Optical darkness travels faster than light, scientists say

It is a commonly accepted idea that nothing can travel faster than the speed of light, but this is not entirely accurate. Albert Einstein stated in 1905 that information cannot travel faster than light; however, something that is massless and devoid of information could potentially exceed this cosmic speed limit—such as “darkness” itself.

A team of international scientists, led by researchers at the Technion Institute of Technology, did not measure “darkness” or the absence of photons directly. Instead, they focused on “dark points” within light waves.

You can think of these points as tiny holes in a wave structure where the amplitude drops to zero. They are often referred to as “zero points” or “null points,” representing complete darkness embedded within a light field.

The authors note that these formations, known as vortices, produce a phenomenon they liken to a river vortex overcoming the water’s current, which makes their speed technically superluminal. The findings of this study were featured in the journal Nature.

“Theory has long predicted that optical singularities can exhibit superluminal motion, particularly at moments close to their creation or annihilation,” the authors wrote.

To demonstrate that darkness can travel faster than light, scientists developed a unique microscopy system. This system combined an advanced laser setup with a specialized opto-mechanical component, allowing researchers to collect data with high precision in both space and time.

The experiment utilized a thin flake of hexagonal boron nitride, a material that allows light to convert into “light-sound waves,” which are known as polaritons. This quasiparticle is essentially a hybrid of light and matter, and it significantly slows down the speed of light by about 100 times compared to its speed in a vacuum.

It’s in this specific state that “dark point” vortices can be seen surpassing the speed of light.