If humanity intends to engage in interstellar exploration in the near future, lightsails are currently the best option. This technology, consisting of laser arrays pushing a reflective sail and tiny spacecraft to relativistic speeds (a fraction of the speed of light), is presently the only promising method for sending missions to the nearest stars within a human lifetime. Alas, several major hurdles need to be overcome and technological developments made before any such missions are possible.

These range from developing space-based laser systems and creating materials that can survive the journey through interstellar space to testing proof of concepts in space. According to recently published results, engineers at Cornell University's Space System Design Studio (SDSS) successfully deployed two lightsail experiments - Alpha CubeSat and Sailing to the Stars - from the International Space Station (ISS).

The missions were created as part of the Museum of Science Fiction’s 2016 CubeSat Competition, a design competition for next-generation spacecraft concepts using off-the-shelf technologies. The experiments were funded by NASA's CubeSat Launch Initiative, which launched to the ISS in late 2025 aboard the NG-23 and Crew-11 missions, respectively. Both consist of origami-style lightsails and chip satellites (ChipSat) that were folded for launch (to conserve room for other payloads) and unfurled upon deployment...

Everything that’s swept the world since the 2022 release of ChatGPT — “the AI economy”; data centers; chatbots acting as best friends, doctors, and mathematicians; talk of existential risk — it all starts, in some sense, with an intern in a University of Montreal lab named Dzmitry Bahdanau.

It was 2014. The 23-year-old Belarusian, who had been coding competitively since he was a kid but hadn’t done academic research before, was asked to help figure out how to get a computer to translate sentences from English to French. Bahdanau was working with artificial neural networks, which had already shown promise in pattern-recognition tasks such as deciphering handwriting and identifying objects in photos. The networks learn to recognize patterns by strengthening and weakening connections between nodes in response to training data. Bahdanau quietly doubted their potential to achieve anything like human-level intelligence, but his adviser, the computer scientist Yoshua Bengio, and the postdoc on the project, Kyunghyun Cho, were believers. And translation was widely seen as a formidable and interesting problem for neural networks to try to solve.

Translation is not as simple as swapping each English word for a French one. Languages have different grammatical structures and are riddled with idioms and connotations, all of which had long stymied attempts to automate the process. You can’t simply implement rules of translation because there are none. But neural networks seemed promising because they learn by example. They can be trained on huge databases of paired English and French sentences to, eventually, absorb the quasi-rules, exceptions, and subtleties.

Results had been mediocre, though; the longer the sentence, the worse neural networks performed. That’s because researchers were trying to cram each sentence’s data into a fixed amount of memory before decoding the sentence in the target language. It was a bottleneck that limited how complex and sophisticated translations could be. The network architecture just wasn’t right.

So Bahdanau tried something different. “It was just obviously the right thing to do — one of these things that happens once in a while in science where it’s just very clear to someone who is not very experienced in the field,” he recalled, speaking to me from Montreal, where he still works in AI. “And it just worked. From the very first attempt.”

Bahdanau’s trick, a mathematical operation that he, Cho, and Bengio referred to as “attention,” enabled their neural network to translate long sentences just as well as short ones. That meant the approach was scalable. Other AI researchers at the time quickly integrated attention into their neural network designs. Then, in 2017, a team at Google devised a new kind of neural network architecture called a transformer that supercharged the attention method and stripped away everything else. The team’s paper, “Attention Is All You Need,” reported that transformers achieved state-of-the-art translation while requiring a fraction of the computation needed to train prior models. The paper, which has since been cited more than 250,000 times, was a watershed moment in AI. Large language models such as ChatGPT and Claude followed.

Given the staggering power that’s been unleashed, it’s worth asking what this attention mechanism is exactly, why it is “all you need,” and why machine translation was the task that unlocked it all. Attention is a way for us to understand how a single AI model can converse with us, diagnose diseases, generate realistic videos, solve long-standing math problems, and more. Is it somehow at the heart of intelligence — artificial and otherwise?

Imagine a medicine that stops seizures at their source, switches off instructions that keep a cancerous tumor growing and prevents Alzheimer's from stealing memories and wreaking havoc on the brain.

The basis for such treatment is already here. Known as oligonucleotides [pronounced ah-lee-go-noo-klee-oh-tides], these drugs are made from small bits of DNA or RNA—the blueprint cells use to make proteins.

While most drugs act on the finished products, oligonucleotides cut to the chase and intervene upstream, before the proteins have a chance to roll off the cellular assembly line. They can block production of harmful proteins or help cells make ones they need by tinkering with the instructions.

There's one big catch, however.

"Knowing what gene to target is only part of the problem," said Northeastern chemistry and chemical biology professor Ke Zhang, who is developing ways to make oligonucleotides more effective. "The other part is getting the drug to the right place in the right cells."

In the Journal of the American Chemical Society, Zhang and his colleagues present research that suggests a new way to get oligonucleotides into body tissues. The molecular structures his lab is developing shuttle the drugs to their destinations.

They resemble tiny bottlebrushes, with bristles that protect the medicines attached to them. The secret to their success lies in a short sequence of chemical building blocks incorporated into their structure. It acts as a set of delivery instructions to steer the medicine toward particular tissues.

By helping genetic medicines reach their target, this approach could unlock their potential to tackle diseases that are currently untreatable...

When Christopher Columbus made landfall in the Americas on Oct. 12, 1492, he encountered Indigenous Lucayans living on the Bahamian island now called San Salvador. Columbus wrote in his diary about "great multitudes of men" who greeted him that day, bartered with him and told him about other groups who lived on nearby islands.

But within a few decades after Columbus' arrival, the Indigenous people of the Americas were decimated by what anthropologist Eric Wolf called the "Great Dying" — a combination of epidemic disease, warfare and enslavement that led to a rapid decline in the Native population.

For centuries, researchers have been trying to figure out how many Indigenous people lived in the Americas just prior to the fateful arrival of European colonizers.

The answer to that question has been surprisingly elusive, and estimates based on historical censuses, archaeological sites and land carrying capacity in the Western Hemisphere have varied wildly.

Recent research into Native American demography has revealed that the population peaked several centuries before Europeans showed up on the shores of North America — and that if Europeans had arrived at that peak, the entire history of the continent may have been different...

After five-and-a-half years on Mars, NASA's Perseverance Rover has set a distance record for travel on another world. Since landing in Mars' Jezero Crater, an ancient paleolake, on February 18, 2021, Perseverance has travelled 45.22 km, or 28.10 miles. That puts it slightly ahead of NASA's Opportunity rover, which travelled 45.16 kilometers (28.06 miles) during its mission. It must be noted, however, that Perseverance took only 5.5 years to travel this far, while Opportunity required almost 15 years.

Comparing the plutonium-powered Perseverance to the solar-powered Opportunity is unfair. But in any case, Perseverance deserves recognition for this milestone.

“The original mission called for no more than 12.4 miles of driving. We’ve blown well past that..." - Steven Lee, Perseverance and Curiosity project manager, JPL/NASA.

Perseverance is currently in a region named “Lac de Charmes,” which is off the western end of Jezero Crater. It reached its new milestone while heading toward a feature named "Idubi," a scientific target notable for its ancient rocks. On Earth, there are no rocks as old as these because they've all been destroyed by plate tectonics.

Perseverance has found igneous rocks, a surprising result considering that scientists expected to find mostly sedimentary rocks. In fact, a primary reason Jezero Crater was chosen as the mission's landing site is because sedimentary rocks are good at preserving evidence of ancient life. While the rover found plenty of sedimentary rocks, it found igneous rocks, along with fluorite, which forms when rock interacts with heated water. This is evidence of hydrothermal activity, and scientists are hoping Perseverance will find more traces of ancient hydrothermal systems at Idubi...

Plastics are supposed to be chemically inert. It's the reason they're used so frequently to package food, bottle water and create children's toys: They're safe. But something important happens when a large piece of plastic fragments into micro- and nanoparticles. Its surface area increases dramatically relative to its volume. Vastly more of the material is now exposed to its surroundings.

A new study by researchers from Columbia University and the University of California, Berkeley, found that this newly created surface is not necessarily safe and identified the chemical reasons why.

"As plastic fragments into smaller and smaller particles, its surface area increases enormously. Then microplastics change the water that surrounds them, generating high-energy, reactive radicals (reactive oxygen species, ROS) that very likely contribute to biological damage that we see in animals and potentially in humans as a result of microplastic exposure," said Wei Min, a Columbia professor of chemistry and biomedical engineering.

The work challenges the common view of microplastics as largely passive fragments of inert material and contributes to a growing understanding of why the large-scale presence of microplastics is a cause for concern. The research was published today in the journal Nature.

Water-rich tissues raise health concerns
This is particularly noteworthy for human health because human blood is approximately 50% water, and individual human cells are generally 60% to 80% water. The new research suggests that microplastics that enter the bloodstream or cells could remain chemically active in this water-rich biological environment.

DYK that you’re moving at about 67,000 miles per hour right now?!

Earth is carrying you on its orbit around the Sun. When Roman launched, it inherited that motion and will undergo a series of maneuvers before its final orbital insertion at L2.

nasa.tumblr.com/post/830641383…

The year 2026 has been an expensive one for social media platforms. Since March, YouTube and Meta, the parent company of Instagram and Facebook, have settled or paid out in multiple lawsuits totaling more than $17 billion for allegedly acting negligently, deliberately designing their platforms to hook kids and misleading the public about safety and privacy. If these suits are any indication of how states and the public are starting to view social media platforms, more may follow.

On top of these lawsuits, social media platforms are facing a loss of business as bans for minors are accelerating and spreading worldwide. Australia was one of the first with a ban on kids under 16 on social media starting in December 2025, followed soon after by the U.K. with a similar prohibition.

The current list of countries looking to ban minors from these platforms includes more than 20, from Greece to the United Arab Emirates to Canada. The proposed and enacted bans around the world vary in terms of age restriction, parental consent rules and age verification methods. Different countries are looking at restricting different platforms, but most include a mix of Snapchat, YouTube, TikTok, Instagram, Facebook and X.

These bans aren't necessarily for mental health reasons only—some are motivated by political concerns about foreign-owned platforms, and others aim to protect young people's privacy. But nearly every government banning social media platforms for young people mentions their mental health as a reason.

The question is, are these bans the solution to the mental health problems young people are facing? I research digital media and marketing and measure the impact of new technologies, and I'm skeptical about whether prohibiting access to these platforms will improve young people's mental health.

Mental health concerns
Since Jonathan Haidt's 2024 book "The Anxious Generation," critics of social media have increasingly focused on young people's mental health. Haidt argues that social media disrupts kids' social and neurological development, contributing to rising anxiety and depression through sleep loss, fragmented attention, addiction, loneliness, social comparison and perfectionism.

A 2026 study found that young people between 14 and 20 are more than 100% more likely to experience mental illness than 14- to 20-year-olds 50 years ago.

Increased use of social media and screen time is compounding an already precarious time for minors. In 2021, it was estimated that 20.5% of young people experienced elevated symptoms of anxiety, and 25.2% of youth reported elevated symptoms of depression globally.

Many factors contribute to this, including better screening and awareness of kids' mental health problems, as well as societal disruptions as a result of the COVID-19 pandemic. As the world sheltered in place and moved online for work, school and social interactions, there was an increase in isolation and loneliness.

Not all bad
In light of these concerns, some researchers argue that bans on social media platforms are like putting an age restriction on buying alcohol or cigarettes.

But unlike these addictive and potentially harmful substances, there are benefits to social media, especially for teens who feel disconnected from their local communities and want to build relationships with others who feel similarly.

Social media platforms allow for global connectivity and community-building with like-minded groups. They also provide a place for self-expression and civic engagement...

On the evening of 8 September 1930, the German mathematician David Hilbert stepped up to a microphone in Königsberg and addressed his countrymen by radio. He was 68, recently retired, and at the height of his fame. The talk was a defence of pure reason, delivered in the city of Immanuel Kant, and it ended with two phrases that would later be carved on his tombstone: Wir müssen wissen. Wir werden wissen. We must know. We shall know.

Are certain questions closed to the human mind? Are there truths about the world that we can never know? Hilbert thought that, at least within mathematics, this could not be the case. For him, mathematics was a game played with symbols: one could fix the right axioms as rules of the game and every mathematical problem could be solved. He was wrong.

The day before his Königsberg address, at a small academic meeting in the same city, a 24-year-old Austrian named Kurt Gödel had quietly announced that no such system for arithmetic could exist. Whatever reasonable set of rules you fix, something true must lie beyond them and thus beyond our knowledge. We can’t know. We won’t know. Gödel’s results, known as the Incompleteness Theorems, are landmark achievements of 20th-century logic. Recent work in philosophy and mathematics has begun to illuminate the gap they opened, and with it something deeper about the foundations of knowledge itself. The story begins in the same city, but two centuries earlier.

When Kant remembered a book by David Hume he’d read years earlier, he was woken from what he called his ‘dogmatic slumber’. Kant had believed that pure reasoning could teach us every absolute truth about the world, but Hume had asked a question that that stumped him: what reason do we actually have to believe that the future will resemble the past? We may have seen the Sun rise a thousand times, but how do we know it will rise tomorrow? The belief that the future will resemble the past is, Hume argued, merely a kind of habit. Kant couldn’t answer Hume’s challenge and was silenced for a decade.

For Hume, proving a theorem was like unpacking a suitcase to find an outfit. Kant could not leave it there

When Kant finally broke his silence with the Critique of Pure Reason (1781), he offered a radical answer. We can know the world only as it appears to our minds, and that is where our science sits; the noumenal world – the Ding an sich (the ‘thing-in-itself’) – simply lies beyond our reach. Causation is not something we discover in the world, but something the mind supplies for experience to be coherent at all. When we watch a cat push a glass off a table, we don’t see a bare sequence of motions and then infer, by some metaphysical principle, that the push caused the fall. No: we see the push as causing the fall. The causal structure is not a hypothesis we add to the experience; it is part of how the experience comes to us in the first place. It is in our minds already.

So far, so good: Kant has met Hume’s challenge, and the workings of science are intelligible: we are structuring our experiences. But the work is not done, for there remains mathematics, the very language in which the sciences are framed. Hume was content that arithmetic and algebra are merely the unpacking of definitions; that proving a theorem is like unpacking a suitcase to find an outfit. Kant could not leave it there. If mathematics were only such unpacking, how could it underwrite the sciences? Either the sciences tell us nothing new about the world, or something has gone missing from the account...

The chief aim of NASA's Artemis Program is to create a "sustained program of lunar exploration and development." Beyond returning astronauts to the Moon for the first time since the Apollo Era, NASA and other space agencies hope to build the infrastructure that will enable regular, long-duration missions to the lunar surface. In addition to targeting the South Pole-Aitken Basin, NASA is eyeing lunar caves as a potential site for habitats and other lunar facilities.

Meanwhile, space agencies need to send large amounts of cargo and robotic explorers to the surface. This includes the Geophysical Instruments for Marius Lunar pit Investigation (GIMLI), a Planetary Science Institute-led proposal that will investigate a "skylight," a hole in an old lunar lava tube, to see if a large cave system extends beyond it. Such a location could provide a safe place for astronauts to operate on the surface in the future.

The mission team will be led by PSI Associate Director and Senior Scientist Than Putzig. The work will be carried out in partnership with the Norwegian Space Agency, while Honeybee Robotics will create much of the robot's equipment and instrumentation. NASA will provide a lander and rover element through its Commercial Lunar Payload Services (CLPS), and funding will be provided through NASA’s Payloads and Research Investigations on the Surface of the Moon (PRISM) program.

Said PSI Director and CEO Amanda Hendrix:
GIMLI represents the type of ambitious planetary science that PSI was built to pursue. Than and his team are taking a scientific question we’ve been studying from orbit and have developed a way to investigate it directly on the Moon. We’re excited to have PSI leading this effort and to be partnering with NASA and Honeybee Robotics to learn more about the Moon and its volcanic past.

Observations by lunar orbiters have provided compelling evidence of underground caves. This is evident from surface features like sinuous rilles (collapsed lava tubes) and the aforementioned skylights. Researchers theorize these latter features are openings leading to stable lava tubes left over from when the Moon was still geologically active (ca. 3.8 and 3 billion years ago).

Observations from lunar orbit have provided compelling evidence that caves and lava tubes may exist under the Moon’s surface. GIMLI’s research will focus on the Marius Hill Pit (MHP), a large hole in one of the Moon’s most volcanically diverse regions. Like other lunar pits, MHP may serve as an opening to these underground spaces, which may have formed during ancient volcanic activity. One in particular is the Marius Hill Pit (MPH), a prominent skylight on the nearside's Oceanus Procellarum...

A major software advance could aid the creation of bigger, more reliable quantum computers, a study suggests. Researchers have developed an algorithm that enables off-the-shelf computers to run quantum simulations previously only possible using the world's most powerful supercomputers.

It means the simulations can be run using around 5% of the computing power previously needed to perform them with a supercomputer, the team says.

The advance could make it cheaper and easier to run experiments vital for understanding the limitations of current quantum computers and informing the design of improved devices, experts say.

Simulations confront quantum computing's limits
Quantum computers could, in theory, perform calculations far beyond the capabilities of even the most advanced supercomputers, but current devices are small and error-prone, hindering their performance.

Key to informing the creation of bigger, more reliable quantum computers is the development of algorithms to simulate how devices might work in reality. However, running these simulations has until now required vast amounts of computing power available at only a handful of facilities worldwide.

The new algorithm was developed by a team led by scientists at the University of Edinburgh and EPCC, the U.K.'s first National Supercomputing Centre, which is part of the university.

Standard computers tackle light-based quantum simulations
The work could aid the development of light-based quantum devices, one of several branches of current quantum research by academics and industry, the team says.

For the first time, the algorithm enables standard computers to run so-called Gaussian boson sampling, a simulation designed to demonstrate the superior capabilities of quantum devices powered by light—known as photonic quantum computers.

In tests, researchers found that classical computers using the algorithm could match and even outperform some current quantum devices' ability to run the simulations...

Leap seconds have driven a raging debate in the metrological community for three decades. Now, that argument has been put to rest: The leap second is officially dead.

Doing away with an obscure metric the average person has been blissfully unaware of may seem like a novelty, but killing the leap second has major ramifications for technology you rely on every day. It also helps stave off what could’ve been a dangerous moment in time: The possibility of the world’s first negative leap second.

The International Bureau of Weights and Measurements (known by its French acronym BIPM) on Thursday said that in May 2027 it would stop issuing leap seconds, 32 of which have been added since 1972 to adjust what’s known as Coordinated Universal Time (UTC).

The world implemented the leap second in 1972 due to a growing gap between time measured with atomic clocks and time based on the Earth’s rotation. The reason for the discrepancy? The latter is slowing down due in large part to tidal friction caused by the moon and Earth’s rotation not lining up. The molten core of the Earth as well as oceans and the atmosphere also affect the spin rate.

Leap seconds are a way to keep atomic-clock-driven UTC in line with astronomically kept Universal Time (UT1). Think of it like adding a little extra track for a train to keep running exactly parallel with another one. Rather than happening on a set interval—like a leap year—BIPM uses the average of hundreds of atomic clocks around the world and compares their time calculations to astronomical time to determine when a leap second is necessary. The most recent one was added in 2016.

Of course, adding track is no small effort, and it may seem like a lot of hassle for a measly second. But UTC is vital for all sorts of technology given the number of APIs and databases that rely on it. Introducing a leap second helped keep UTC and UT1 aligned, but it also wrought havoc on various systems running on UTC and forced companies to figure out how to deal with them when they were added every few years...

Stellar cores called white dwarfs come in an astonishing array of colors, including what scientists say is the first known green star and the reddest star ever found, new research reveals.

A white dwarf star is the dense, cooling core that remains after a low- to medium-mass star runs out of fuel. The new study, published Thursday (Oct. 15) in the journal RAS Techniques and Instruments, shows that white dwarfs come in far more colors than their name suggests.

White dwarf stars got their moniker because the first known examples glowed in either white or pale blue. The new study, however, suggests that "white" dwarfs also emit visible-light colors like pink, green, cyan, purple and yellow.

"Most stars, including most white dwarfs, behave like 'perfect radiators,' so their colour is set almost entirely by temperature. But nobody had really looked into what else might be possible for white dwarfs," Mark Hollands, an astronomer at the University of Warwick in the U.K. and first author of the study, said in a statement. "It turns out these incredibly dense stars can produce colours nobody expected, and some of them genuinely surprised me."

The variety of colors is possible due to white dwarfs' densities compared with main-sequence stars, the study suggests. Cooler white dwarfs have a density of about 1 gram per cubic centimeter, much like flowing water on Earth. The density of these white dwarfs is also millions of times denser than the sun's visible surface, or photosphere, leading to unusual conditions...

Spacecraft propulsion traditionally relies on volatile fuels and separate, bulky systems for different types of maneuvering in space. NASA is working to change that. Engineers at NASA's Marshall Space Flight Center in Huntsville, Alabama, recently completed a series of environmental and physical tests on a new small satellite designed to make spaceflight safer and more efficient.

The ASCENT (Advanced Spacecraft Energetic Non-Toxic) Propulsion Dual Mode mission is a flight demonstration of a spacecraft about the size of a large shoebox. The mission will test a single, integrated propulsion system that uses a common fuel tank to feed two types of engines.

Typically, spacecraft carry two separate propulsion systems to navigate: a high-thrust chemical system for rapid movements like entering orbit, and a low-thrust electric system for efficient, slow maneuvers like maintaining a position. This requires multiple fuel tanks and heavy plumbing, which take up valuable space and add weight.

The spacecraft being developed uses a single nontoxic propellant called ASCENT. By feeding both a high-thrust combustion engine and low-thrust electrospray thrusters from one central tank, the spacecraft saves mass and volume. For future missions, this means more room for scientific instruments and the ability to launch on smaller, less expensive rockets...

The year is 2050, and as the sun sets, the night's first constellations emerge in perfect rows. But these amber-glowing arrays aren't stars at all; they're satellite clusters, harvesting the day's last rays before beaming their power back to Earth.

If it reads like science fiction, that's because it started that way. Called space-based solar power (SBSP), the concept featured prominently in the techno-utopian imaginations of 20th-century visionaries and writers. But for decades, it was dismissed — a pie in the sky proposal.

Now, as a new space race heats up, governments and private companies in China, the U.S., the U.K. and Japan are developing several projects to reassess the idea's feasibility. These include China's ZhuRi ("Chase the Sun") program, Japan's OHISAMA project, the U.K.'s Space Solar, and power-beaming experiments by Caltech and the Air Force Research Laboratory in the U.S., all of which are targeting test launches in the next five years.

Proponents say the technology has the potential to meet Earth's energy needs many times over while causing minimal harm to the environment. But first it needs to get off the ground: In the eyes of critics, space-based solar power is exorbitantly expensive, riddled with untested assumptions, and far too complex to be deployed in time for an urgent green-energy transition.

The challenges include getting the massive solar-panel-covered satellites into space; assembling them; getting those solar panels to constantly face our star; and then finding ways to convert, concentrate and transmit their collected power back to Earth...