In a groundbreaking experiment, researchers at New York University have created a new form of time crystal that levitates and oscillates visibly in mid-air — and the device is small enough to hold in your hand. The discovery challenges traditional boundaries between classical and quantum systems, showing that perpetual motion-like behavior can emerge from simple physical setups using sound waves.

Unlike typical crystals that repeat structure in space, time crystals exhibit repeating motion in time, maintaining a stable rhythm without an external clock. The NYU team used an acoustic levitator — a device that traps small particles using standing sound waves — to suspend tiny beads. These beads interact via nonreciprocal sound-mediated forces, allowing them to oscillate continuously even with friction present.

The setup breaks time-translation symmetry, a defining characteristic of time crystals, meaning the system cycles through motion even though the governing sound field remains static. Researchers found that differences in particle size cause unbalanced interactions, enabling the beads to extract energy from the static sound field and sustain their motion without external timing.

Although time crystals were first theorized in quantum systems, this new discovery highlights that similar behavior can arise in classical physics using sound-levitated systems. The findings, published in Physical Review Letters, expand the family of observable time crystals and open up potential avenues for compact oscillators, sensors, and timing devices that don’t rely on traditional clocks.

Experts say the levitating time crystals also offer insights into symmetry and dynamic order, with possible implications for technology and fundamental physics research. While the immediate applications remain exploratory, the experiment shows how human-driven design and observation can reveal surprising phenomena in seemingly simple physical systems, blending innovation with deep scientific inquiry.