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Voyager 1 Has Left the Solar System!

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Today, it was announced that Voyager 1 has left the solar system for interstellar space.

It’s not the first time the announcement has been made.

In October 2012, it was thought the intrepid probe, first launched in September 1977, had blasted out of the heliosheath and left the solar system—until a couple of months later, when particles weren’t quite acting as scientists thought they should in a region that came to be called the “magnetic highway”—the outer boundary of the heliosphere, where the sun’s magnetic particles and those from interstellar space mingle, not unlike a two-lane highway.

Scientists had thought two things would happen when Voyager officially left the solar system: That the solar winds would fade to nothing (which happened), and that the magnetic fields of the region would change direction marking the end of the sun’s influence. That one didn’t happen.

In recent months some scientists have been reassessing the data and saying “Yes, it might have left the solar system after all.” Now, NASA has confirmed that.

The whole debate was enough of a headache to get a nice ribbing from former JPL employee turned XKCD cartoonist Randall Munroe.

The Future of Interstellar Space Travel

Voyager 1 is now the first craft to officially leave the solar system, pacing along at 38,610 miles per hour. Others are set to follow.

Voyager 1's sister craft, Voyager 2, is not yet beyond the solar system, but is just a few years behind, traveling at a more sluggish crawl of around 35,000 MPH.

Two other probes, Pioneer 10 and 11, will also leave the solar system someday. Pioneer 10 was reported to have left by the New York Times in 1983except it was just past the orbit of Neptune at the time. Pioneer 11 accomplished this feat in 1990. But as the Voyagers have revealed, that is far, far shy of the end of the solar system.

Currently, Voyager 1 is more than 125 times the distance (called an AU, or astronomical unit) from the Earth to the Sun. Pioneer 10 is far behind that, projected at 109 AU in 2012. Communication was lost in 2003. Voyager 2 is still active, and is approximately 103 AU out. Pioneer 11, which NASA lost contact with in 1995, is estimated to be at 86 AU as of 2012.

We’d of course be remiss not to mention New Horizons, the craft currently on a trajectory for Pluto, which it will swoop by in 2015 before continuing on to the outer solar system. Thus far, it’s only about 27 AU out from the sun. It is expected to leave the solar system in 2029. A booster rocket of the craft is also on a path set to exit the solar system.

Little Green Men

With some push from Carl Sagan, both Voyager probes were given a “Golden Record,” a phonograph of words and images meant to tell aliens of existence here on earth, should the probes be found. Classical music melds with sounds of nature and a series of hellos in various languages on the disc.

Included in the music selections? “Johnny B. Goode” by Chuck Berry.

The Pioneers contain simple plaques, showing two naked humans, the position of the solar system in relation to a group of stars, and the location of the Earth within the solar system. (Prior to Pluto’s demotion, of course.)

Speaking of Pluto, New Horizons doesn’t have an equivalent to either on board. There are a few objects on board, though, which might pique the interest of the discoverers, even if they’ll have no way to tell what they are. Included is a CD with the names of 400,000 persons, as well as the ashes of Clyde Tombaugh, the astronomer who first discovered Pluto in 1930. A Florida state quarter and a scrap of SpaceShipOne are among the few other personal effects on the craft.

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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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Nick Briggs/Comic Relief
What Happened to Jamie and Aurelia From Love Actually?
May 26, 2017
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Nick Briggs/Comic Relief

Fans of the romantic-comedy Love Actually recently got a bonus reunion in the form of Red Nose Day Actually, a short charity special that gave audiences a peek at where their favorite characters ended up almost 15 years later.

One of the most improbable pairings from the original film was between Jamie (Colin Firth) and Aurelia (Lúcia Moniz), who fell in love despite almost no shared vocabulary. Jamie is English, and Aurelia is Portuguese, and they know just enough of each other’s native tongues for Jamie to propose and Aurelia to accept.

A decade and a half on, they have both improved their knowledge of each other’s languages—if not perfectly, in Jamie’s case. But apparently, their love is much stronger than his grasp on Portuguese grammar, because they’ve got three bilingual kids and another on the way. (And still enjoy having important romantic moments in the car.)

In 2015, Love Actually script editor Emma Freud revealed via Twitter what happened between Karen and Harry (Emma Thompson and Alan Rickman, who passed away last year). Most of the other couples get happy endings in the short—even if Hugh Grant's character hasn't gotten any better at dancing.

[h/t TV Guide]