Time may not be a fundamental element of the universe, but rather an illusion arising from quantum entanglement, a new study suggests.
Time is a vexing problem for physicists; its inconsistent behavior among our best theories of the universe contributes to the impasse that prevents researchers from finding a “theory of everything,” or a framework to explain all the physics in the universe.
But in a new study, researchers suggest they may have found the key to solving this problem: by making time a consequence Quantum entanglement, a strange connection between two distant particles. The team published their findings May 10 in the journal Physical overview A.
“There is a way to introduce time that is consistent with both classical and quantum laws and is a manifestation of entanglement,” first author Alessandro Coppo, a physicist at the National Research Council of Italy, told Live Science. “The correlation between the clock and the system creates time, which is an essential component of our lives.”
It’s time
in quantum mechanics, our best theory of the microscopic world, time is a fixed phenomenon—an inexorable, one-way flow from the past to the present. It remains external to the bizarre and ever-changing quantum systems it measures, and can only be seen by observing changes in external entities such as the hands of a clock.
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Yet according to Einstein’s theory general theory of relativity — which describes larger objects like our bodies, stars and galaxies — time is woven through space and can warp and dilate at high speeds or in the presence of gravity. This leaves our two best theories of reality at an impasse. Without solving it, a coherent theory of everything remains out of reach.
“There seems to be a serious inconsistency in quantum theory,” Coppo said. “We call it the problem of time.
To solve this problem, the researchers turned to a theory called the Page and Wootters mechanism. This theory was first proposed in 1983 and posits that time for one object appears through it Quantum entanglement with another functioning as a clock. For an unentangled system, on the other hand, time does not exist and the system perceives the universe as frozen and unchanging.
By applying Page and Wootters’ mechanism to two entangled but non-interacting theoretical quantum states—one a vibrating harmonic oscillator and the other a set of tiny magnets acting as a clock—the physicists found that their system could be perfectly described The Schrödinger equation, which predicts the behavior of quantum objects. Instead of time, however, their version of the famous equation ran according to the states of small magnets acting as clocks.
This knowledge is not new, but the team’s next step was. They repeated their calculations twice, first assuming that the magnetic clock and then the harmonic oscillator were macroscopic (larger) objects. Their equations simplified to those for classical physics, suggesting that the flow of time is a consequence of entanglement even for objects on large scales.
“We strongly believe that the right and logical direction is to start from quantum physics and understand how to reach classical physics, not the other way around,” said Coppo.
Other physicists have expressed caution. Although Page and Wootters found the mechanism a fascinating idea for the quantum origin of time, they said it had yet to produce anything testable.
“Yes, it is mathematically consistent to think of universal time as an entanglement between quantum fields and quantum states of 3D space,” Vlatko Vedral, a professor of quantum information science at the University of Oxford who was not involved in the work, told Live Science. “However, no one knows if anything new or fruitful will emerge from this picture – such as modifications of quantum physics and general relativity, and corresponding experimental tests.”
Despite these doubts, building sound theories of time from quantum mechanics may be a promising place to start—if they can be shaped to fit experiments.
“Maybe there’s something about entanglement that plays a part,” Adam Frank, a theoretical physicist at the University of Rochester in New York who was not involved in the study, told Live Science. “Perhaps the only way to understand time is not from some God’s-eye perspective, but from within, from the perspective of asking what it is about life that manifests such an appearance of the world.”