ILA physicists have measured Albert Einstein's theory of general relativity, or more specifically, the effect called time dilation, at the smallest scale ever, showing that two tiny atomic clocks, separated by just a millimeter or the width of a sharp pencil tip, tick at different rates.

The experiments, described in the Feb. 17 issue of Nature, suggest how to make atomic clocks 50 times more precise than today's best designs and offer a route to perhaps revealing how relativity and gravity interact with quantum mechanics, a major quandary in physics.

Fiber reinforced composites (FRCs), which are engineering materials comprising stiff fibers embedded in a soft matrix, typically have a constant fiber radius that limits their performance. Now, researchers from the Gwangju Institute of Science and Technology in Korea have developed a scheme for AI-assisted design of FRC structures with spatially varying optimal fiber sizes, making FRCs more lightweight without compromising their mechanical strength and stiffness, which will reduce the energy consumption of cars, aircrafts, and other vehicles.

Ramathasan Thevamaran, a UW–Madison assistant professor of engineering physics who led the research, said the nanofibre mats exhibit protective properties that far surpass other material systems at much lighter weight.

Thevamaran and his collaborators detailed the advance in a paper published in ACS Nano.