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7 Planets, as composed by Holst

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The English composer Gustav Holst completed his most famous work, The Planets, about 15 years before Pluto was discovered. The piece was inspired by astrology, not astronomy (though he wasn't eager to reveal his main influences because the most famous astrologer in Britain, Alan Leo, had been prosecuted under the Vagrancy Act of 1917, which declared all astrologers, palmists, clairvoyants and mediums "common thieves and vagabonds.")

By the time Pluto was discovered, Holst was so over the success of the piece, which seriously dwarfed the rest of his works, the composer decided against adding an 8th movement, refusing to write a Pluto.

As we know now, this turned out to be a good thing. The one and only 7-movement piece (there was never an Earth movement) is about 50 minutes long when played in its entirety. I'll recommend some of the better recordings at the end of the post, but let's first look at each planet.

1. Mars, the Bringer of War

2. Venus, the Bringer of Peace

Venus.jpgThe second movement, Venus, is much quieter. Here Venus is not the Roman Goddess of fruitfulness, instead Holst based his inspiration on the work of Leo, who once wrote: "Venus creates orderly harmonic motion .... everywhere it produces order out of disorder, harmony out of discord." Listen for the beautifully peaceful opening French horn solo, before the rest of the woodwinds enter.

3. Mercury, the Winged Messenger

mercury.jpgLeo used to call Mercury the "thinker." Also, in his book How to Judge a Nativity, he writes that the planet is "the Winged Messenger," which is what Holst went with for his subtitle. Leo also describes the planet in a way that aptly describes the orchestration of the movement. "Mercury ... represents the silver thread of memory, upon which are strung the beads which represent the personalities of its earth lives". Listen for the "silver thread" as depicted by the use of the glockenspiel and celesta toward the end of the excerpt I've chosen.

4. Jupiter, the Bringer of Jollity

jupiter.jpgThe opening of this upbeat movement borrows again from Stravinsky, this time another ballet, Petrushka. Leo described Jupiter as "the Uplifter" signifying "happiness and abundance" and "expansion." Listen for that in the excerpt I've selected, which comes right at the beginning of the movement.

5. Saturn, the Bringer of Old Age

saturn.jpgThe great majority of this movement is quiet, slightly lugubrious, and slow. It's meant to portray the slow onslaught of old age. But about five minutes into the 10-minute movement, the brass start to rise up out of the muck in a minute-long crescendo that seems to suggest a rejection of sorts. It's as if the mighty brass section is revolting, refusing to grow old with the rest of the instruments. Again, you'll hear some passages that Williams borrowed in one of the Star Wars flicks. It's all quite dramatic.

6. Uranus, the Magician

uranus1.jpgFor some reason, classical composers usually associate magic with jazzy, syncopated rhythms. Berlioz' "Witches Sabbath," the final movement in his Symphonie Fantastique, and Dukas' symphonic poem, The Sorcerer's Apprentice, come to mind, and were probably in Holst's mind when he sat down to write Uranus. The movement is about 6 minutes long. I've selected an excerpt that, because of the way Holst orchestrated it with all the tambourine, has always reminded me of Rimsky Korsakov's Scheherazade. See what you think.

7. Neptune, the Mystic

neptune.jpgThe eight-minute long last movement is perhaps the most celestial of all. As usual, Holst's depiction of Neptune doesn't match the traditional view of the storm-bringing god of the sea. But unlike the others, so influenced by Leo's writing, Neptune seems more about the planet orbiting slowly on the edge of outer darkness, at least to me. The music is quiet and mysterious. Holst uses a choir toward the end that's reminiscent of Debussy and Ravel, only this all-female choir fades out into space, nothingness - perhaps the first musical fade-out in history. The selection I've chosen is before the choir comes in, pretty much in the middle of the movement.

All the excerpts you hear in this post come from my favorite recording of this work, a Decca issue made by Charles Dutoit and the Montreal Symphony Orchestra. But there are others I own or have heard that can also be recommended. Herbert von Karajan's later version (the digital one) with the Berlin Philharmonic is great, as is John Eliot Gardiner's recording with the Philharmonia Orchestra. People tell me that James Levine's version with the Chicago Symphony Orchestra is very lush and romantic, very on the sleeve, for those who prefer that kind of an approach. I heard a bit of it on iTunes and agreed. Go check them all out and pick the one you like best because this is a must own for any music lover.

Check out past On Music posts here >>

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iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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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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Cs California, Wikimedia Commons // CC BY-SA 3.0
How Experts Say We Should Stop a 'Zombie' Infection: Kill It With Fire
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Cs California, Wikimedia Commons // CC BY-SA 3.0

Scientists are known for being pretty cautious people. But sometimes, even the most careful of us need to burn some things to the ground. Immunologists have proposed a plan to burn large swaths of parkland in an attempt to wipe out disease, as The New York Times reports. They described the problem in the journal Microbiology and Molecular Biology Reviews.

Chronic wasting disease (CWD) is a gruesome infection that’s been destroying deer and elk herds across North America. Like bovine spongiform encephalopathy (BSE, better known as mad cow disease) and Creutzfeldt-Jakob disease, CWD is caused by damaged, contagious little proteins called prions. Although it's been half a century since CWD was first discovered, scientists are still scratching their heads about how it works, how it spreads, and if, like BSE, it could someday infect humans.

Paper co-author Mark Zabel, of the Prion Research Center at Colorado State University, says animals with CWD fade away slowly at first, losing weight and starting to act kind of spacey. But "they’re not hard to pick out at the end stage," he told The New York Times. "They have a vacant stare, they have a stumbling gait, their heads are drooping, their ears are down, you can see thick saliva dripping from their mouths. It’s like a true zombie disease."

CWD has already been spotted in 24 U.S. states. Some herds are already 50 percent infected, and that number is only growing.

Prion illnesses often travel from one infected individual to another, but CWD’s expansion was so rapid that scientists began to suspect it had more than one way of finding new animals to attack.

Sure enough, it did. As it turns out, the CWD prion doesn’t go down with its host-animal ship. Infected animals shed the prion in their urine, feces, and drool. Long after the sick deer has died, others can still contract CWD from the leaves they eat and the grass in which they stand.

As if that’s not bad enough, CWD has another trick up its sleeve: spontaneous generation. That is, it doesn’t take much damage to twist a healthy prion into a zombifying pathogen. The illness just pops up.

There are some treatments, including immersing infected tissue in an ozone bath. But that won't help when the problem is literally smeared across the landscape. "You cannot treat half of the continental United States with ozone," Zabel said.

And so, to combat this many-pronged assault on our wildlife, Zabel and his colleagues are getting aggressive. They recommend a controlled burn of infected areas of national parks in Colorado and Arkansas—a pilot study to determine if fire will be enough.

"If you eliminate the plants that have prions on the surface, that would be a huge step forward," he said. "I really don’t think it’s that crazy."

[h/t The New York Times]