A long-standing law of thermodynamics turns out to have a loophole at the smallest scales. Researchers have shown that quantum engines made of correlated particles can exceed the traditional efficiency limit set by Carnot nearly 200 years ago. By tapping into quantum correlations, these engines can produce extra work beyond what heat alone allows. This could reshape how scientists design future nanoscale machines.

Two physicists at the University of Stuttgart have demonstrated that the Carnot principle, a foundational rule of thermodynamics, does not fully apply at the atomic scale when particles are physically linked (so-called correlated objects). Their findings suggest that this long-standing limit on efficiency breaks down for tiny systems governed by quantum effects...

Some stars appear to defy time itself. Nestled within ancient star clusters, they shine bluer and brighter than their neighbors, looking far younger than their true age. Known as blue straggler stars, these stellar oddities have puzzled astronomers for more than 70 years. Now, new results using the NASA/ESA Hubble Space Telescope are finally revealing how these “forever young” stars come to be and why they thrive in quieter cosmic neighborhoods.

Why blue stragglers puzzle astronomers
Blue straggler stars stand out in old star clusters because they appear hotter, more massive and younger than stars that should all have formed billions of years ago...

The ubiquity of smart devices—not just phones and watches, but lights, refrigerators, doorbells and more, all constantly recording and transmitting data—is creating massive volumes of digital information that drain energy and slow data transmission speeds. With the rising use of artificial intelligence in industries ranging from health care and finance to transportation and manufacturing, addressing the issue is becoming more pressing.

A research team led by the University of Massachusetts Amherst aims to address the problem wi...

New observations reveal how solar flares really ignite—and why they can be so powerful. Solar Orbiter has captured the clearest evidence yet that a solar flare grows through a cascading “magnetic avalanche.” Small, weak magnetic disturbances rapidly multiplied, triggering stronger and stronger explosions that accelerated particles to extreme speeds. The process produced streams of glowing plasma blobs that rained through the Sun’s atmosphere long after the flare itself.

Much like a snow avalanche that starts with a small shift before cascading downhill, new observations show that solar flares begin with subtle magnetic disturbances that rapidly intensify...