Quantum physics may place a fundamental limit on clock precision, hinting that time itself is not perfectly precise. Unconventional quantum theories may imply that time itself has a tiny fundamental uncertainty, placing an ultimate limit on how precisely any clock could measure it. The effect is far beyond current detection, but it could reveal a hidden connection between quantum mechanics, gravity, and spacetime.

Quantum mechanics has always challenged our everyday understanding of reality. In the quantum world, particles can exist in a superposition of states, meaning they can occupy multiple possible positions or configurations at the same time. Physicists describe these possibilities mathematically using a wavefunction.

That picture is very different from ordinary life, wher...

A new UCLA study has found a connection between how quickly the brain ages and the bacteria and chemical byproducts found in the gut, offering a clue to what drives brain aging long before symptoms appear.

Researchers have long used brain scans to estimate a person’s “brain age,” a measure that can differ from someone’s actual age in years. When a brain looks older than expected on a scan, prior research has linked it to poorer memory, thinking skills and mood. However, most of these studies involved older adults or people with existing brain diseases. Whether this gap between brain age and chronological age means anything in younger, generally healthy people has been unclear.

In a new study published in the journal eBioMedicine, UCLA Health rese...

Within tiny halos of light clinging to a vanishingly thin wisp of optical fiber, scientist Jongmin Lee guides atoms like marbles through a narrow pipe. Rock the fiber and the atoms shift side by side; they just don’t fall off. But don’t be deceived by the seemingly delicate nature of his experiment. Lee is exploring how to measure motion precisely in rough-and-tumble environments.

A quantum sensing scientist at Sandia National Laboratories, Lee is an expert in a type of motion sensor...

Scientists have discovered that there is ice deep inside planets like Neptune and Uranus and want to find out what form it takes and how it behaves. They cannot dig for it and transport it all the way back to Earth, so they do the next best thing: recreate those extreme conditions in the lab.

That’s exactly what a team of scientists led by Alexis Forestier from the CEA, France’s Alternative Energies and Atomic Energy Commission, did. What they discovered could help us better understand the strange magnetic fields and deep interior layers of these distant worlds.

The weird world of hot ice
On those planets, ice is not like the frozen cubes you put into a cold drink...