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Wikimedia Commons

8 Important Daguerreotype Photos

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Wikimedia Commons

On this date in 1839, the French government released Louis Daguerre’s photographic process to the world—for free. The inventor began developing the process with partner Nicéphore Niépce in the early 1830s; it involved securing a thin, silver-plated copper sheet within a camera obscura and exposing the plate to the fumes from iodine crystals, which created a layer of light-sensitive silver iodide. When the photographer removed the camera's cover, the plate was exposed to light. In a darkroom, the plate would be developed with mercury fumes and fixed in a salt solution, creating a daguerreotype (Niépce died in 1833, so the process was named after Daguerre).

This process would be soon used around the world (except in England, where those who wanted to make daguerreotypes had to pay a hefty licensing fee; William Henry Fox Talbot, who created his photography process, called calotype, and patented it in 1841, would also sell licenses to use his method). Eventually, the daguerreotype process was replaced by the wet collodion process, but many photos—of political figures, of regular workers, of buildings and landmarks, of celestial bodies—would be frozen in time using Daguerre's method. Here are a few of them. 

1. L’Atelier de l'artiste

The still life of plaster casts on a window ledge above, taken by Daguerre in 1837, is purportedly the first surviving image taken using his process.

2. Boulevard du Temple, Paris

Wikimedia Commons

Daguerre took this photo, which is believed to be the earliest to show a living person, in 1838. Because of the long exposure time (10 minutes or more), no moving traffic was captured. But two men—a shoe shiner and his customer—were still enough to leave a trace.

3. Robert Cornelius

Library of Congress

This self-portrait of photographer Robert Cornelius is believed to be the first daguerreotype taken in North America

4. The Moon


John William Draper took the first daguerreotype of the moon in 1839 or 1840 from a rooftop in New York. His first attempt was not as successful.

5. Abraham Lincoln Portrait

Library of Congress

The earliest known photograph of America’s sixteenth president was a daguerreotype, taken when Lincoln was a 37 year old lawyer and Congressman-elect living in Springfield, Illinois.

6. The First News Photo

Getty Images

This French daguerreotype of an arrest in 1847 might be the first-ever news photograph.

7. Solar Eclipse Sequence

The Metropolitan Museum of Art

William and Frederick Langenheim weren’t the first photographers to capture a solar eclipse—that honor goes to a Russian photographer named Berkowski, who made the first photograph of a solar eclipse in 1851—but they did snap this eclipse, the first visible in North America since the invention of photography, on May 26, 1854. (The reason that the Moon travels from left to right in this eclipse, instead of from right to left, as it does in the Northern Hemisphere? All uncorrected daguerreotypes are reversed, as though looking in a mirror.) There was an eighth image, but as the Metropolitan Museum of Art points out, “In order to produce any kind of image at all, the Langenheims were forced to use the smallest cameras available, since smaller cameras require proportionally less light and there was virtually no available light when the disk of the new moon eclipsed the largest part of the sun. The missing eighth image was probably made on the smaller plate size and showed nothing at all—a total eclipse.”

8. Joseph Jenkins Roberts

The first and seventh president of Liberia, Joseph Jenkins Roberts, who emigrated there from Virginia in 1829. He was photographed in 1851 by Augustus Washington, an African American daguerreotypist who also emigrated to the country in 1853.

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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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200 Health Experts Call for Ban on Two Antibacterial Chemicals
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In September 2016, the U.S. Food and Drug Administration (FDA) issued a ban on antibacterial soap and body wash. But a large collective of scientists and medical professionals says the agency should have done more to stop the spread of harmful chemicals into our bodies and environment, most notably the antimicrobials triclosan and triclocarban. They published their recommendations in the journal Environmental Health Perspectives.

The 2016 report from the FDA concluded that 19 of the most commonly used antimicrobial ingredients are no more effective than ordinary soap and water, and forbade their use in soap and body wash.

"Customers may think added antimicrobials are a way to reduce infections, but in most products there is no evidence that they do," Ted Schettler, science director of the Science and Environmental Health Network, said in a statement.

Studies have shown that these chemicals may actually do more harm than good. They don't keep us from getting sick, but they can contribute to the development of antibiotic-resistant bacteria, also known as superbugs. Triclosan and triclocarban can also damage our hormones and immune systems.

And while they may no longer be appearing on our bathroom sinks or shower shelves, they're still all around us. They've leached into the environment from years of use. They're also still being added to a staggering array of consumer products, as companies create "antibacterial" clothing, toys, yoga mats, paint, food storage containers, electronics, doorknobs, and countertops.

The authors of the new consensus statement say it's time for that to stop.

"We must develop better alternatives and prevent unneeded exposures to antimicrobial chemicals," Rolf Haden of the University of Arizona said in the statement. Haden researches where mass-produced chemicals wind up in the environment.

The statement notes that many manufacturers have simply replaced the banned chemicals with others. "I was happy that the FDA finally acted to remove these chemicals from soaps," said Arlene Blum, executive director of the Green Science Policy Institute. "But I was dismayed to discover at my local drugstore that most products now contain substitutes that may be worse."

Blum, Haden, Schettler, and their colleagues "urge scientists, governments, chemical and product manufacturers, purchasing organizations, retailers, and consumers" to avoid antimicrobial chemicals outside of medical settings. "Where antimicrobials are necessary," they write, we should "use safer alternatives that are not persistent and pose no risk to humans or ecosystems."

They recommend that manufacturers label any products containing antimicrobial chemicals so that consumers can avoid them, and they call for further research into the impacts of these compounds on us and our planet.