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How "The Power" Literally Rocked the House

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Turbo B and Penny Ford, featured performers on "The Power"

On July 5, 2011, the 39-story "Techno-Mart" mall in Seoul, South Korea shook for ten minutes, causing a two-day evacuation and an investigation. The cause of the tremors? Seismic experts concluded that "The Power," a dance hit by the band Snap!, simply rocked too hard.

Tae Bo Power - It's Gettin' Kinda Hectic

When the shaking occurred, it was felt only in the upper floors of the Techno-Mart. An investigation revealed that several dozen people had been doing an intense Tae Bo workout on the 12th floor. On that day, the Tae Bo instructor put on "The Power" and urged the class to do their workout "twice as hard." All that rhythmic stomping set up mechanical resonance within the building, causing it to vibrate. The Techno-Mart happened to have a resonance frequency matching that of "The Power's" kickin' beat. Here's a bit more explanation by professor Chung Lan of Dankook University:

“It just happens to be that the vibration set up by the “taebo” [sic] exercises coincided with the resonance frequency unique to the building,” the professor said. When an external vibration hits the resonance frequency of a certain object, the vibration is amplified and causes excess shaking even from slight movement.

And lest we forget, here's "The Power":

Rhythm is a Dancer

It's important to emphasize that the Techno-Mart's shaking was caused not so much by the weight of the stompers, but by their rhythm (ahem, "Rhythm is a Dancer" is also a song by Snap!). Investigators demonstrated that "The Power" was the song with the building-busting beat by staging a second dance session, while tremor detectors were installed throughout the building. Yes, Korean scientists recruited a new set of "middle-aged people" who performed Tae Bo to "The Power" for the sake of public safety. Here's a snippet from Koea JoongAng Daily:

Jeong Ran, a professor at Dankook University, said, “The total weight of the people who are expected to participate in the demonstration will be about 850 kilograms (1,873 pounds). But, actually, weight is not that important. Rhythm and music causes tremors. The demonstrators are now practicing how to dance to the beat of the music.

The original group of Tae Bo enthusiasts refused to come forward, for fear of negative media attention. Apparently the Tae Bo instructor also disappeared, and to make things worse, the incident occurred during his first day on the job.

The supreme irony of this is that Billy Blanks, creator of the Tae Bo workout system, released a video called Tae Bo Power later in 2011. The video featured a section on attaining "Billy's Power Abs" and encouraged users to "feel the POWER." It did not, however, cry "I've got the power!"


Original 45rpm "The Power" single

Zumba Can Also Rock Super-Hard

An oddly similar incident occurred in February 2011 in Australia, although instead of Tae Bo, the exercise was Zumba -- a mix of dance and aerobics. In Canberra, an Education Department building shook violently after a 12th floor dance class got its groove on. According to a story in The Age (emphasis added):

Tests confirmed exercise classes were causing the building to shake. While all buildings are designed to move in response to factors such as wind, the high impact movements of Zumba caused a build-up of "harmonic vibrations", despite the floor on which the exercise class was held exceeding Australian standards for gymnasiums, officials said.

As a result, Zumba classes were stopped in the building because of safety fears.

Snap! Bonus Trivia

You may have wondered about the brief Russian snippet in the beginning of the music video for "The Power." It appears to be a man talking about the Sputnik satellites, but indeed is about the release of a personal computing device for the visually impaired. (In Russian, the term "sputnik" is not specific to the iconic Russian satellites -- it means, roughly, "fellow traveler.") Wikipedia explains the opening clip:

The song opens with the somewhat enigmatic line in Russian: “???????????? ????? Transceptor Technology ?????????? ? ???????????? ??????????? «???????????? ???????»” (meaning “The American company Transceptor Technology has started production of the ‘Personal Companion’ computer”). “Personal Companion” was a computer-like device for the blind and visually impaired. Released in 1990, it was controlled by voice and could, among other functions, automatically download articles from USA Today by a built-in modem. It was made by Transceptor Technologies of Ann Arbor, Michigan.

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iStock // Ekaterina Minaeva
technology
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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iStock
Animals
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Scientists Think They Know How Whales Got So Big
May 24, 2017
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iStock

It can be difficult to understand how enormous the blue whale—the largest animal to ever exist—really is. The mammal can measure up to 105 feet long, have a tongue that can weigh as much as an elephant, and have a massive, golf cart–sized heart powering a 200-ton frame. But while the blue whale might currently be the Andre the Giant of the sea, it wasn’t always so imposing.

For the majority of the 30 million years that baleen whales (the blue whale is one) have occupied the Earth, the mammals usually topped off at roughly 30 feet in length. It wasn’t until about 3 million years ago that the clade of whales experienced an evolutionary growth spurt, tripling in size. And scientists haven’t had any concrete idea why, Wired reports.

A study published in the journal Proceedings of the Royal Society B might help change that. Researchers examined fossil records and studied phylogenetic models (evolutionary relationships) among baleen whales, and found some evidence that climate change may have been the catalyst for turning the large animals into behemoths.

As the ice ages wore on and oceans were receiving nutrient-rich runoff, the whales encountered an increasing number of krill—the small, shrimp-like creatures that provided a food source—resulting from upwelling waters. The more they ate, the more they grew, and their bodies adapted over time. Their mouths grew larger and their fat stores increased, helping them to fuel longer migrations to additional food-enriched areas. Today blue whales eat up to four tons of krill every day.

If climate change set the ancestors of the blue whale on the path to its enormous size today, the study invites the question of what it might do to them in the future. Changes in ocean currents or temperature could alter the amount of available nutrients to whales, cutting off their food supply. With demand for whale oil in the 1900s having already dented their numbers, scientists are hoping that further shifts in their oceanic ecosystem won’t relegate them to history.

[h/t Wired]

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