Einstein’s claim that the speed of light is constant has survived more than a century of scrutiny—but scientists are still daring to test it. Some theories of quantum gravity suggest light might behave slightly differently at extreme energies. By tracking ultra-powerful gamma rays from distant cosmic sources, researchers searched for tiny timing differences that could reveal new physics. They found none, but their results tighten the limits by a huge margin.

When scientists repeatedly drove a strongly interacting quantum system with laser “kicks,” they expected it to heat up and grow chaotic. Instead, the atoms abruptly stopped absorbing energy and locked into a stable pattern of motion. This strange effect arises from quantum coherence, which prevents the system from thermalizing despite constant forcing. The results overturn classical intuition and offer new insight into how quantum systems can resist disorder.

Nearly everything in the universe is made of mysterious dark matter and dark energy, yet we can’t see either of them directly. Scientists are developing detectors so sensitive they can spot particle interactions that might occur once in years or even decades. These experiments aim to uncover what shapes galaxies and fuels cosmic expansion. Cracking this mystery could transform our understanding of the laws of nature.

Scientists are uncovering why Brazil may be one of the most important yet underused resources for studying extreme longevity. Its highly diverse population harbors millions of genetic variants missing from standard datasets, including rare changes linked to immune strength and cellular maintenance. Brazilian supercentenarians often remain mentally sharp, survive serious infections, and come from families where multiple members live past 100. Together, they reveal aging not as inevitable decline, but as a form of biological resilience.

A brief, intense workout may do more than boost fitness—it could help fight cancer. Researchers found that just 10 minutes of hard exercise releases molecules into the bloodstream that switch on DNA repair and shut down cancer growth signals. When these molecules were applied to bowel cancer cells, hundreds of cancer-related genes changed activity. The discovery helps explain how exercise lowers cancer risk and hints at future therapies inspired by movement.

Exercise doesn’t just challenge the body; it challenges how the brain interprets effort. Scientists discovered that vibrating tendons before cycling allowed people to push harder without feeling like they were working more. Their muscles and hearts worked overtime, but their sense of strain stayed the same. This brain-body mismatch could one day help make exercise feel less intimidating, especially for people who struggle to stay active.

A large review of studies suggests that exercise can ease depression about as effectively as psychological therapy. Compared with antidepressants, exercise showed similar benefits, though the evidence was less certain. Researchers found that light to moderate activity over multiple sessions worked best, with few side effects. While it’s not a cure-all, exercise may be a powerful and accessible tool for many people.

Scientists have detected a surprisingly hot galaxy cluster dating back to the universe’s infancy. The cluster formed far earlier and burned far hotter than current models predict. Researchers believe supermassive black holes may have rapidly heated the surrounding gas. The finding could force a major rethink of how galaxy clusters grow.

Europa’s buried ocean has made it one of the most exciting places to search for life beyond Earth. However, new calculations suggest its seafloor may be calm, cold, and largely inactive, with little energy to support living organisms. Unlike Jupiter’s volcanic moon Io, Europa experiences weaker tidal forces that fail to drive underwater geology. The ocean may exist, but it could be a very quiet place.

Around the bright star Fomalhaut, astronomers spotted glowing clouds of debris left behind by colossal collisions between large space rocks. One of these clouds was even mistaken for a planet before slowly fading away. Seeing two such events in just two decades hints that violent impacts may be surprisingly common in young star systems. It’s like watching planets-in-the-making collide before our eyes.

Bariatric surgery far outperformed GLP-1 weight loss drugs in a new real-world comparison of more than 50,000 patients. Two years after treatment, surgery patients lost about 58 pounds on average, while those using semaglutide or tirzepatide lost roughly 12 pounds. Even patients who stayed on GLP-1 drugs for a full year saw much smaller results than surgical patients. High dropout rates and real-world challenges appear to blunt the drugs’ effectiveness.

Researchers at TU Wien have discovered a quantum system where energy and mass move with perfect efficiency. In an ultracold gas of atoms confined to a single line, countless collisions occur—but nothing slows down. Instead of diffusing like heat in metal, motion travels cleanly and undiminished, much like a Newton’s cradle. The finding reveals a striking form of transport that breaks the usual rules of resistance.

Tessellations aren’t just eye-catching patterns—they can be used to crack complex mathematical problems. By repeatedly reflecting shapes to tile a surface, researchers uncovered a method that links geometry, symmetry, and problem-solving. The technique works in both ordinary flat space and curved hyperbolic worlds used in theoretical physics. Its blend of beauty and precision could influence everything from engineering to digital design.

Researchers in Japan built a miniature human brain circuit using fused stem-cell–derived organoids, allowing them to watch the thalamus and cortex interact in real time. They found that the thalamus plays a decisive role in maturing the cortex and organizing its neural networks. Signals from the thalamus triggered synchronized activity in specific neuron types, while others remained unaffected. The system closely mimics human brain development and could transform how scientists study neurological disorders.

Researchers have reconstructed ancient herpesvirus genomes from Iron Age and medieval Europeans, revealing that HHV-6 has been infecting humans for at least 2,500 years. Some people inherited the virus directly in their DNA, passing it down across generations. The study shows that these viruses evolved alongside humans—and that one strain eventually lost its ability to integrate into our chromosomes. It’s the first time this long, intimate relationship has been proven with ancient genetic evidence.

Spruce bark beetles don’t just tolerate their host tree’s chemical defenses—they actively reshape them into stronger antifungal protections. These stolen defenses help shield the beetles from infection, but one fungus has evolved a way to neutralize them. By detoxifying the beetles’ chemical armor, the fungus can successfully invade and kill its host. The discovery sheds light on an unseen forest arms race and may improve biological pest control.

Scientists have discovered that wildfires release far more air-polluting gases than previously estimated. Many of these hidden emissions can transform into fine particles that are dangerous to breathe. The study shows wildfire pollution rivals human-made emissions in some parts of the world. This helps explain why wildfire smoke can linger and worsen air quality long after the flames are gone.

Global cancer cases have surged dramatically, doubling since 1990 and reaching 18.5 million new diagnoses in 2023. Deaths have also climbed to over 10 million a year, with the steepest increases hitting low- and middle-income countries. Without urgent action, researchers project more than 30 million new cases annually by 2050. Alarmingly, around four in ten cancer deaths are tied to preventable risks such as smoking, poor diet, and high blood sugar.

Researchers have developed a magnetic nanomaterial that can kill bone cancer cells and support bone regeneration at the same time. The material heats up under a magnetic field to destroy tumors, while its bioactive coating helps it bond to bone and stimulate healing. Tests showed rapid formation of bone-like minerals, a key sign of successful integration. The breakthrough could lead to smarter, less invasive treatments for bone tumors.

Scientists have created a new way to watch plants breathe—live and in high definition—while tracking exactly how much carbon and water they exchange with the air. The breakthrough could help unlock crops that grow smarter, stronger, and more drought-resistant.