Japanese
“/>. Sending the spacecraft to another solar system, located in our galaxy. And although a giant array of lasers in principle can send light ships the size of a microchip to another Japanese star at a speed of 20% of the speed of light, it is unclear how these devices, deprived of energy sources, will transmit messages to us through vast spaces. Olivier Manuel believes that he has found a way out:
This is a bold assumption, but is it possible to use quantum entanglement to transmit messages?
It is worth considering this possibility. Let’s take a look at this idea.
Imagine that you have two coins, each of which can fall out with an eagle or a bar. You have one, another, and we are very far apart. We toss them up, catch them, and put them on the table. When we look at the coin, we expect that each of us has a 50/50 chance to open the eagle and 50/50 to the edge. In the ordinary, uninhabited universe, our results with you will not depend on each other. If you get an eagle, I still have a 50/50 chance of getting an eagle or tails. But under special circumstances, the results may be confusing, that is, when you drop an eagle, you can be 100% sure that I have a tailspin – even before I tell you about it. You will know this instantly, even if there are light years between us.
The quantum-mechanical Bell test for particles with half-integer spin
In the quantum Physics does not entangle coins, but individual particles, electrons or photons, and then, for example, each of the photons can have a spin equal to +1 or -1. If you measure the spin of one of them, you can immediately recognize the spin of the other, even if it is half the distance away from the universe. Until you measure the spin of these particles, they will exist in an indeterminate state; But when you measure one, you will immediately recognize the second. On Earth, we conducted an experiment where two entangled photons were divided into many kilometers, and we measured their spins with an interval of less than a few nanoseconds. We found that if one of them turned out to be +1, we knew that the other one was -1 10,000 times faster than the speed of light would allow us to convey this information.
Let’s return to Olivier’s question: is it possible to use this entanglement to transfer messages from a remote stellar system to ours? In principle, yes, if the measurement made at a remote point is taken as one of the forms of communication. But speaking of reports, you most likely mean that you want to learn something about a remote point. You can, for example, keep a particle in an uncertain state, send it to a remote star, and put the task of finding a rocky planet in a habitable zone. If the system finds a planet, the measurement causes the particle to assume the state +1, and if not, the measurement gives the particle a state -1.
Therefore, it seems that the particle on The Earth, when you measure it, will either be in the state -1, which means that the spacecraft has found a rocky planet in the inhabited zone, or in the state +1, which means that the planet is not there. If you know that the measurement has taken place, you should be able to conduct your measurement and immediately know the state of that particle, possibly in many light years from you.
Wave pattern the electrons pass through the two slits. If to measure, through what particular gap the electrons pass, the picture of quantum interference is violated.
A brilliant plan, but it has a problem: entanglement works only if you ask the particle: “What state are you in?” . If you force an entangled particle to accept any state, you will break the confusion, and the measurement on the Earth will not depend on the measurements of the distant star. If you simply measure the state of a remote particle, be it +1 or -1, then your measurement on the Earth will give you -1 or +1, respectively, and you will know the state of the remote star. But if you force a remote particle to accept a state of +1 or -1, it will mean, regardless of the outcome, that your particle on Earth will be in the +1 or -1 state with 50/50 chances.
Experiment with the erasure of the quantum state
This is one of the most incomprehensible properties of quantum physics: entanglement can be used to obtain information about the component of the system, when you know the complete state, and you measure state of the other components, but not for the creation and transmission of information od second part of the confusing system to another. A cunning idea, Olivier, but there is no communication with a speed exceeding light.
The effect of quantum teleportation is confused with travel faster than light. In fact, information is not transmitted faster than light
Quantum entanglement is an amazing property, and it can be used for different purposes, for example, in an ideal lock / key system. But communication faster than light? To understand why this is impossible, one must understand the key property of quantum physics: forcing a part of an intricate system to go to a certain state does not allow you to obtain information about this state by measuring its remaining part. As the well-known statement by Niels Bohr says:
If you were not shocked by quantum mechanics, you just did not understand it yet.
The universe constantly plays with us to the bone, to Einstein’s great chagrin. But nature upsets even our best attempts to cheat in this game. If only all judges with arbitrators were as strict as the laws of quantum physics!
