Frequent cannabis users may wake up with unusually high levels of the stress hormone cortisol, suggesting their daily stress rhythms could be disrupted. Researchers say the finding raises questions about whether using cannabis for stress relief might, over time, interfere with the very system that helps the body handle stress.

Full-fat dairy may be healthier than conventional advice has suggested. In a 12-week study, adults who ate three servings a day showed no meaningful increases in weight, body fat, cholesterol, or insulin resistance. They also experienced improved blood pressure and consumed more calcium, protein, and vitamin D. The findings suggest dairy’s complex structure may matter more than its saturated fat content alone.

More than 60,000 years ago, humans in southern Africa were engraving ostrich eggshells with intricate geometric patterns that appear far more organized than previously realized. Researchers found recurring grids, parallel lines, right angles, and repeated shapes, suggesting the designs followed deliberate rules rather than being improvised. The engravers may even have planned entire patterns in their minds before carving them.

Deep underground, bacteria may be capable of doing something remarkable: trapping toxic uranium before it spreads. When researchers fed microbes in uranium-contaminated mine water with glycerol, about 95% of the dissolved uranium disappeared within 130 days. The bacteria helped convert it into an unusually stable uranium compound that had rarely been observed before.

Chemists have developed a catalyst that breaks a long-standing rule governing which molecules receive electrons during chemical reactions. By releasing electrons directly into solution, the technique could unlock reactions—and potentially useful new molecules—that were previously out of reach.

Dinosaurs conquered the land at enormous sizes, but strangely, they almost never evolved into truly tiny animals. New research suggests that physiology alone can’t explain this missing miniature end of the dinosaur spectrum—and that early mammals may have been partly responsible. While dinosaurs kept mammals from becoming large, small mammals may have returned the favor by occupying ecological niches that could otherwise have supported mouse-sized dinosaurs.

A study tracking more than 340,000 adults for over a decade found that heavy drinking increased the risk of death regardless of beverage type. At lower levels, however, the picture became more surprising: beer, cider, and spirits were linked to higher mortality, while wine was associated with lower risk. Moderate wine drinkers had a 21% lower risk of cardiovascular death compared with people who rarely or never drank.

Atomically thin semiconductors could enable dramatically smaller and more efficient chips, but a stubborn problem at the boundary between materials has limited their performance. Researchers have now engineered that atomic interface to protect electron flow while still allowing extremely thin insulating layers. The resulting transistors delivered an unusually strong combination of electrical control and performance.

An intensive seven-day meditation retreat triggered striking changes across the brain and body, including shifts tied to neuroplasticity, immunity, metabolism, and natural pain relief. Participants also showed brain connectivity patterns resembling those associated with psychedelic experiences, suggesting that powerful altered states may be achievable without drugs.

Stress may literally scramble the brain’s internal GPS. Researchers found that cortisol, a hormone released during stress, made people significantly worse at navigating a virtual environment and disrupted the precise activity of grid cells, specialized brain cells that help us understand where we are in space. When landmarks were missing, this navigation system nearly stopped functioning, while another brain region appeared to step in and compensate.

CT scans of the world’s rarest dodo skulls suggest the extinct bird may have had a stronger sense of smell, a highly sensitive beak, and a lifestyle that extended into dawn and dusk. The discoveries are helping overturn centuries-old myths and reveal a far more complex animal than the famously “dumb” dodo of popular imagination.

A rare meteorite that crashed through a New Jersey roof contains evidence of ancient salty fluids, organic compounds, and amino acids from a primitive asteroid. Its pristine chemistry could offer new clues about how space rocks helped supply early Earth with some of the ingredients needed for life.

A new nanostructured carbon design lets fuel-cell catalysts use tiny amounts of platinum while remaining remarkably stable and efficient. The breakthrough could help hydrogen fuel cells become a more practical way to power data centers, vehicles, and other energy-intensive technologies.

Getting the recommended 150 minutes of moderate-to-vigorous exercise each week may offer only modest protection against heart attacks and strokes. A large study suggests that substantially greater benefits may require roughly 560 to 610 minutes a week—nearly 9 to 10 hours of brisk walking, running, cycling, or similar activity.

A protein that evolved long before the human circulatory system may help unlock stronger cancer treatments. When C3 is produced inside tumors, it blocks immune-suppressing cells and gives immunotherapy a better chance to work. Researchers were even able to recreate this effect in resistant tumors, significantly improving survival in mice.

Scientists have created the first quantum material that can sort and transport different quantum states of light at room temperature, potentially removing the need for bulky, ultra-cold refrigeration systems. Built from a gold film carved with hundreds of microscopic structures, the ultrathin “metacrystal” acts like a filter that directs different kinds of quantum light along separate paths while preserving the information they carry.

Scientists have discovered incredibly tiny plasma whirlpools swirling across the Sun’s surface, some just 20 kilometers wide. These previously invisible vortices may twist magnetic fields and help build up the energy released in small solar eruptions called nanoflares. They may also help magnetic fields spread through the Sun’s atmosphere far faster than current models can explain.

Changing how much sweet-tasting food people eat may not change how much they crave or enjoy sweetness after all. In a six-month trial, researchers found that people assigned to high-, low-, or average-sweetness diets showed no meaningful differences in their preference for sweet foods, body weight, or markers linked to diabetes and heart disease. Many participants also drifted back toward their previous eating habits once the trial ended.

Scientists have generated quantum entanglement directly from sunlight, potentially offering a lower-energy alternative to the lasers normally used in quantum technology. Their outdoor experiment produced entangled photons with about 94% similarity to an ideal state. The result could pave the way for simpler quantum satellites, secure communications, and more energy-efficient quantum computing.

Teens who start using cannabis may experience slower growth in memory, attention, language, and processing speed. Their abilities often developed normally at first, then began leveling off while nonusers continued improving. THC appeared to be the most likely driver, especially for worsening memory.