Basketball shoes on a gym floor, bicycle brakes in need of a tune-up, or the squeal of tires are everyday examples of squeaking sounds. Such sounds have long been attributed to stick-slip friction, or ...

The acoustic properties of an ultracold fermion gas have been measured either side of the superfluid transition temperature in an experiment that has been described as “near perfect” and “beautiful”.

A team at New York University has discovered a new form of time crystal that hovers using sound waves. Unlike ordinary matter, these crystals seem to behave in ways that don’t align with Newton’s ...