Re: Applications?
Bicycle rim brake shoes can be quieted by toeing-in so the application is graduated, been practiced for decades. Shoes from the 1970s sometimes had that capability built-in to the mounting, or one tweaked the arms a bit.
Disc brake pads on cars and motorcycles often include dampening shims and goop layers on the back side, which work so well that pads routinely wore through to the metal backing plate, causing overheating and damage.
As a result of that, many pads are equipped with a metal tongue that contacts the brake disk and starts squeaking when the pad reaches replacement wear level.
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Monday 2nd March 2026 00:02 GMT Ropewash
Re: Applications?
Reminds me of an old pickup truck I owned in my youth. Rusty rotor cut right through the pad, the backing plate and into the piston surface. I'd grown so used to the noise that I didn't bother to check until it went from squawking to crunching. Many hours of dirt-backlot repairs later a lesson was learned.
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Monday 2nd March 2026 03:10 GMT The Organ Grinder's Monkey
Re: Applications?
I'm guessing that there will have been a significant reduction in braking when the disc went metal-to-metal with the pad's backing, & as that's unlikely to have happened simultaneously on both sides of the vehicle it should have pulled violently to one side under braking 'till the other side wore through too?
I'm assuming too that, this being an old truck, it would have had drum brakes on the rear, so this must have been a front brake, so that pull would usually be violent enough to break your grip on the steering wheel if braking hard.
There's a couple of YouTube channels that just post compilations of "you wouldn't believe what I found on a customers car today" clips from mechanics. Brake discs worn through such that the pads are running on the disc's exposed cooling fins is commonplace, as are discs that have parted company from their bells. Most horrifying is the "customer declined repairs" caption on some absolute deathtraps. A high proportion of those seem to be from the US. Presumably some states have no annual safety testing? Can that really be true in 2026? France used to be the same, but there, if you had a crash & your vehicle was found to be defective, they really threw the book at you.
From memory "Just rolled in" & "mechanical nightmares" are two of the better channels.
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Monday 2nd March 2026 00:50 GMT Bill Gray
Re: Applications?
I think the "noisemaker" bit has become quite common. My recent cars (and I drive old junk) have alerted me in that manner, and my mechanic confirmed that I'd heard the "warning noises" rather than "take out a bank loan" noises. Basically the same idea as having a cheap fuse blow out rather than expensive hardware. (Except that usually, the expensive hardware sacrifices itself to save the cheap fuse.)
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Biting the hand that feeds IT
