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What’s the best design for splash-free urinal? Physics now has the answer



Enlarge / Can you spot the urinal design with the optimal splash-reducing angle? It’s the one second from right.

Mia Shi/University of Waterloo

Scientists at the University of Waterloo have determined the optimal design for a splash-free urinal: a tall, slender porcelain structure with curves reminiscent of a nautilus shell, playfully dubbed the “Nauti-loo.” That’s good news for men tired of having urine splash onto their pants and shoes—and for the poor souls who have to regularly clean up all the splatter. Bonus: It’s quite an aesthetically appealing design, giving this workhorse of the public restroom a touch of class.

“The idea originated exactly where you think it did,” Waterloo’s Zhao Pan told New Scientist. “I think most of us have been a little inattentive at our post and looked down to find we were wearing speckled pants. Nobody likes having pee everywhere, so why not just create a urinal where splatter is extremely unlikely?” His graduate student, Kaveeshan Thurairajah, presented the results of this research during last week’s American Physical Society (APS) meeting on fluid dynamics in Indianapolis.

It’s not the first time scientists have attempted to address this issue. Pan is a former graduate student of Tadd Truscott, a mechanical engineer who founded the so-called “Splash Lab” at Utah State University. In 2013, the Splash Lab (then at Brigham Young University) offered a few handy tips on how men could avoid staining their khaki pants with urine splashback while relieving themselves in restrooms. “Sitting on the toilet is the best technique, since there’s less distance for the pee to cover on its journey to the bowl,” I wrote previously at Gizmodo. “If you opt for the classic standing technique, the scientists advised standing as close to the urinal as possible, and trying to direct the stream at a downward angle toward the back of the urinal.”

For those who lack optimal anti-splash technique, another of Truscott’s graduate students, Randy Hurd, presented an optimal design for a splash-free urinal insert at the 2015 APS fluid dynamics meeting. There are three basic types of inserts. One employs absorbent cloth to keep splashing to a minimum; another uses a honeycomb structure—a raised layer (held up by little pillars) with holes—so urine droplets pass through but splash doesn’t come out; and a third type featuring an array of pillars. However, absorbent fabrics can’t absorb liquid quickly enough and soon become saturated, while the honeycomb and arrayed pillar structures don’t prevent urine pools from gradually forming.

In 2013, the Splash Lab demonstrated that reduced urine splash could be achieved by aiming at a vertical surface, moving closer to the urinal, and by decreasing the impact angle.

Hurd and Truscott’s insert design drew inspiration from a type of super-absorbent moss (Syntrichia caninervis) that thrives in very dry climates and thus is very good at collecting and storing as much water as possible. And they found that the manmade material called “VantaBlack” mimicked the moss’ absorbent properties. They copied that material’s structure for their urinal insert and found it successfully blocked droplets of pee from escaping—effectively acting as a “urinal black hole.”

Nor have the ladies been left out of this scientific (ahem) pissing contest. Women, too, suffer from urine spillage, most notably when required to pee into a cup for medical testing purposes. In 2018, the Splash Lab conducted a series of experiments involving a model of an anatomically correct female urethra. (They used a soft polymer to model the labia.) The results inspired the (patented) design of the “Orchid,” a funnel-shaped attachment for urine cups that reduces spillage. The research could lead to devices that allow women to pee standing up, which would be a boon to women in the military or female academics working in the field.

According to Pan, the key to optimal splash-free urinal design is the angle at which the pee stream strikes the porcelain surface; get a small enough angle, and there won’t be any splashback. Instead, you get a smooth flow across the surface, preventing droplets from flying out. (And yes, there is a critical threshold at which the urine stream switches from splashing to flowing smoothly, because phase transitions are everywhere—even in our public restrooms.) It turns out that dogs have already figured out the optimal angle as they lift their legs to pee, and when Pan et al. modeled this on a computer, they pegged the optimal angle for humans at 30 degrees.

Marcel Duchamp's "La Fontaine," photographed by Alfred Stieglitz at the 291 art gallery following the 1917 Society of Independent Artists exhibit.
Enlarge / Marcel Duchamp’s “La Fontaine,” photographed by Alfred Stieglitz at the 291 art gallery following the 1917 Society of Independent Artists exhibit.

Pan and his team also conducted a series of experiments with dyed fluids sprayed in jets of varying speeds into a range of faux-urinal designs (see top photo) made of dense, epoxy-covered foam—including the standard commercial shape and a urinal similar to the one Marcel Duchamp used in his famous (and controversial) 1917 art installation “La Fontaine.” All produced varying degrees of splashback, which the scientists wiped up with paper towels. They weighed the wet towels and compared that to how much the paper towels weighed when dry to quantify the amount of splash. The more the wet towels weighed, the bigger the splashback.

The next step was to figure out a design that would offer that optimal urine stream angle for men across a wide range of heights. Instead of the usual shallow box shaped like a rectangle, they landed on the curved structure of the nautilus shell. They repeated the simulated urine stream experiments with the prototypes, et voila! They didn’t observe a single droplet splashing back. By comparison, the other urinal designs produced as much as 50 times more splashback. There was one round design with an opening shaped like a triangle that performed even better than the Nauti-loo in the experiments, but Pan et al. rejected it because it wouldn’t work across a wide range of heights.

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Lost and found: Codebreakers decipher 50+ letters of Mary, Queen of Scots



Enlarge / Sample ciphertext (F38) found in the archives of the Bibliothèque Nationale de France, now attributed to Mary, Queen of Scots.

Bibliothèque nationale de France

An international team of code-breakers has successfully cracked the cipher of over 50 mysterious letters unearthed in French archives. The team discovered that the letters had been written by Mary, Queen of Scots, to trusted allies during her imprisonment in England by Queen Elizabeth I (her cousin)—and most were previously unknown to historians. The team described in a new paper published in the journal Cryptologia how they broke Mary’s cipher, then decoded and translated several of the letters. The publication coincides with the anniversary of Mary’s execution on February 8, 1587.

“This is a truly exciting discovery,” said co-author George Lasry, a computer scientist and cryptographer in Israel. “Mary, Queen of Scots, has left an extensive corpus of letters held in various archives. There was prior evidence, however, that other letters from Mary Stuart were missing from those collections, such as those referenced in other sources but not found elsewhere. The letters we have deciphered are most likely part of this lost secret correspondence.” Lasry is part of the multi-disciplinary DECRYPT Project devoted to mapping, digitizing, transcribing, and deciphering historical ciphers.

Mary sought to protect her most private letters from being intercepted and read by hostile parties. For instance, she engaged in what’s known as “letter-locking,” a common practice at the time to protect private letters from prying eyes. As we’ve reported previously, Jana Dambrogio, a conservator at MIT Libraries, coined the term “letter-locking” after discovering such letters while a fellow at the Vatican Secret Archives in 2000.

Those “locked” Vatican letters dated back to the 15th and 16th centuries, and they featured strange slits and corners that had been sliced off. Dambrogio realized that the letters had originally been folded in an ingenious manner, essentially “locked” by inserting a slice of the paper into a slit, then sealing it with wax. It would not have been possible to open the letter without ripping that slice of paper—providing evidence that the letter had been tampered with.

Portrait of Mary Stuart c. 1558–1560 at about 17 years old, painted by François Clouet.
Enlarge / Portrait of Mary Stuart c. 1558–1560 at about 17 years old, painted by François Clouet.

Public domain

Queen Elizabeth I, Catherine de Medici, Machiavelli, Galileo Galilei, John Donne, and Marie Antoinette are among the famous personages known to have employed letter-locking for their correspondence. There are hundreds of letter-locking techniques like “butterfly locks,” a simple triangular fold-and-tuck, and an ingenious method known as the “dagger-trap,” which incorporates a booby-trap disguised as another, simpler type of letter lock. Mary, Queen of Scots, used an intricate spiral letter-lock for her final letter (to King Henri III of France) on the eve of her execution for treason in February 1587. A 1574 letter from Mary also used a variant of the spiral lock.

Mary was well-trained in the art of cipher by her mother, Marie de Guise, from a very young age. The substantial collection of her letters that are housed in various archives contains tantalizing references to other missing letters. John Bossy, author of Under the Molehill: An Elizabethan Spy Story (2002), suggested that these missing letters might have been written in cipher to Mary’s extensive network of associates and allies—a network that was fatally compromised around mid-1583 by Sir Francis Walsingham (Elizabeth I’s spymaster), eventually leading to Mary’s trial and execution for treason. Like many before him, Bossy assumed those letters had been lost.

Enter Lasry and his fellow code-breaking enthusiasts: physicist and patents expert Satoshi Tomokiyo and pianist and music professor Norbert Biermann. As part of DECRYPT, they were scouring various archives for documents encrypted with ciphers, particularly documents that had not yet been attributed. They stumbled upon several collections at the Bibliothèque Nationale de France’s online archives, identifying 57 documents fully written in cipher. Other items in the collection dated from the 1520s and 1530s and were primarily concerned with “Italian affairs.” None of the text in the letters was written in clear language, so it wasn’t possible to determine who wrote them without first deciphering them.

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As Antarctic fieldwork ends, a sexual harassment reckoning looms



Enlarge / Personal tents for staff at the Shackleton Glacier science camp, situated on the Shackleton Glacier in the Transantarctic mountains of Antarctica.

In September 2022, two months before Ph.D. student Megan Kerr was scheduled to board a military plane bound for the Antarctic ice sheet, she found herself in a conference room on Oregon State University’s campus, waiting to ask a question that had been nagging her for weeks. She sat intently through a presentation from the National Science Foundation Office of Polar Programs. Then, she raised her hand. The room full of graduate students turned in their chairs.

“This NSF report about all the sexual harassment that’s going on in the field,” she said. “What is the NSF going to be doing in the short term, also long term, about that?” Because “a lot of us are going into the field in like, two months.”

These students and about a hundred other researchers from roughly a dozen institutions had gathered at Oregon State University to kick off COLDEX, a 5-year, $25 million-dollar paleoclimatology project tasked by the NSF, the federal science agency, to find and drill a core of Earth’s oldest ice in Antarctica.

The report Kerr mentioned was the 273-page elephant in the room—a document the NSF released in late August detailing a decades-long history of pervasive sexual harassment and assault at Antarctic research stations. Almost three-quarters of women surveyed agreed that harassment was a problem, describing it as a “fact of life” on the continent. And 95 percent of women interviewed in focus groups knew someone who had experienced assault or harassment within the Antarctic program. To outsiders, the graphic details and matter-of-fact descriptions were shocking. But in the polar science community, the reaction was different.

When the report came out, “No one was surprised, other than the grad students,” Kerr said. She spoke with her principal investigators and supervisors, “and they were like, ‘Yeah, it’s been an issue for a long time.’ Okay, why is this the first time I’m hearing about it?”

Since middle school, Kerr wanted to go to Antarctica. This most recent field season, which typically takes place over the Austral summer, from mid-October to mid-February, she had finally been chosen as part of an eight-person COLDEX team to survey the ice sheet at Antarctica’s remote South Pole. She was one of two graduate students, and the only woman, on her team.

“It sucked because I was so excited for it, you know?” Kerr said. “This is a thing I wanted for years and years. And finally I got to do it, I’m getting to do it, and then I hear that oh, actually, it’s a terrible place to work if you’re a woman.”

COLDEX leadership thinks their initiative, with its unprecedented funding, unusually long timescale, and built-in commitment to diversify the polar sciences, could bring some change. But Kerr and her fellow graduate students worry the NSF response to a systemic, deeply entrenched culture problem has been surface level. They are also left wondering what the field’s path forward looks like.

Erin Pettit is an experienced polar researcher and COLDEX’s director of diversity, equity, and inclusion. Originally, her role was to guide the center in its mandate to recruit a more diverse team of researchers. But now, she’s also responsible for COLDEX’s response to the bombshell NSF report. To her, those goals are closely linked.

“Our biggest challenge actually stems from the fact that polar science started from white, male, Northern European explorations,” said Pettit. “And it is still very white and mostly male.”

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Here’s why Europe is abandoning plans to fly aboard China’s space station



Enlarge / US Vice President Kamala Harris shakes hands with Josef Aschbacher, director general of the European Space Agency, right, during a tour of Artemis II and Artemis III mission hardware at Kennedy Space Center in Cape Canaveral, Florida, in 2022.

Alex Perez/Sipa/Bloomberg via Getty Images

Nearly six years ago the European Space Agency surprised its longtime spaceflight partners at NASA, as well as diplomatic officials at the White House, with an announcement that some of its astronauts were training alongside Chinese astronauts. The goal was to send European astronauts to China’s Tiangong space station by 2022.

“We were welcomed as colleagues and friends by the ‘taikonauts’ and the instructors,” said European astronaut Samantha Cristoforetti at the time. “Language and cultural differences are obviously a challenge, but also adds value, as we are all focused on the common goal of space exploration.”

European astronauts did not fly to the Chinese space station in 2022, however, even though China completed its construction before the end of the year. In fact, Europeans are now unlikely ever to do so, even as the Tiangong facility flies for another decade, or longer, in low-Earth orbit.

During his annual press briefing in late January, Josef Aschbacher, director general of the European Space Agency, said his focus remains on the International Space Station Partnership with NASA, Russia, Canada, and Japan. “For the moment we have neither the budgetary nor the political, let’s say, green light or intention to engage in a second space station—that is participating on the Chinese space station,” Aschbacher said.

So what changed?

Relations with US weaken

According to multiple sources who spoke with Ars on background, Aschbacher was accurate when he characterized the budget situation. ESA’s funding is less than one-third that of NASA. During its most recent budget cycle, although the space agency received an increase from member nations, it did not receive nearly all of the money it asked for. There is, accordingly, no funding to barter with China for access to Tiangong.

However, the more significant reason is probably a political one. The Americans really were blindsided by Europe’s announcement of the Chinese partnership in 2017. It came as the United States was trying to determine its own path forward with regard to the space station’s lifetime and follow-on projects. At the time, the notion that the station should fly until 2028 or even 2030 was not a universal one among US policymakers.

The Trump administration muddied these waters with a 2018 budget proposal to end the International Space Station in 2026, in order to free up funding for what would become the Artemis Moon program. This effort was quickly beaten back by the US Congress, but European officials could not help but wonder where their astronauts would go in the latter half of the 2020s if the International Space Station was gone.

Some European officials, too, were uncomfortable with the Trump administration’s talk of militarizing space. For example, in mid-2018, a key European space official, then-ArianeGroup chair Alan Charmeau, talked of how the continent must resist US efforts at space dominance. “Europe is not going to say, ‘I want to dominate the space world,'” Charmeau said. “Europe is looking for other things. Europe wants access to space. Europe wants to have their own infrastructure in space, with Galileo and Copernicus. We seek cooperation.”

At the time, this cooperation included working with China on an array of space initiatives, including astronaut training. From a political standpoint, ESA officials knew this was unwelcome by their NASA counterparts. However, it afforded them a measure of leverage with the US space agency.

Attitudes change

In the last few years, however, geopolitics and space policy have changed. Initially, almost everyone involved in space policy harbored doubts about the stability of the Trump administration’s Artemis program to return to the Moon. However, Artemis has since crystallized into a real and well-funded program. In November, when the Artemis I mission launched from Florida, European space officials proudly watched as Orion’s European-made service module propelled the vehicle out to the Moon and back to Earth.

Generally, European space officials like the Artemis program and are seeking areas for greater involvement. This is drawing them closer to NASA.

Then came Russia’s invasion of Ukraine a year ago. This has badly shaken the continent, and Russia’s war against Ukraine has strengthened ties between Europe and the United States across a number of fronts, including space.

ESA astronauts Samantha Cristoforetti and Matthias Maurer joined Chinese colleagues in Yantai, China, to take part in sea survival training, in August 2017.
Enlarge / ESA astronauts Samantha Cristoforetti and Matthias Maurer joined Chinese colleagues in Yantai, China, to take part in sea survival training, in August 2017.


Conversely, the war has driven China and Russia closer in some respects. Over the last 18 months China and Russia have been drawing up plans for an International Lunar Research Station. They intend to establish a base of operations at the Lunar South Pole, and this is correctly viewed as a Chinese-Russian alternative to the Artemis program.

Europe has been watching, and China’s passive support of Russia amid this aggression has pushed its capitals to revisit their partnerships with China. For spaceflight, this has fortified Europe’s view that it has a more stable future working with NASA and other like-minded partners in low-Earth orbit, as well as deep space. For this reason, publicly stepping back from plans to send European astronauts to China’s space station, at this time, makes sense.

Aschbacher and Europe’s space officials still want some autonomy from the United States on matters such as space launch, of course. But they understand that to realize larger programs of human spaceflight they need to pick a side. And now they have.

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