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Quantum gravity would reverse the cause and effect

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You’ve probably heard of Schrödinger’s cat, the unfortunate cat in a box, which is at the same time alive and dead until the box is opened to reveal the actual state. Ok, now wrap your mind around Schrödinger’s time-a situation in which an event can be at the same time, the cause and effect of another event.

Such a scenario is inevitable in a theory of quantum gravity, is still obscure field of science that seeks to combine Einstein’s general theory of relativity, the effect of the quantum mechanics. In a new paper, researchers make a mashup of two of your ships are in the vicinity of a giant planet and the mass slows down time. They concluded that the ship would be able to find it in a state in which the causal link is the other way around: An event causing another event, which happened prior to it.

“You can think of to make this kind of a scenario, in which the temporal order and cause-and-effect are, in principle, be recovered or will not be reversed,” said study co-author Igor Pikovski, a physicist at the Center for Quantum Science and Engineering from the Stevens Institute of Technology in New Jersey. “This is what we expect, as soon as we get a full theory of quantum gravity.”

Related: 8 Ways You Can See Einstein’s theory of Relativity in Real Life

The Quantum of time

In the famous Schrodinger’s cat thought-experiment requires an observer to make a box to hold a cat and a radioactive particle, that is, once it’s expired, it will be the death of the unfortunate cat. By the principle of superposition, the cat’s survival or death, it is just as likely to be measured, so it’s only when the box is opened the cat is simultaneously alive and dead. In quantum mechanics, quantum superposition implies that a particle can exist in multiple states at the same time, like Schrödinger’s cat.

The new thought experiment, published Dec. 21 in the journal Nature Communications, combines the principle of superposition, with Einstein’s general theory of relativity. The general theory of relativity says that the mass of a massive object can have the time to slow down. This is a real, measurable, Pikovski, said, an astronaut in orbit around the Earth, it will be the experience of time is only a smidge faster than that of his or her twins on the planet. (This is also the reason why falling into a black hole, it would be a very progressive experience.)

So, as a futuristic spaceship in the area, a massive planet, and the crew would experience time and just a little slower than it would be for the people, in a co-space based on line. Now, throw in a little quantum mechanics, and can you think of a situation in which the planet is superpositioned simultaneously in the near and the far, far away from the two spacecraft.

The period of time that is funny

In this superpositioned scenario of two vessels, the experience of time in multiple time lines, cause-and-effect, it would be able to get wonky. For example, say that the ships will be asked to conduct a training mission, in which they fire at each other and dodging each other’s fire, and knowing full well that the time of the rocket launch and learn more of their positions. If there is not a massive planet in close to mess with the time stream, this is a very simple exercise. On the other hand, when the giant planet is present, and the captain of the ship didn’t slow down the time, the crew is able to escape and will be destroyed.

The planet is in quantum superposition, at the same time, at home and abroad, and it would be impossible to know whether or not the ships could dodge and destroy each other, or if they have to step aside and they need to survive. What’s more, it is a cause-and-effect that can be reversed, Pikovski says. Suppose there are two events, A and B, that are causally related.

“A and B, can influence each other and, in the case of B, while in the other case, B is in a superposition state, Pikovski says. This means that both A and B are at the same time, the cause and effect of each other. Fortunately, the odds in the war, the crews of those imaginary spacecraft, Pikovski told, it would have to be a mathematical way and to analyze each other’s transmissions, in order to confirm that they are in a superpositioned state.

It is clear that in the real world, and the planets move around the galaxy willy-nilly. But it is a thought-experiment, may have practical implications for quantum computing, even without working out a full theory of quantum gravity, Pikovski says. Through the use of superpositions in the computation, a quantum-computing system capable of simultaneously evaluating in a process such as cause and as effect.

“Quantum computers will be able to use it in order to be more efficient to count on it,” he said.

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Originally published on Live Science.

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