First time 'capturing' light in virtual time

Physicists at the University of Maryland (USA) have just achieved an unprecedented scientific milestone: observing light as it moves in 'imaginary time', a mathematical concept that seems unreal.

Observing the movement of light in both real space and "virtual time" will open up many prospects for practical applications in modern human life - Illustration: NASA

Normally, when light passes through a transparent material, it does not travel as freely as it would in a vacuum. The complex network of electromagnetic fields within the material slows down each photon, delaying the journey of the entire light beam.

This phenomenon helps scientists understand how light interacts with the microstructure of materials, thereby exploring its physical properties.

From virtual to real

Part of the mathematical models that describe this phenomenon often use numbers called imaginary numbers. These numbers have no real value in everyday life and are often considered purely mathematical tools. The new experiment demonstrates that these seemingly only-on-paper numbers can actually manifest as completely measurable physical phenomena.

In a study published in Physical Review Letters , one of the most prestigious scientific journals in the field of physics, a team of physicists Isabella Giovannelli and Steven Anlage said they used microwaves, a form of light outside the visible range, and transmitted it through a closed loop of coaxial cable. This device simulates a controlled environment to study the propagation of light pulses through materials.

By measuring the tiny frequency fluctuations of the microwaves as they passed through the system, they discovered that the frequency shifts were not random, but were the physical manifestation of imaginary numbers in the equation.

This shows that the concept of imaginary time is not just a mathematical fantasy but actually exists and affects the propagation of light.

Dr Anlage said his team had discovered a previously overlooked degree of freedom in light waves, allowing a phenomenon once considered "virtual" to be explained by entirely real factors.

Remarkably, light pulses in this medium can temporarily move faster than the photons that make them up. This may sound paradoxical, but it is a logical consequence of the influence of the medium and the wave structure.

Many prospects for practical applications

The success of this experiment is not simply a step forward in the field of theoretical physics. The observation of light in a state called "imaginary time" also opens up many prospects for practical applications in modern life.

As humans better understand how electromagnetic waves, from light to microwaves, move and change as they pass through matter, we can optimize many of the technologies that rely on them.

For example, in the field of wireless communications, this new knowledge can help improve the speed and accuracy of signal transmission. With radar and sensor systems, it can contribute to increased sensitivity and reduced interference, thereby improving efficiency in fields such as aviation, military , and automation.

Particularly in the emerging world of quantum computing, where every interaction depends on the behavior of microscopic particles like photons, a deeper understanding of how light behaves could be key to designing more powerful and stable computing devices in the future.

In other words, from a phenomenon once considered completely abstract, virtual time is now gradually becoming a useful part of the real technological world.

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MINH HAI

Source: https://tuoitre.vn/lan-dau-bat-duoc-anh-sang-trong-thoi-gian-ao-20250630214758668.htm