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Wikimedia Commons (Trotsky) / iStock (Background)

The Gruesome Assassination of Leon Trotsky

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Wikimedia Commons (Trotsky) / iStock (Background)

In August 1940, a Russian expatriate worked in his well-sheltered garden in Mexico City. He surrounded himself with chickens, rabbits, and peaceful trees. But the man was no vacationing grandpa—he was one of the most famous political exiles in the world, and his home in Coyoacan was surrounded by armed guards and fortress-like walls.

Leon Trotsky had been a political liability in Russia for years before his hasty expulsion. Though he had helped lead the Communist Party to power in Russia during the Bolshevik revolution in 1917, Trotsky quickly became persona non grata to Joseph Stalin. Trotsky’s opposition to Stalin's bloated bureaucracy and his publicly-stated belief that Stalinism wasn’t taking Communism far enough toward permanent world revolution cost him everything. 

When Vladimir Lenin died in 1924, it was thought that Trotsky, who had endured a long marriage of political convenience with Lenin, might come to power. But Stalin helped drum up and took advantage of anti-Trotsky sentiment to seize Soviet control instead. Stalin acted swiftly against the former hero, and he swept Trotsky out of his political positions, the Communist Party, and eventually the USSR itself. 

As Trotsky looked for a new state to call home, Stalin scrubbed him from photographs and published texts, but Trotsky was more concerned about preserving his actual life. Though he managed to find political asylum in Mexico, he survived multiple assassination attempts over the years and a raid on his compound. 

However, on August 20, 1940, Trotsky’s luck ran out. A man who called himself Jacques Mornard had become friends with Trotsky and his armed guards. They exchanged sympathetic political views and chatted about trivial matters, but Mornard was actually Ramón Mercader, a Soviet agent. 

After drinking tea with Trotsky, Mercader found his chance. He used an ice axe intended for mountaineering to hack a hole into Trotsky’s skull. But the revolutionary wouldn’t die without a fight. He apparently grappled with Mercader, shouted for help, and even spat in his face and bit his hand during their altercation. Mercader was beaten by Trotsky’s guards and taken to prison. 

Trotsky was removed from the scene of the crime and operated on, but he died some 25 hours after the attack. Mercader (as "Mornard") was swiftly arrested and tried, claiming he had murdered Trotsky because he would not allow "Mornard" to marry a woman he loved. He served 20 years in prison under his assumed identity, though a secret counterintelligence project finally revealed his real name. While the Soviet Union denied any involvement in the murder of Trotsky, Mercader moved to Russia after his release and was eventually given an award for being a “Hero of the Soviet Union.” And as for Trotsky, the leader who fell from national hero to axed-down exile? He was buried in his own backyard.

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iStock // Ekaterina Minaeva
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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Scientists Think They Know How Whales Got So Big
May 24, 2017
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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]