Can Light Move Faster Than speed of Light?

Something very strange was caught on camera last year. A research team at the Technion — Israel Institute of Technology filmed tiny points inside a beam of light moving faster than the speed of light — roughly 1.04 times faster, to be exact. The material they used was a very thin crystal called hexagonal boron nitride. Their findings, shared in a new preprint, show that certain features of light can reach speeds that seem to break the rules — without actually breaking any rules at all.

What Are Phase Singularities — and Why Do They Matter?

You have probably seen what happens when two water waves cross each other. At certain points they add up, at others they cancel out. In a light beam, something similar happens — and at the exact spots where the light waves fully cancel, you get what scientists call a phase singularity. A point of complete darkness sitting right inside a beam of light. These points are not random. They carry a tiny amount of what physicists call topological charge — a kind of built-in twist in the light around them. Think of it like a whirlpool in water. The water around it spins, and the centre is still.

These singularities show up everywhere in wave physics — in sound, in quantum fluids, even in the magnetic fields inside superconductors. Scientists have studied them for decades. What made them hard to study in detail was speed. They appear and disappear in fractions of a second, at scales far smaller than the wavelength of light itself. Watching them required tools that simply did not exist — until now.

The Problem: No One Could Film Them Fast Enough

Watching a phase singularity move is a bit like trying to photograph a hummingbird's wings with a regular camera. You need something much faster than what most labs have. The events the Technion team wanted to film happen in femtoseconds — that is one millionth of one billionth of a second. And the singularities themselves are smaller than the wavelength of the light creating them.

Earlier studies could measure where singularities were located at a single moment in time, or get rough statistics about their behaviour across many frames. But tracking them closely — watching one singularity speed up, slam into another, and disappear — had never been done. The data just was not there. Theory had predicted for years that singularities should accelerate to unbounded speeds right before they collide and cancel each other out. No experiment had actually shown it happening. That gap is what this team set out to close.

How Did the Team Actually Capture Faster-Than-Light Motion?

The key was combining two things: a very unusual material and a very unusual microscope. The material — hexagonal boron nitride — has a rare property. When you shine infrared light on it, the light locks onto the vibrations inside the crystal and travels together with them as a combined wave, called a phonon polariton. These waves move much more slowly than normal light — about 100 times slower than light in open air. That slowness turns out to be critical, as we will get to in a moment.

The microscope was an ultrafast transmission electron microscope, or UTEM, based at the Technion. Instead of using light to take images — which would be far too slow — it fires tiny pulses of electrons at the sample. By carefully timing those pulses with the laser that creates the light waves, the team could take 285 snapshots across a period of about 800 femtoseconds. Each snapshot captured both the position and the phase of the singularities. Together, they added up to something close to a slow-motion film of events happening faster than almost anything else in nature. The average measured speed of the singularities came out at 1.04 times the speed of light — slightly above c, the universal speed limit. And 29% of all singularities measured were moving even faster than that.

What This Means for Future Light-Based Technology

So why does it matter that some points in a light field can move faster than light, if no information travels with them? A few reasons, and they are fairly concrete. First, the techniques developed here — the combination of ultrafast electron microscopy with phase-resolved imaging at this level of precision — open up a new way to study how light behaves inside very thin materials. That matters for anyone building next-generation optical chips, sensors, or communication devices based on 2D materials like boron nitride or graphene.

Second, these singularities carry what is called topological charge — a property that is very stable and hard to accidentally destroy. That stability makes them attractive for storing and moving information in future light-based computing systems. Knowing exactly how they move, speed up, and disappear gives engineers a much clearer picture of how to work with them. And third, the statistical framework the team built to analyse hundreds of singularities at once — tracking both their positions and their speeds together — is a tool that other labs can now use on completely different materials and systems.

What the Team Cannot Fully Explain Yet

The team is careful to note that the maximum speed they could actually measure was limited by their microscope — not by the material or the physics. Faster singularities existed in their data, but the instrument could not capture them clearly enough to count. That means the true upper range of singularity speeds in this system is still unknown. There is also an open question about what happens in materials with stronger light-matter interactions, or in systems that do not follow the Gaussian random wave model the team used as their theoretical framework.

Extending this approach to other 2D materials — graphene, molybdenum disulfide, and their combinations — is the obvious next step. Each of those materials has different optical properties, and singularities in those systems may behave in ways that current theory does not yet predict. The imaging platform the team built is ready. What it will find next is the open question worth watching.

• No rules were broken — singularities carry no energy or information, so their speed has no upper limit under the laws of physics; going faster than light is allowed for them.
• Slow light helps — the very slow group velocity of waves in hexagonal boron nitride is what pushed so many singularities past the speed of light in this experiment.
• A new imaging tool exists — the ultrafast electron microscopy method used here can now be applied to other materials, giving scientists a way to study fast wave dynamics that was not available before.

"Our findings enable probing topological defect dynamics at previously unattainable timescales, deepening our understanding of phase-singularity universality and suggesting phenomena of ultrafast information flow in polaritonic media." — Bucher, Gorlach et al., arXiv, 2025.