Science

PACE, a light-based computer chip made by LightelligenceLightelligence Computers that use light rather than electricity to represent and manipulate data could slash the power demands of data centres and simultaneously speed up calculations. Two studies published today describe breakthroughs in running real-world problems on light-based computers, making the technology on the verge of commercial application, say researchers. Electronic computers, like those we all use today, historically followed Moore’s Law: the power of machines doubled every two years. But in recent years, progress has slowed as the miniaturisation of transistors hit fundamental physical limits. Researchers are working on numerous potential solutions, including quantum computing and photonic com...

Photo: Lukasz Kobus/European Commission As exciting as it is when certain records are bested, others are better left alone.  Case in point: Last year was the warmest year on record. Global temperatures in 2024 were 2.3 degrees Fahrenheit (1.28 degrees Celsius) above NASA’s 20th-century baseline (1951-1980), which tops the record set in 2023. The new record comes after 15 consecutive months of monthly temperature records. We need to do a lot more to stop that number from rising, because it’s affecting our day-to-day lives. For instance, there were 27 billion-dollar climate and weather disasters in the U.S. in 2024. (Meaning, of the several climate-related events in this country, 27 of them inflicted damages exceeding $1 billion.)  Many modern conveniences have created an excess...

On a large table draped with hundreds of cables, a maze of mirrors and lenses bounces and guides a thin beam of laser light. It culminates at a silvery capsule, which holds 40,000 strontium atoms cooled to within a whisker of absolute zero. This delicate edifice is an optical clock, one of the world’s most accurate timepieces. Instruments like this aren’t exactly designed to be portable – which makes it more than a little surprising that the operators of one such device at the German national metrology institute packed it into a trailer and sent it hurtling down a motorway. It was the start of a perilous journey: a bad jolt could disrupt the beat of its precise ticks. But it was necessary. That was because, in 2022, scientists globally agreed that we should start work...

Atomic clocks record time using microwaves at a frequency matched to electron transitions in certain atoms. They are the basis upon which a second is defined. But there is a new kid on the block, the optical clock, which boasts even higher accuracy. Is it time to redefine the second? Optical clocks can reach accuracies at the level of 10-18 , “which is a number so accurate that if the clock started running at the big bang, by now it will have lost 1 second”, says Alexandra Tofful, an optical clock physicist at the National Physical Laboratory (NPL) in London, which oversees scientific measurement standards in the UK. Unlike atomic clocks, this new type of timekeeper probes electron transitions with light. “Because visible l...

Archaeologist Kristina Douglass studies how past human adaptation can inform solutions to today’s climate challenges. She and her team work in southwest Madagascar’s Velondriake Marine Protected Area, investigating how communities have adapted to environmental variability over thousands of years. They study archaeological sites, analyze remote sensing data and conduct oral histories to reveal the ways in which Indigenous communities have managed their landscapes and resources sustainably. “It’s like being in a library of human experience and looking for the perfect book to deal with a question that has just come up today,” says Douglass, who is a Columbia Climate School professor and a research scientist at the Lamont-Doherty Earth Observatory. “I really like to think of our wo...