One of the most fundamental elements of the universe, time may not be real but an illusion created by quantum physics, suggests a new study.
The groundbreaking study shows time emerging from quantum entanglement- a weird connection between two very distinct particles.
Time has always been a tricky subject to define in Physics due to its inconsistent behaviour between the best universe theories available. Time has always led to a dead-end, preventing researchers from explaining all of the physics in the universe, what is called a “theory of everything.”
But the new study, published on May 10 in the journal Physical Review A, brings hope in solving this deadlock.
“There exists a way to introduce time which is consistent with both classical laws 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 problem of time
There are two theories on time- one in quantum mechanics and one illustrated by Einstein’s theory of general relativity.
In quantum mechanics, time is a fixed phenomenon with a unidirectional flow from the past to the present. It remains external from the ever-changing quantum systems it measures and can be seen only by observing changes to outside entities, such as the hands of a clock.
But to Einstein’s theory of general relativity- time is interwoven with space and can be warped and dilated at high speeds or in the presence of gravity.
This leaves our two best theories of reality at a fundamental impasse. Without its resolution, a coherent theory of everything remains out of reach.
“It seems there is a serious inconsistency in quantum theory,” Coppo said. “This is what we call the problem of time.”
Probable solution
To resolve this problem, the researchers turned to a theory called the Page and Wootters mechanism. First proposed in 1983, the theory suggests that time emerges for one object through its quantum entanglement with another acting 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 this theory to two entangled but noninteracting 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 by the Schrödinger equation.
They repeated their calculations twice, assuming first that the magnet clock and then the harmonic oscillator were macroscopic (larger) objects. Their equations simplified, suggesting that time’s flow is a consequence of entanglement even for objects on large scales.
“We strongly believe that the correct and logical direction is to start from quantum physics and understand how to reach classical physics, not the other way around,” Coppo said.
(With inputs from agencies)