Quantum communication in space could be possible

What is quantum communication?

When the first theories of quantum physics appeared in the early twentieth century^e century, scientists at the time must have been far from doubting that one day we would talk about quantum communication and the possibility of contacting possible forms of intelligent life. However, physicists seem to have taken a fundamental step by confirming the hypotheses of quantum physics and applying these principles to communication.

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These possibilities would not be possible without the help of mathematics and the use of the concept of quantum entanglement and quantum state transfer. Quantum entanglement is an important concept in quantum physics that has allowed the description of many previously unexplainable phenomena. Quantum entanglement A phenomenon in which two particles are in the same state and share the same quantum properties. When we measure the state of the particle, the other entangled particle automatically takes the same value. This peculiar property exists no matter the distance between the particles in the entangled state.

For example, two photons in the case of quantum entanglement share the same properties. If one of the photons located several thousand light-years away from the other changes its quantum state, the other does so instantly as well.

Also surprising is the idea of ​​quantum state transfer known as quantum teleportation. It is a transfer of the quantum state from one place to another, but without the transfer of matter. This definition makes it possible to quickly realize that the concepts of quantum entanglement and quantum state transfer are closely related.

Remarkably “clean” interstellar space

Physicists from the University of Edinburgh have just described the journey of photons traversing interstellar space without experiencing decoherence. To understand quantum decoherence theory, we must remember what superposition of states means: properties of an atom or quantum system shape its state. However, in quantum physics, a system can be in several states at the same time, it’s a superposition of states.

In 1982, a physicist proposed the idea that there is an interaction between a quantum system and its environment. This means that quantum particles are never isolated from anything that can interact with the system in which they find themselves, ie a measuring device or particles in the air or in interstellar space in the case of photons crossing space. Multiple interactions of quantum particles with the environment lead to rapid destruction of quantum interference. When these quantum interferences are destroyed, the Country Overlays They are eliminated and only simple cases of classical physics remain.

Researchers estimate that photons produced, for example, in stars can easily travel through space over thousands of light years without undergoing quantum decoherence, that is, without encountering obstacles in their path.

Previous research has shown that interstellar space is a clean environment, that is, it contains almost nothing. Some studies estimate that the vacuum of space contains less than a quarter of a proton per cubic meter.

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The possibility of quantitative communication with extraterrestrial civilizations

Mathematics shows that interstellar space is clean enough to allow quantum communications. If there are other intelligent beings in the galaxy or elsewhere on the edge of the universe, they may be able to communicate with us through quantum communication.

These quantum messages sent by an advanced civilization can travel billions of kilometers without going through decoherence due to the void of space that contains almost nothing. Under these conditions, the transmitted message will not suffer any loss in its quantum properties. Arjun Pereira, one of the researchers involved in this study says: “Quantum states are generally very sensitive, because if there is the slightest external interaction, these states can be quickly destroyed.”

Once these quantum messages are sent extraterrestrial, they still need to be decoded to discover their contents. Some researchers believe that light traveling through spacetime, which is thus a quantum system, can be deciphered using quantum computers.

All this at the moment is just speculation and hypothesis, but it opens the way to exciting discoveries that may one day lead to an understanding of what some creatures that live in another part of the universe are telling us!

Also Read: No, Gravity Won’t Be the Reason for Quantum Decoherence

Source: Arjun Berera and Jaime Calderón-Figueroa, “Quantum Communicability Across Interstellar Distances,” Physical Review D, 105, 123033, published June 28, 2022, https://journals.aps.org/prd/abstract/10.1103/PhysRevD.105.123033