The experiment proves that traveling back in time is possible

Scottish scientists create images that move faster than the speed of light and show that images can go back in time.

British genius physicist Lord Rayleigh predicted the reverse transmission of sound waves nearly a century ago. Rayleigh argues that, because the speed of sound is constant, when a music transmitter moves at a speed faster than the speed of sound, the sound waves will propagate towards the music player (instead of spreading out as far as usual. Therefore, the sound seems to be reversed in time orientation.

Illustration of laser scanning on the surface of the Moon.(Photo: Sabine Hossenfelder).

However, researchers have not found a way to easily test the argument of Rayleigh. The sound has a velocity of 1,225 km / h, meaning that to hear a sound clip running 3 seconds backward, a supersonic jet is required at Mach 2 (twice the speed of sound). Then the sound will start playback more than one kilometer away from the listener's position. However, the scattering and absorption of sound waves in the air will make the sound inaudible, and difficult to verify the experiment of Rayleigh.

According to Live Science, physicist Daniele Faccio and colleagues at Heriot-Watt University in Scotland realized if Rayleigh's prediction of sound was correct, light could also be reversed. Light travels at 1.1 billion km / h and the wavelengths of light are very small compared to sound waves. This means, scientists do not need supersonic jets and distance kilometers but can conduct experiments in a normal room.

The biggest problem they have to overcome is that nothing can go faster. To create an object that moves faster than the speed of light, Faccio uses a strange phenomenon called "photonic boom" described in a series of fascinating fantasy experiments.

The secret behind "photonic boom" is the reflection of an object (not that object and photons) that can move faster than light.

You can imagine a laser pen strong enough to point to the Moon. Only by the movement of a wrist in a split second, can you make the projection of the laser pen move from one end of the Moon to the other. While photons from the laser move at normal light speeds, their images on the Moon move much faster.

The projection of an object on a surface may not follow Einstein's equation.(Photo: Engadget).

To catch the reverse time in their experiments, the team shines a stream of light onto the screen and moves that line on the screen at a faster rate than the speed of light. At the same time, they recorded the flow of light moving on the screen with a super high-speed camera, a few picoseconds for a frame.

As a result, the camera captures the flow of light on the screen moving in the opposite direction to how they scan the light stream. Thus, the screen image has gone back in time.

In the second experiment, the team confirmed an even more bizarre phenomenon, known as the pairs of killings. This phenomenon was predicted by Robert Nemiroff, a physicist at Michigan University of Technology, for astronomers in a publication published in arXiv magazine in May 2015.

Faccio and colleagues repeated the experiment on a curved screen. When the speed of light currents exceeds the speed of light, a pair of lines of light moving away from each other is created. When using a screen with different curvature, pairs of light streams move forward, merge again and then cancel each other out.

These findings still contain many mysteries and need more time to analyze and learn. Faccio and colleagues' research was published in the April 15 issue of Science Advances.