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4 Women Who Rocked Physics

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When asked to name women who have significantly contributed to science, most people shrug and say, "Marie Curie?" In fact, women have added to our scientific repertoire capabilities no less than nuclear fission and modern day alchemy, among many other discoveries.

1. Lise Meitner

Lise Meitner (1878-1968) was a quiet, self-effacing Austrian-Jewish woman who has come to be known "the mother of the atomic bomb." After studying under Boltzmann and Planck (yes, that Boltzmann and Planck), she became the acting director of the Kaiser-Wilhelm Institute of Chemistry in Berlin. It was there that, alongside partner Otto Hahn, she noted in an experiment that uranium-238 nuclei split into barium and krypton, along with several neutrons and a pocket of energy. Meitner was the first to describe and name the process-- "nuclear fission"-- and noted the potential for a chain reaction (Keanu Reeves not included). However, she was exiled from Germany shortly after the Anschluss, and so Hahn and two others published the research in 1938. For this, Hahn two other men won the 1944 Nobel Prize in Chemistry.

2. Chien-Shiung Wu

Wu.jpgChien-Shiung Wu (1912-1997) was born in China and earned her Ph.D. from UC-Berkeley in 1940. At this time, it was considered a dependable rule in matter behavior that identical particles would always act in a way that was consistent and symmetrical. However, upon observing the beta decay of cobalt-60, Wu noticed that the weak interactions between emitted beta particles caused them to strongly prefer to travel in a certain direction "“ roughly equivalent to watching air rush into a balloon of its own accord. With this research, Wu proved that nature is not always naturally symmetrical, upending a formerly watertight law. The Nobel Prize for Physics in 1957 was awarded to researchers of this discovery; Wu was not among their number.

3. Maria Goeppert-Mayer

mayer.jpgMaria Goeppert-Mayer (1906-1972) hailed from Germany and attended the University of Gottingen. After stints working with Born and Planck and teaching at Sarah Lawrence College, Goeppert-Mayer ended up in Chicago working at the Argonne National Laboratory. While there she worked with Edward Teller and Enrico Fermi, learning the ropes of nuclear physics as she went. It was at this time she developed a model of the atomic nucleus, which took the form of shells similar to the atomic shell model. She also discovered that there were certain "magic numbers" of nucleons for which the energy holding them together was less than the preceding number -- for example, it took significantly less energy to hold together 20 nucleons than it did 19 -- and she worked out the supporting mathematics. For this achievement, she won the Nobel Prize for physics in 1963.

4. Harriet Brooks

mcgill.jpgHarriet Brooks (1876-1933) was born in Canada, attended McGill University, and worked as a graduate student under Ernest Rutherford. Rutherford had noticed that radioactive thorium gave off a substance other than radioactive rays, and left it to Brooks to figure out what it was. Brooks identified the "emanation" from thorium as an element in gas form that was, strangely, not thorium. Brooks realized that this meant that one element could, with the right conditions, be used to produce a completely different element. It may sound uncool to discover that alchemy actually works roughly a millennium too late, but on the upside, nuclear transmutation is used today in tokamaks as well as fission power reactors.

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iStock // Ekaterina Minaeva
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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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Opening Ceremony
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These $425 Jeans Can Turn Into Jorts
May 19, 2017
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Opening Ceremony

Modular clothing used to consist of something simple, like a reversible jacket. Today, it’s a $425 pair of detachable jeans.

Apparel retailer Opening Ceremony recently debuted a pair of “2 in 1 Y/Project” trousers that look fairly peculiar. The legs are held to the crotch by a pair of loops, creating a disjointed C-3PO effect. Undo the loops and you can now remove the legs entirely, leaving a pair of jean shorts in their wake. The result goes from this:

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Opening Ceremony

To this:

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Opening Ceremony

The company also offers a slightly different cut with button tabs in black for $460. If these aren’t audacious enough for you, the Y/Project line includes jumpsuits with removable legs and garter-equipped jeans.

[h/t Mashable]

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