Physicists used ‘dark photons’ in an effort to rewrite physics in 2025

This year, a core tenet of quantum theory was threatened when a team of researchers put forward a radical new interpretation of an experiment about the nature of light.

The new work centered on the double-slit experiment, which was first performed in 1801 by physicist Thomas Young, who used it to confirm that light acts as a wave. Classically, a particle can never be a wave, and vice versa, but in the quantum realm the two are not mutually exclusive. In fact, all quantum objects have what is called wave-particle duality.

For decades, light seemed to be a prime example of this, with experiments showing that it sometimes behaves like a particle called a photon and sometimes like a wave, producing effects like those seen by Young. But at the beginning of this year Celso Villas-Boas from the Federal University of São Carlos in Brazil and his colleagues proposed an interpretation of the double-slit experiment that includes only photonswhich effectively eliminates the need for the wavy part of the duality of light.

After New scientist reported the study, the team behind it was contacted by many colleagues who were interested in the work, which has since been widely cited, says Villas-Boas. One YouTube video about it has been viewed more than 700,000 times. “I've been invited to give talks about it in Japan, Spain, here in Brazil and many other places,” he says.

In the classic double-slit experiment, an opaque barrier with two narrow adjacent slits is placed between the screen and the light source. Light passes through the slits and hits the screen, which forms a pattern of bright and dark vertical stripes known as classical interference. This is usually explained by the fact that light waves pass through two slits and collide with each other on the screen.

The researchers abandoned this idea and turned to so-called dark states of photons, special quantum states that do not illuminate the screen because they are unable to interact with any other particle. Since these states explained the dark streaks, there was no longer any need to summon light waves.

This is a marked departure from the most common view of light in quantum physics. “Many professors have told me, 'You're touching on one of the most fundamental things in my life, I taught interference from a book from the beginning, and now you're saying everything I taught is wrong,'” Villas-Boas says. He says some of his colleagues have adopted the new view. Others remained, if not outright skeptical, then cautiously intrigued, since New scientistThe report was confirmed when the study first became public.

And since then, Villas-Boas has been busy exploring several new consequences of photon dark states. For example, mathematical analysis by him and his colleagues showed that thermal radiation, such as light coming from the Sun or stars, can have dark states that carry a significant portion of their energy, but because they do not interact with other objects, this energy is in some sense hidden. This can be verified in experiments that put atoms into cavities where their interaction with light can be precisely monitored,” says Villas-Boas.

He says his team's new interpretation of interference also makes it possible to understand seemingly impossible phenomena, such as the interference of waves even when they don't directly overlap, or the interference between mechanical and electromagnetic waves. In any case, abandoning the wave model in favor of bright and dark states of photons opens up new possibilities. Villas-Boas could even imagine using some of these discoveries to create new types of light switches or devices that transparent to certain types of light.

In his view, all this work is related to a fundamental truth of quantum physics: it is impossible to discuss quantum objects without describing how they interact with detectors and other devices. measuring instrumentsincluding darkness. “In my opinion, this is not new. This is what quantum mechanics already tells us,” says Villas-Boas.