Mathematician Calculates Rotational Speed of Fidget Spinner in Fidgets Per Second

iStock // fullempty
iStock // fullempty

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.

10 LEGO Sets For Every Type of LEGO Builder 

Amazon
Amazon

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If you’re looking for a timeless gift to give this holiday season, look no further than a LEGO set. With kits that cater to a wide age range—from toddlers fine-tuning their motor skills to adults looking for a more engaged way to relax—there’s a LEGO set out there for everyone. We’ve rounded up some of our favorite sets on Amazon to help you find the LEGO box that will make your loved one smile this year. If you end up getting one for yourself too, don’t worry: we won’t tell.

1. Classic Large Creative Gift Box; $44

Amazon

You can never go wrong with a classic. This 790-piece box contains dozens of types of colored bricks so builders of any age can let their inner architect shine. With toy windows, doors, tires, and tire rims included in addition to traditional bricks, the building possibilities are truly endless. The bricks are compatible with all LEGO construction sets, so builders have the option of creating their own world or building a new addition onto an existing set.

Buy it: Amazon

2. Harry Potter Hogwarts Express; $64

Amazon

Experience the magic of Hogwarts with this buildable Hogwarts Express box. The Prisoner Of Azkaban-inspired kit not only features Hogwarts's signature mode of transportation, but also Platform 9 ¾, a railway bridge, and some of your favorite Harry Potter characters. Once the train is built, the sides and roof can be removed for play within the cars. There is a Dementor on board … but after a few spells cast by Harry and Lupin, the only ride he’ll take is a trip to the naughty list.

Buy it: Amazon

3. Star Wars Battle of Hoth; $160

Amazon

Star Wars fans can go into battle—and rewrite the course of history—by recreating a terrifying AT-AT Walker from the Battle of Hoth. Complete with 1267 pieces to make this a fun challenge for ages 10 and up, the Walker has elements like spring-loaded shooters, a cockpit, and foldout panels to reveal its deadly inner workings. But never fear: Even though the situation might look dire, Luke Skywalker and his thermal detonator are ready to save the day.

Buy it: Amazon

4. Super Mario Adventures Starter Course; $60

Amazon

Kids can play Super Mario in 3D with LEGO’s interactive set. After constructing one of the courses, young designers can turn on the electronic Mario figurine to get started. Mario’s built-in color sensors and LCD screens allow him to express more than 100 different reactions as he travels through the course. He’ll encounter obstacles, collect coins, and avoid Goomba and Bowser to the sound of the Mario soundtrack (played via an included speaker). This is a great gift for encouraging problem-solving and creativity in addition to gaming smarts.

Buy it: Amazon

5. Gingerbread House; $212

Amazon

Gingerbread houses are a great way to enjoy the holidays … but this expert-level kit takes cookie construction to a whole new level. The outside of the LEGO house rotates around to show the interior of a sweet gingerbread family’s home. Although the living room is the standout with its brick light fireplace, the house also has a kitchen, bedroom, bathroom, and outdoor furniture. A LEGO Christmas tree and presents can be laid out as the holidays draw closer, making this a seasonal treat you can enjoy with your family every year.

Buy it: Amazon

6. Elsa and Olaf’s Tea Party; $18

Amazon

LEGO isn’t just for big kids. Toddlers and preschoolers can start their LEGO journey early by constructing an adorable tea party with their favorite Frozen characters. As they set up Elsa and Olaf’s ice seats, house, and tea fixings, they’ll work on fine-motor, visual-spatial, and emotional skills. Building the set from scratch will enable them to put their own creative spin on a favorite movie, and will prepare them for building more complicated sets as they get older.

Buy it: Amazon

7. Collectible Art Set Building Kits; $120

Amazon

Why buy art when you can build it yourself? LEGO’s Beatles and Warhol Marilyn Monroe sets contain four options for LEGO art that can be built and displayed inside your home. Each kit comes with a downloadable soundtrack you can listen to while you build, turning your art experience into a relaxing one. Once you’re finished building your creation it can be exhibited within a LEGO brick frame, with the option to hang it or dismantle it to start on a new piece. If the 1960s aren’t your thing, check out these Sith and Iron Man options.

Buy it: Amazon

8. NASA Apollo Saturn V; $120

Amazon

The sky (or just the contents of your LEGO box) is the limit with LEGO’s Saturn V expert-level kit. Designed for ages 14 and up, this to-scale rocket includes three removable rocket stages, along with a command and service module, Lunar Lander, and more. Once the rocket is complete, two small astronaut figurines can plant a tiny American flag to mark a successful launch. The rocket comes with three stands so it can be displayed after completion, as well as a booklet for learning more about the Apollo moon missions.

Buy it: Amazon

9. The White House; $100

Amazon

Reconstruct the First Family’s home (and one of America’s most famous landmarks) by erecting this display model of the White House. The model, which can be split into three distinct sections, features the Executive Residence, the West Wing, and the East Wing of the complex. Plant lovers can keep an eye out for the colorful rose garden and Jacqueline Kennedy Garden, which flank the Executive Residence. If you’re unable to visit the White House anytime soon, this model is the next best thing.

Buy it: Amazon

10. Volkswagen Camper Van; $120

Amazon

Road trip lovers and camping fanatics alike will love this vintage-inspired camper. Based on the iconic 1962 VW vehicle, LEGO’s camper gets every detail right, from the trademark safari windshield on the outside to the foldable furniture inside. Small details, like a “Make LEGO Models, Not War” LEGO T-shirt and a detailed engine add an authentic touch to the piece. Whether you’re into old car mechanics or simply want to take a trip back in time, this LEGO car will take you on a journey you won’t soon forget.

Buy it: Amazon

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Watch: In 1948, Idaho Officials Sent 76 Beavers Parachuting Into Idaho’s Wilderness

A young beaver with all four feet firmly on the ground.
A young beaver with all four feet firmly on the ground.
yrjö jyske, Flickr // CC BY 2.0

When people started building up the area around Idaho’s Payette Lake after World War II, its original residents began interfering with irrigation and agricultural endeavors. They weren’t exactly staging an organized protest—they were just beavers doing what beavers do.

Nevertheless, officials at the Idaho Department of Fish and Game decided their best bet was to find a new home for the long-toothed locals. The surrounding wilderness provided plenty of options, but transportation was another issue entirely. Traversing the undeveloped, mountainous terrain would require both trucks and pack animals, and experts knew from past relocation efforts that beavers weren’t fond of either.

“Beavers cannot stand the direct heat of the sun unless they are in water,” department employee Elmo W. Heter explained in a 1950 report [PDF]. “Sometimes they refuse to eat. Older individuals often become dangerously belligerent ... Horses and mules become spooky and quarrelsome when loaded with a struggling, malodorous pair of live beavers.”

To keep Payette Lake’s beavers healthy and happy during the journey, their human handlers would need to find another method of travel. As Boise State Public Radio reports, that’s when Heter suggested making use of their leftover WWII parachutes.

Two beavers would sit inside a wooden box attached to a parachute, which could be dropped from an airplane between 500 and 800 feet above their new home in the Chamberlain Basin. The cables that fastened the box to the parachute would keep it shut during the flight, but they’d slacken enough for the beavers to open the box upon landing. After testing the operation with weights, Heter and his colleagues enlisted an older beaver named Geronimo for a few live trials.

“Poor fellow!” Heter wrote. “You may be sure that ‘Geronimo’ had a priority reservation on the first ship into the hinterland, and that three young females went with him.”

Once Geronimo had certified the safety of the mission, the team began migrating the whole beaver population. During the fall of 1948, a total of 76 beavers touched down in their new territory. It wasn’t without tragedy, though; one beaver fell to his death after a cable broke on his box. Overall, however, the venture was deemed much safer (and less expensive) than any trip on foot would have been. And when department officials checked in on the beavers a year later, they had already started improving their ecosystem.

“Beavers had built dams, constructed houses, stored up food, and were well on their way to producing colonies,” Heter wrote. As Idaho Fish and Game’s Steve Liebenthal told Boise State Public Radio, the area is now part of “the largest protected roadless forest” in the continental U.S.

You can watch the Idaho Fish and Game Commission’s full 14-minute documentary about the process below.

[h/t Boise State Public Radio]