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Mathematician Calculates Rotational Speed of Fidget Spinner in Fidgets Per Second

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How fast does a fidget spinner spin? It's a simple question with a simple answer, but a complex path to that answer. The issue lies in analyzing an extremely fast-moving object with simple tools, like a smartphone.

In the video below, mathematician Matt Parker turns to a spectrogram sound-analyzing app to solve this problem. Spectrograms are visual representations of sound, allowing the viewer to pick out certain frequencies within an audio clip and measure their intensity. By figuring out the sound the fidget spinner makes, Parker can sort out how many Hertz (cycles per second) the spinner is rotating at.

The first task is making the spinner itself stable, so it's easy to spin and becomes a reliable target for audio recording. Parker attaches the device to a drinking glass, and mounts the smartphone above it, with the microphone pointed at the edge of the spinner. Then by blowing the fidget spinner with compressed air, the mathemagic happens.

Parker calculates the absolute speed of the tips of the fidget spinner, as well as the speed of the spinner in revolutions per minute—the latter is roughly 3750 rpm! (For comparison, a typical car engine runs around 2000-3000 rpm when cruising.) The video is full of further analysis and methodology.

Tune in for some delightful applied mathematics...and be sure to wear your safety gear!

Incidentally, Parker used the SpectrumView app, though there are others like it. He also posted a screenshot of the spectrogram, as seen in the video, in case you want to test your own spinner.

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Watch Boris Karloff's 1966 Coffee Commercial
TAKWest, Youtube
TAKWest, Youtube

Horror legend Boris Karloff is famous for playing mummies, mad scientists, and of course, Frankenstein’s creation. In 1930, Karloff cemented the modern image of the monster—with its rectangular forehead, bolted neck, and enormous boots (allegedly weighing in at 11 pounds each)—in the minds of audiences.

But the horror icon, who was born 130 years ago today, also had a sense of humor. The actor appeared in numerous comedies, and even famously played a Boris Karloff look-alike (who’s offended when he’s mistaken for Karloff) in the original Broadway production of Arsenic and Old Lace

In the ’60s, Karloff also put his comedic chops to work in a commercial for Butter-Nut Coffee. The strange commercial, set in a spooky mansion, plays out like a movie scene, in which Karloff and the viewer are co-stars. Subtitles on the bottom of the screen feed the viewer lines, and Karloff responds accordingly. 

Watch the commercial below to see the British star selling coffee—and read your lines aloud to feel like you’re “acting” alongside Karloff. 

[h/t: Retroist]

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Watch a Chain of Dominos Climb a Flight of Stairs
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Dominos are made to fall down—it's what they do. But in the hands of 19-year-old professional domino artist Lily Hevesh, known as Hevesh5 on YouTube, the tiny plastic tiles can be arranged to fall up a flight of stairs in spectacular fashion.

The video spotted by Thrillist shows the chain reaction being set off at the top a staircase. The momentum travels to the bottom of the stairs and is then carried back up through a Rube Goldberg machine of balls, cups, dominos, and other toys spanning the steps. The contraption leads back up to the platform where it began, only to end with a basketball bouncing down the steps and toppling a wall of dominos below.

The domino art seems to flow effortlessly, but it took more than a few shots to get it right. The footage below shows the 32nd attempt at having all the elements come together in one, unbroken take. (You can catch the blooper at the end of an uncooperative basketball ruining a near-perfect run.)

Hevesh’s domino chains that don't appear to defy gravity are no less impressive. Check out this ambitious rainbow domino spiral that took her 25 hours to construct.

[h/t Thrillist]

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