Grasp the pulse of the world: scientists have hit upon the solution to 150-year-old riddle

The idea that light has a pulse is not new, but the exact nature of how light interacts with matter, remained a mystery for almost 150 years. A new study recently published in Nature Communications, may have uncovered a key to one of the darkest secrets of the world.

Johannes Kepler, the famous German astronomer and mathematician, first suggested in 1619, that the pressure of sunlight could be the reason that a comet's tail always points away from the Sun, says study co-author and a professor of engineering at UBC Okanagan Kenneth Chow. Only in 1873, James Clerk Maxwell predicted that this radionuclear pressure is related to the momentum, which is in itself the electromagnetic fields of light.

Grasp the pulse of the world: scientists have hit upon the solution to 150-year-old riddle

"Until now we have not defined how this impulse is transformed into force and motion," says Chow. "As the momentum carried by light is very small, we did not have enough sensitivity for its hardware detection."

Now technology appeared Chow, and his international research team from Slovenia and Brazil, sheds light on this mystery. To measure the extremely weak interactions between the photons of light, the team built a special mirror, equipped with acoustic sensors and thermal protection to reduce noise and background noise to a minimum. Then they shot laser pulses in a mirror and using sonic sensors for detecting elastic waves at the mirror surface, like ripples in a pond.

A pulse of light: how to find?

"We can not directly measure the momentum of the photons, so our approach was to discover its influence on the mirror," listening to "the wave that passes through it," says Chow. "We were able to trace the features of these waves to pulse, which is the pulse of light that finally opens the door for the simulation of the light pulse in the materials."

This discovery is important for understanding the world, but Chow also notes the possible practical application of light pressure - for example, in solar sails.

It turns out, the light is not so weightless? Tell us what you think about it in our Telegram chat.