Scientists have taken a major step toward the ambitious global goal of “redefining the second” by the end of this decade. A study published this week details how researchers from six different countries simultaneously compared measurements from 10 optical clocks—an advanced form of timekeeping that is up to 100 times more accurate than the best cesium clocks, which are currently used as the global standard.

The measurements amount to the largest coordinated comparison of optical clocks to date, and significantly reduced the uncertainty between measurements reported in previous studies. This also means that optical clocks are closer than ever to becoming the new standard for timekeeping, a shift that could have a massive ripple effect on everything from meteorology to our understanding of fundamental physics. 

Researchers say the findings support “the advance toward a redefinition of the second and the use of optical standards for international time scales.”

In a nutshell, optical clocks are incredibly accurate instruments that measure the frequency of atoms after they’ve been excited by lasers. The atoms are first cooled to near absolute zero, then lasers are used to detect their vibrations. Those vibrations are called frequency ratios. This precise frequency then corresponds to the “tick” of a second. Scientists believe this method yields far more accurate results than the cesium atomic clocks, which have been the global standard for the past five decades. For context, researchers say an optical clock would not gain or lose a second for billions of years. In fact, New Scientist estimates you could wait the current age of the universe four times over, and an optical clock would still be off by less than a minute. Compare that to a typical wristwatch, which can drift over just a few months.

Optical clocks are incredibly precise, but they are also highly complex. There are just around 100 of them in existence worldwide, largely because they are difficult to build, operate, and maintain—they are also susceptible to breakage. Comparing them against each other is notoriously challenging. Different clocks measure the frequencies of different types of atoms, each with its own unique frequency. This means the only way to establish a consistent, highly precise standard is to directly compare the clocks with one another. That’s where these most recent findings come in.

Researchers from Finland, France, Germany, Italy, the UK, and Japan collaborated on a European-led project called ROCIT to compare 10 different clocks. The measurements were conducted over a 45-day period in 2022. In the past, smaller-scale optical clock comparisons relied on satellite links to measure differences, but this study used both satellite links and fiber optic cables. That’s important because it allows for more accurate measurements.

“Comparing multiple clocks at the same time and using more than one type of link technology provides far more information than the mostly pairwise clock comparisons that have been carried out to date,” VTT MIKES meteorology research center senior scientist Thomas Lindvall said in a statement. 

Related: [Refining the clock’s second takes time—and lasers]

The fiber optic cables spanned thousands of miles across Europe, allowing researchers to connect the frequency outputs of the various clocks. They accounted for signal noise and other limitations of the instruments during the process. In total, the comparison produced 38 different frequency ratios measured simultaneously, four of them for the first time. The remaining ratios were measured with greater accuracy than ever before, according to the researchers.

“These measurements provide critical information about what work is still needed for optical clocks to achieve the precision and reliability required for use in international timekeeping,” Instituto Nazionale Di Ricerca Metrologica (INRiM) senior researcher Marco Pizzocaro said in a statement. “Our experiment also showed how optical clocks across Europe can be linked to measure frequency ratios with state-of-the-art precision.”

Although more comparisons are needed before optical clocks can officially become the global standard, researchers are optimistic about the future. The benefits go beyond just improved timekeeping. More precise measurements could help scientists test Albert Einstein’s theory of relativity with greater accuracy and offer new insights into the still-mysterious concept of dark matter.

At the same time, scientists are also making headway on entirely new “nuclear clocks” that might make opticals look like relics. Last year, the National Institute of Standards and Technology (NIST) said they were close to completing a nuclear clock prototype that focuses on vibrations, not from a single atom, but from a single nucleus. 

“Imagine a wristwatch that wouldn’t lose a second even if you left it running for billions of years,” NIST and JILA physicist Jun Ye said last year following news of the prototype. “While we’re not quite there yet, this research brings us closer to that level of precision.”

The post Scientists are redefining time itself, starting with the second appeared first on Popular Science.

Four weedy seadragon (Phyllopteryx taeniolatus) males are carrying eggs for the first time in a public aquarium. The Columbus Zoo and Aquarium in Ohio announced the achievement just in time for Father’s Day–and some have already hatched.

Weedy seadragons are bony seahorse relatives native to Australia’s coasts with small heads, long tails, and leaf-like limbs. They can reach 18 inches long, and blend in marvelously with seaweed, which has made it difficult for researchers to study them in the wild. Their unique reproductive process is also infamously difficult to nurture in captive breeding programs, so the sea creatures have remained enigmatic. Like their other seahorse cousins, weedy seadragon males carry fertilized eggs instead of the females. 

“In the world of aquatic animal care, this is a remarkably rare and meaningful milestone,” Megan Brown, director of Population Management Strategy for the Association of Zoos and Aquariums, said in a Columbus Zoo and Aquarium statement. “Weedy seadragons are among the most challenging marine species to breed, and observing multiple males brooding eggs within the same timeframe offers exciting new insight into their complex reproductive biology—something few facilities have accomplished.”

Part of the complexity comes from the weedy seadragons’ intricate mating ritual. It essentially involves a snout-to-snout dance in which a male and female mirror each other’s movements as they travel up and down a water column. The female transfers her eggs onto the male’s tail, where he fertilizes and carries them until they hatch six to eight weeks later. 

As of Monday June 9, 20 eggs have hatched at the Columbus Zoo and Aquarium. The organization’s animal care team is keeping a close eye on the inch-long hatchlings. A baby seahorse at this stage is called a fry and this crew is reportedly scarfing down around 9,000 baby mysis shrimp and 18,000 copepods (planktonic crustaceans) per week with a “voracious appetite.” The team will actively raise them for at least a year. 

[ Related: 8 animal fathers that take care of their eggs. ]

In 2024, the aquarium also had reason to celebrate when a single weedy seadragon hatched over 20 babies, the first ever weedy seadragons to hatch in their tanks. According to the organization, only a few North American institutions have achieved this.

Weedy seadragons are not the only species with highly engaged fathers. Male seahorses, emperor penguins, silverback gorillas, and arctic wolves are just some of the dads that deserve an extra special Father’s Day celebration. 

The post Weedy seadragons in the running for nature’s best dads appeared first on Popular Science.

June marks the beginning of baby skunk season, when skunk kits start following their mothers out of their dens. In less than 24 hours, the Raven Ridge Wildlife Center in Washington Boro, Pennsylvania admitted 27 kits into their care. In a Facebook post, the wildlife center in southeastern PA, described a “particularly heartbreaking case” in which a good Samaritan discovered baby skunks near an old shed. 

“A single baby skunk or several skunk kits found alone are always in need of rescue,” Tracie Young, a licensed wildlife rehabilitator at the Raven Ridge Wildlife Center, tells Popular Science. “Mother skunks are very protective of their kits and will never leave them out of her sight. The baby skunks have poor eyesight but a good sense of smell and that is how they locate and are able to stay with her, especially at night.” 

In other words, if a skunk kit is on its own, it’s not because it strayed too far and got lost. Sure enough, the man also found what he believed to be the dead mama skunk. He thus put the babies in a box and drove them to the wildlife center. The facility’s staff will care for the baby skunks for several months before setting them free, according to the post. 

Young says that they receive an average of 50 to 70 skunks kits during the busy baby season, and can admit over 20 adults throughout the year. Admitted skunks are typically suffering with issues spanning from rabies to soda cans stuck on their heads. 

The greatest threats to baby skunks include predators such as the great horned owls (skunks are apparently their favorite food), vehicle collisions, dog attacks, and even members of the public who “fall in love with this little innocent cute ball of fuzz and decide to keep it.” 

Unfortunately, in states like Pennsylvania, this human exposure requires authorities to euthanize the skunk and test it for rabies. Young thus emphasizes that if anyone spots one or more motherless skunk babies, they should always reach out to a licensed wildlife rehabilitation center that specializes in skunks. 

[ Related: What to do if you find a baby bird out of its nest. ]

Plus, life is pretty good at the Raven Ridge Wildlife Center (though the best place for a kit skunk is at its mother’s side). Young explains that skunks have individual body language and attitudes, similarly to cats. Since they have “poor eyesight and we never want to startle them, we actually sing to them,” she says, specifying that their song of choice is a modified version of the viral ‘Baby Shark.’

Baby skunk do do do do do do… 

The post Rescued baby skunks enjoy a good song appeared first on Popular Science.

Advocates for good cause eviction protections, which prevent landlords from evicting tenants without a valid reason, have long faced pushback from developers who claim such laws discourage new construction. However, a new report from the University of Minnesota’s Center for Urban and Regional Affairs (CURA) finds no evidence that good cause policies reduce building permits or housing development.

The study compared counties in states with recently enacted good cause laws — such as California, Oregon, and New Hampshire — to neighboring regions without these protections. After accounting for economic variables, the researchers concluded that good cause policies had no impact on new construction.

Despite this data, resistance persists. In Maryland, where legislation to allow localities to adopt good cause failed to pass this year, opponents have shifted their arguments. Instead of focusing on whether good cause alone hurts development, they now argue that a combination of tenant protections — including rent stabilization and vacancy control — deters investment.

State Senator Will Smith, who played a key role in stalling the Maryland bill, claimed that while good cause alone may not harm housing, its combination with other protections does. However, critics argue that this is an attempt to undermine other tenant safeguards like vacancy control by linking them to good cause efforts.

Meanwhile, in Connecticut and Rhode Island, tenant advocates are using the CURA research to support their campaigns, though with mixed results. In Connecticut, the research helps counter objections but hasn’t shifted the broader debate centered around property rights. In Rhode Island, however, the data has influenced legislative commissions reviewing housing laws.

Advocates emphasize that while public support for good cause laws may come from lived experiences of housing insecurity, policymakers are more swayed by industry claims and developer pressure — despite lacking evidence. The continued repetition of developer narratives in media and politics, even after being debunked, underscores the challenge tenant advocates face in shifting public policy.

• Good Cause Eviction
• Eviction
• Tenants Rights
• Tenant Protections
• Landlords
• Rent

1. Launch Finder on your Mac (or iTunes on Windows PCs.)


2. Connect your iPhone or iPad to your computer using a Lightning or USB-C cable.


3. Put your device into recovery mode. The method of doing this depends on your device, so check the list below these steps to find your model. Apple also provides more information on Recovery mode in this support article.
   
   
4. A dialog will pop up asking if you want to restore your device. Click Restore to wipe your device and install the latest public release of iOS or iPadOS.


5. Wait while the restore process completes.

• iPad models with Face ID: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Press and hold the Top button until your device begins to restart. Continue holding the Top button until your device goes into recovery mode.
  
• iPhone XS or later: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Then, press and hold the Side button until you see the recovery mode screen.

Bipedal, humanoid robots from companies like Boston Dynamics seemingly advance by the week, but they still can’t match their most audacious sci-fi inspirations. One of the major barriers they haven’t overcome is the ability to “feel” sensations like a human. Although researchers have tried various sensors to give robots a rudimentary sense of touch, these systems are often costly, inaccurate, and limited to detecting only one type of sensation at a time.

But that may be about to change. Researchers from the University of Cambridge and University College London have developed a new type of responsive “synthetic skin.” The skin is made from a single hydrogel that is capable of detecting touch, pressure, heat, cold, and damage in a way that more closely resembles human skin. 

The researchers were able to cast this gel into the mold of a hand and place it over a robot like a glove. By wearing the chunky flesh mitt, the robot can more accurately “feel” the world around it. Though still in the early stages, researchers say this type of synthetic skin could one day help robots work more effectively in factories, dangerous environments, or even assist in disaster relief efforts. The findings were published this week in the journal Science Robotics. 

Synthetic skin in robotics isn’t entirely new. Since as early as 2016, researchers have demonstrated the ability to use small sensors in robotic fingertips and hands to help them sense the shape and texture of certain objects. Until now though, that process would get quite complicated, quite quickly. A robotic hand capable of sensing both heat and pressure would require two different types of sensors—each designed to detect a specific sensation. These sensors can interfere with one another, causing what researchers call “cross talk.” Such mixed signals can also reduce the accuracy of perception and, in some cases, even damage the sensors. Adding more sensors to a small area like a robot hand also increases complexity, which raises the likelihood of errors.

“Having different sensors for different types of touch leads to materials that are complex to make,” lead author and Cambridge professor David Hardman said in a statement. “We wanted to develop a solution that can detect multiple types of touch at once, but in a single material.”

The researchers aimed to develop an alternative to the complicated multi-sensor approach by using a single material capable of detecting multiple types of stimuli. To do that, they used a soft, stretchable, and conductive gelatin-based hydrogel that can convert physical inputs, like heat and pressure, into electronic signals processed by a computer. According to the researchers, the gel itself is capable of detecting signals through 860,000 individual pathways embedded within the material. They conducted physical tests on the synthetic skin, exposing it to various types of stimuli at different levels to fine-tune its responsiveness. 

Related:[Lab-grown, self-healing human skin designed to cover robot faces]

That synthetic skin can also be melted down and reconfigured into new shapes. In this case, the researchers wanted to see if it would still function when molded into the shape of a human hand. The result was an odd-looking yellow-and-black hand resembling a battered construction glove. This glove was then placed over the robot’s hand. To test it, researchers pressed on it with a finger and lightly swabbed the surface. Even in this more realistic form, the skin was still able to differentiate between different levels of pressure.

From there, the researchers exposed the hand to a “heat blast,” partially melting it. They took the abuse a step further by using a scalpel to slice the hand open. Thanks to the synthetic skin, the glove was able to “feel” each different stimulus—all through a single, universal sensor. While it was still less responsive than human skin, it outperformed other approaches that rely on multiple sensors.

“We’re not quite at the level where the robotic skin is as good as human skin, but we think it’s better than anything else out there at the moment,” paper co-author and University College London researcher Thomas George Thuruthel said in a statement. “Our method is flexible and easier to build than traditional sensors, and we’re able to calibrate it using human touch for a range of tasks.”

The researchers say there’s a practical reason for all the poking, prodding, and burning their robot’s weathered hand. The tests demonstrate that, at least in theory, this synthetic skin could be melted down and molded to fit various parts of a robot’s body and still sense touch. A machine with this outer layer of sensing skin could then navigate its environment—whether in an automobile factory or on a construction site—and interact with the world in a way more similar to a human. That capability could become especially useful if humanoid robots, like those being developed by companies such as Figure and Tesla, are ever deployed to work alongside humans in real-world settings. If a robot is handing a car part to a human, it should probably know if it’s ripping hot.

Figure is already testing its humanoid robots in BMW’s South Carolina manufacturing facility. Amazon, meanwhile, is reportedly already training humanoid robots to carry and drop off packages to customers. 

An odd future where fleshy robots deliver your latest order of toilet paper, in other words, might not be all that far-fetched. 

The post Researchers create most human-like robot skin yet appeared first on Popular Science.

Very little in this life is truly random. A coin flip is influenced by the flipper’s force, its surrounding airflow, and gravity. Similar variables dictate rolling a pair of dice or shuffling a deck of cards, while even classical computing’s cryptographic algorithms are theoretically susceptible to outside influence or bias.

“True randomness is something that nothing in the universe can predict in advance,” explained Krister Shalm, a physicist at the National Institute of Standards and Technology (NIST).

So how does someone achieve true randomness? For that, you need to peer into the quantum realm. The task once required years of study and access to vast research facilities, but thanks to an ingenious new project from Shalm and his colleagues, now anyone can access a “factory for random numbers.” And it’s free to use.

Designed by NIST in collaboration with the University of Colorado Boulder, the Colorado University Randomness Beacon (CURBy) is a first-of-its-kind system that relies on headspinning quantum mechanics concepts to offer truly random number generation.

More specifically, CURBy’s foundation rests on a task known as the Bell test. Named after the famed physicist John Stewart Bell, the test measures pairs of entangled photons with properties that remain correlated even after separating across huge distances. While the outcome is always random when measuring a single particle, a pair’s properties are more correlated than classical physics dictates. This allows experts to verify the randomness at a quantum level.

Albert Einstein previously described this “quantum nonlocality” as “spooky action as a distance,” and he wasn’t a fan of the idea. Unfortunately for him, NIST proved its existence back in 2015. Three years later, they developed methodologies to use Bell tests in order to construct the world’s first true randomness generators.

These initial random results necessitated months of refinement and only ran for a few hours in total. Even then, the physicists and engineers only generated 512 bits of true randomness. Since then, researchers expanded and automated their experiment, thus offering random numbers whenever needed.

“We really wanted to take that experiment out of the lab and turn it into a useful public service,” said Shalm.

Their finalized protocol served up randomness 7,454 times over its first 40 days of existence. Researchers then recorded 7,434 cases of randomness—a success rate of 99.7 percent.

But how do you actually generate true randomness? For that, you need a system that relies on a bespoke nonlinear crystal to generate entangled photon pairs. The particles then speed away in an optical fiber to separate laboratories at opposite ends of a hallway at NIST. Once they reach the two labs, researchers measure their subsequent polarizations. This relay race is then repeated a headspinning 250,000 times per second.

All that data needs to be processed, so NIST sends off its millions of quantum coin flips to a specially designed computer program built by engineers at UC Boulder. The program then translates the measurements into 512 random bits of binary code that can then be parsed by anyone.

But utilizing CURBy is much simpler than the dizzying quantum computations required to generate true randomness. All a user needs to do is head to its website and key in the list of items you want shuffled. CURBy then will rearrange the entries based on any given day’s quantumly determined randomness. The outcome is decades in the making, and would have certainly given Einstein something to think about.

“I am at all events convinced that [the Creator] does not play dice,” he famously wrote to Max Born in 1926 regarding the concepts of quantum theory.

“If God does play dice with the universe, then you can turn that into the best random number generator that the universe allows,” Shalm said. 

The post Here’s how to generate a truly random number with quantum physics appeared first on Popular Science.

In a piece in the California Planning & Development Report, Josh Stephens makes the case that the decline of the Los Angeles film industry — “with 31% fewer filming days in 2024 compared to 2020” — is tied up with the city’s housing crisis.

"Fundamentally, entertainment and real estate must predict the future. Projects evolve on the order of years. They are capital-intensive, demanding up-front monies years before revenues come in, depending on the whims of consumers. Some projects appeal to urban aesthetes; others are family-friendly. Ultimately, audiences file into the theater or turn on the TV, inhabiting a fantasy for a little while. Residents and tenants move in, acting out their lives for months, years, or forever."

The loss of filming has significant ripple effects for the local economy. “Craftspeople are out of work. Support services like prop shops are closing. CBS recently sold Television City, its West Coast headquarters, which will be redeveloped. At least one entire studio lot -- the historic 20th Century Fox lot, now owned by Disney -- may be vacated, left to an uncertain fate.”

Meanwhile, housing remains unaffordable for many Angelenos. According to UCLA research, “Though Los Angeles recently adopted a massive housing-oriented rezoning program, called CHIPS, ‘Los Angeles will fall far short of its housing production goal’ and will risk ‘displacement of vulnerable households’ unless it supplements the rezoning with an ‘ambitious single-family upzoning policy.’”

Stephens concludes that “Hollywood needs to wake up. The need for housing -- via apartments, ADU's, transit-oriented development -- needs to go viral. Ideally, Hollywood should promote exactly the type of neighborhoods that it likes to shoot. Movies and TV shows disproportionately portray busy, walkable, attractive urban neighborhoods (see related CP&DR commentary) that are easy to create on a studio lot but almost impossible with conventional zoning, financing, and infrastructure. This is the moment when both of these once-great industries, with help from planners, need to recognize their common interests and flip this script.”

• Hollywood
• Los Angeles
• Entertainment Industry
• Housing Crisis

Public spaces are failing teenage girls, asserts Manish Thakre in an opinion piece for Next City. “A 2019 World Health Organization-led study suggests that 85% of school-going adolescent girls worldwide fail to meet the minimum recommended hour of daily physical activity.”

A U.K. study found that more than one million teen girls who considered themselves “sporty” stopped doing sports after primary school, with reasons including “ fear of judgment (68%), lack of confidence (61%), school pressures (47%) and not feeling safe outside (43%).” For Thakre, “These issues underscore the urgent need for gender-sensitive urban planning and recreation policies.”

The United Nations recognizes play and recreation as fundamental rights, Thakre adds. “UNICEF’s guidelines on child-responsive urban planning emphasize five core benefits for children: health, safety, citizenship, environment, and prosperity – yet these are often missing in city design.”

Thakre offers examples from Bath, England and Vienna, Austria, where city officials took concerted steps to prioritize the needs of teen girls in public spaces. “To foster inclusive and safe public spaces, cities must ensure safer streets and accessible open spaces like parks and playgrounds — working with adolescent girls to meet their needs.”

• Girls
• Youth
• Urban Design
• Universal Design
• Inclusivity
• Safety
• Public Space

• "Stay hungry, stay foolish."


• "You can't connect the dots looking forward; you can only connect them looking backwards."


• "Your time is limited, so don't waste it living someone else's life."


• "For the past 33 years, I have looked in the mirror every morning and asked myself: 'If today were the last day of my life, would I want to do what I am about to do today?' And whenever the answer has been 'No' for too many days in a row, I know I need to change something."


• "If I had never dropped in on that single calligraphy course in college, the Mac would have never had multiple typefaces or proportionally spaced fonts. And since Windows just copied the Mac, it's likely that no personal computer would have them."