A team of New York University researchers announced in early February 2026 that they had created “levitating” time crystals, tiny particles suspended by sound waves that appear to defy Newton’s third law of motion The discovery sits at the intersection of classical physics and a concept once confined to quantum theory, raising sharp questions about what counts as breaking the rules versus bending them in clever new ways. Far from a lab curiosity, the work connects to a growing body of research suggesting that nonreciprocal forces in driven systems could reshape how scientists think about self-sustaining motion in everything from soft robotics to biological rhythms.
Sound Waves, Levitating Particles, and a Broken Law
Newton’s third law states that for every action of an object, there is an equal and opposite reaction. The NYU experiment challenges that principle at the level of effective forces between particles. Two small objects are suspended in an acoustic standing wave, where they interact by exchanging scattered sound. As described in the team’s preprint, if the two particles scatter sound differently, the force that one exerts on the other is not matched by an equal return force. That asymmetry, known as nonreciprocal interaction, enables sustained oscillations that persist even against the drag of the surrounding air. The result is a system that keeps moving in a repeating pattern without any external clock telling it when to tick.
“Sound waves exert forces on particles, just like waves on the surface of a pond can exert forces on a floating leaf,” explains Mor, one of the researchers, according to NYU. What makes this system remarkable is its simplicity: it is classical and macroscopic, meaning no exotic quantum hardware is needed. The particles are large enough to see, and the acoustic setup is straightforward enough that the researchers describe the time crystal as something you could hold in your hand. That accessibility marks a significant departure from earlier time crystal demonstrations, which typically required ultracold atoms or carefully tuned quantum systems far removed from everyday experience.
What “Breaking Newton’s Rules” Actually Means
The headline claim that these particles defy Newton’s third law deserves careful framing. At the most fundamental level, Newton’s laws remain intact. The apparent violation occurs because the system is driven: energy continuously flows in through the acoustic field, and the effective interactions between the particles, not the underlying physics, become asymmetric. A theoretical framework published on arXiv in 2021 showed that in driven soft matter, action and reaction symmetry can be broken at the level of effective forces, leading to qualitatively new mechanical behavior. The particles are not conjuring energy from nothing. Instead, the acoustic field acts as a hidden third partner, absorbing and redistributing momentum so that the two visible particles appear to violate the familiar equal-and-opposite rule.
This distinction matters because it separates genuine new physics from a misunderstanding of boundary conditions. The nonreciprocal mechanics described in the soft matter literature show that when energy is pumped into a system from outside, the internal forces between components can look lopsided without any fundamental law being overturned. The NYU time crystal is a vivid, tangible example of that principle. It does not invalidate Newton so much as demonstrate that Newton’s third law, as typically stated for isolated systems, needs careful reinterpretation when external drives are present. For readers unfamiliar with the nuance, the practical takeaway is this: the particles really do behave in ways that classical intuition would call impossible, but the explanation lies in the energy source powering the system rather than in a flaw in three-century-old physics.
Time Crystals Beyond Sound: Visible and Photonic Variants
The NYU acoustic experiment is not the only recent advance in time crystal research. A separate line of work has produced time-crystalline behavior in liquid crystal systems that is observable under a microscope and possibly even to the naked eye, according to a peer-reviewed paper by Zhao and Smalyukh in Nature Materials. That study represents a different physical platform but shares the same core idea: a system whose state repeats in time with a period that is not simply inherited from an external driver. The liquid crystal approach and the acoustic levitation approach together suggest that time-crystalline behavior is not a narrow quantum oddity but a broad phenomenon accessible across multiple material systems and length scales.
Meanwhile, researchers working in photonics have extended the time crystal concept in yet another direction. A recent paper in Nature Communications examines the quantum electrodynamics of photonic time crystals, where the defining feature is a time-periodic modulation of a material’s optical properties rather than spatial periodicity. These photonic systems carry explicit quantum implications and could eventually influence how light is controlled in optical circuits. The breadth of these parallel efforts, spanning acoustics, liquid crystals, and photonics, indicates that the time crystal concept has moved well past its origins in theoretical physics and into a phase of rapid experimental diversification. As a recent news feature emphasized, newer demonstrations of time crystals relate directly to early theoretical constraints that once made the idea seem impossible, underscoring how quickly the field has matured.
From Lab Trick to Potential Technology
The most provocative implication of the NYU work is not the headline about Newton but the connection to biology. According to the university’s description of the experiment, these levitating particles behave as self-sustained oscillators whose timing emerges from internal interactions rather than from a metronome-like external drive. That self-organized rhythm invites comparison to biological clocks, from the beating of cilia and flagella to the circadian cycles that govern sleep and metabolism. In many living systems, energy is constantly pumped in through chemical reactions, and internal components exchange forces in ways that are effectively nonreciprocal. The acoustic time crystal therefore offers a stripped-down mechanical analog for probing how robust timing can arise in noisy, driven environments, an idea that resonates with long-standing questions in chronobiology and cellular biophysics.
Beyond biology, the broader field of nonreciprocal mechanics hints at technological applications where motion or oscillations are sustained and steered without conventional feedback controllers. Because the NYU setup uses macroscopic particles and accessible sound fields, it could serve as a testbed for designing self-oscillating elements in soft robots or adaptive materials that harness environmental energy. Insights from driven soft matter theory, such as those outlined in the 2021 analysis of active systems, suggest that tuning nonreciprocal couplings could allow engineers to program collective motion, directional transport, or mechanical memory directly into the structure of materials. In that sense, time crystals are not just curiosities that tick on their own; they are prototypes for devices that might one day manage energy and information in fundamentally new ways.
A Rapidly Expanding Research Landscape
The speed with which time crystals have moved from theoretical speculation to tabletop demonstrations reflects a broader transformation in condensed matter and materials research. Just a decade ago, the notion of a system that spontaneously breaks time-translation symmetry was often framed as a thought experiment. Now, multiple experimental platforms (from levitated particles to liquid crystals and photonic media) are being explored in parallel, each revealing different facets of the underlying physics. Coverage by science journalists such as Elizabeth Gibney has highlighted how quickly experimentalists have learned to navigate the theoretical constraints that once seemed prohibitive, often by embracing driven, dissipative conditions rather than trying to approximate perfectly isolated systems.
This diversification is visible across the broader ecosystem of physics and materials journals, where time crystals now appear alongside topics like metamaterials, active matter, and topological phases. A glance at the index of recent Nature content shows time-dependent phases of matter cropping up in contexts ranging from quantum information to photonic engineering. The NYU levitating time crystals fit neatly into this trend: they are classical yet exotic, visually striking yet conceptually subtle, and they blur the line between fundamental tests of physical law and blueprints for future devices. As researchers refine control over nonreciprocal forces and driven oscillations, the question is shifting from whether time crystals can exist to how their peculiar rhythms can be harnessed, whether to model the beating heart of a cell, stabilize delicate quantum states, or build machines that keep their own time in a world that is anything but static.
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*This article was researched with the help of AI, with human editors creating the final content.
