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.
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."
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.
