Researchers at the University of Cambridge used quantum entanglement to simulate a scenario similar to backward time travel. This allows previous procedures to be changed retrospectively, which may improve current outcomes.
Physicists have shown that virtual time travel simulation models can solve experimental problems that seemed impossible to solve using standard physics.
If gamblers, investors, and quantitative researchers could bend the arrow of time, their profits would be much higher, resulting in much better results.
“We are not proposing a time-traveling machine, we are proposing to explore the basics of quantum mechanics.” — David Arvidsson-Shukur
Researchers at the University of Cambridge have shown that by manipulating entanglement – a feature of quantum theory that makes particles intrinsically connected – they can simulate what would happen if someone could travel back in time. So gamblers, investors, and quantitative experimenters can, in some cases, retroactively change their past actions and improve their results in the present.
Simulation and time loop
Whether particles can travel backwards in time is a controversial topic among physicists, although scientists have done so previously Simulation of how this space-time loop would behave if it really existed. By linking their new theory to quantum metrology, which uses quantum theory to make highly sensitive measurements, the Cambridge team has shown that entanglement can solve seemingly impossible problems. The study was published Oct. 12 in the journal Physical review letter.
“Imagine you want to send a gift to someone: you have to send it on the first day to ensure it arrives on the third day,” said lead author David Arvidsson-Shukur, from the Hitachi laboratory in Cambridge. “However, you only receive the person’s wish list on the second day. Therefore, in this chronological scenario, it is impossible for you to know in advance what they want as a gift and ensure that you send the right gift.
“Now imagine that you can change what you send on day one with the information from the wish list you receive on day two. Our simulation uses quantum entanglement manipulation to show how you can retroactively change your past actions to ensure the final outcome is what you want. want to.
Understanding quantum entanglement
These simulations rely on quantum entanglement, which consists of the strong connections that quantum particles can have, and that classical particles – governed by everyday physics – cannot have.
What’s unique about quantum physics is that if two particles are close enough to each other to interact, they can remain connected even though they are separated. This is essentially quantitative statistics utilizing continuum particles to perform calculations that are too complex for classical computers.
“In our proposal, an experimental scientist involved two particles,” said co-author Nicole Younger Halpern, a researcher at the National Institute of Standards and Technology (NIST) and the University of Maryland. “The first particles are then sent to be used in experiments. After obtaining new information, the experimenter manipulates the second particle to effectively change the previous state of the first particle, thereby changing the outcome of the experiment.
“The effect is amazing, but it only happens once out of four times!” Arvidsson-Shukur said. In other words, the probability of simulation failure is 75%. But the good news is that you know when you have failed. If we stick to our gift analogy, one out of four times the gift will be what you want (a pair of trousers, for example), and other times it will be a pair of trousers but the wrong size, or the wrong color, or it will be a jacket.”
Practical applications and limitations
To give technical relevance to their models, theorists link them to the science of quantitative measurement. In a typical quantification experiment, photons—tiny particles of light—are shone onto a sample of interest and then recorded using a special type of camera. For this experiment to be effective, the photons must be prepared in a certain way before they reach the sample. The researchers have shown that although they learned how to better prepare photons only after they reached the sample, they can use time-travel simulations to change the original photons retroactively.
To deal with the high probability of failure, theorists propose sending large numbers of entangled photons, knowing that some of them will eventually carry correct, up-to-date information. They then use filters to ensure the right photons enter the camera, while the filters reject other “bad” photons.
“Think about our earlier analogy about rewards,” says co-author Aidan McConnell, who carried out the research while completing his master’s degree at the Cavendish Laboratory in Cambridge, and is now a PhD student at ETH, Zurich. “Suppose sending gifts is not expensive, and we can send several packages on the first day. By the second day we know which gifts we should send. By the time the package arrives on the third day, one of every four gifts will be received. right, and we chose him.” By notifying recipients of which shipments need to be disposed of.
“That we needed to use a candidate for our trial to be successful is actually very reassuring,” Arvidsson-Shukur said. “The world would be very strange if time travel simulations worked every time. Relativity and all the theories that form the basis of our understanding of the universe will no longer exist.”
“We are not proposing a time travel machine, but rather diving into the basics of quantum mechanics. This simulation does not allow you to go back and change the past, but it allows you to create a better tomorrow by fixing yesterday’s problems today.” .”
Reference: “Non-classical features in metrology generated by closed-time virtual curve quantum simulation” by David R.M. Arvidsson-Shukur, Aidan G. McConnell, and Nicole Yunger Halpern, 12 October 2023, Physical review letter.
doi: 10.1103/PhysRevLett.131.150202
This work was supported by the American Sweden Foundation, the Lars Herta Memorial Foundation, Girton College, and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI).
2023-10-21 21:35:29
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