Did scientists just prove time is an illusion? ‘Mini-universe’ experiment explained

Have you ever thought about the origin of time? There is a prevailing and long-held view that time comes to existence with the Big Bang. Despite its existence, this topic is debatable as one side argues that time is just an illusion and the other side negates the illusory nature of time based on realistic dynamics.

For instance, British physicist Julian Barbour argues that time as we experience it is just a “cognitive illusion” like a flowing river carrying us from past to future.

Many other physicists and philosophers strongly disagree with the idea that time is illusory based on providing the evidence related to entropy and thermodynamics. Even some theories suggest that the universe is static so in this case time should not exist at all.

To solve the problem of time, the scientists at the University of Birmingham have created a “mini universe” that can measure the passage of time without relying on a conventional clock.

In the research published in the journal Physical Review Research, the researchers successfully measured the passage of time without an external clock by relying solely on the internal dynamics of a quantum system.

What is the 'mini-universe' experiment?

In the experiment, the physicist created an isolated and miniature universe using 24,000 ultracold atoms, a unique state of matter that only forms near absolute zero. To simulate the “Big Bang” and “Big Crunch”, they split the atoms into bright and dark regions.

The bright regions experienced cycles of expansion and contractions, acting as a big bang and big crunch.

To measure time, the team did not use conventional and external clocks, instead they built “entropic time,” measuring the randomness or disorder in the system.

According to findings, time arises from changes in entropy as atoms move between these two regions and the movement of these atoms define the speed of time. Once the particles stop moving or changing, time ceases to exist for that system.

"Time was speeding up or slowing down, or even stopping, depending on what the system was doing," Giovanni Barontini, lead author, said.

He refers to this concept as “entropic time,” flowing in one consistent direction, producing a clear "arrow of time" and is variable.

Is time an illusion?

He further discovered that both time and its unidirectional flow may come from the same source: an observer’s choice to discard information.

By deliberately choosing to ignore the dark region of the system, Barontini relinquished knowledge about half of it.

So when he ignored the dark region, it means he created the flow of time in the observable half, showing that time is not based on hard-core comic rules. In fact it is an illusion that comes from the “changes within a system rather than as the external 'ticking clock' we think of as time.”

"This study provides the first controlled experimental evidence that 'time' can be defined by changes within a system rather than as the external 'ticking clock' we think of as time. It offers new insight into the nature of time in quantum gravity that could be used to describe dynamics just as effectively as conventional time."