Scientists at Griffith University’s Centre for Quantum Dynamics have a new explanation on why time moves forward, but not backwards and this could challenge some of the long-held presumptions of time and the evolution of the universe.

Joan Vaccaro, who is an associate professor and lead researcher of the study said that the “incessant unfolding of the universe over time is an elemental part of Nature.” The claim, which is based on her calculations, says that the laws of physics do not have to distinguish between time and space.

Vaccaro thinks the answer to why do not experience time in the same way as space, lies within a special class of quantum phenomena, suggesting that time may have a deeper origin due to the a difference between the two different directions of time, the future and the past.

“If you want to know where the universe came from and where it’s going, you need to know about time,” said Vaccaro in a news release. “Experiments on subatomic particles over the past 50 years ago show that Nature doesn’t treat both directions of time equally. In particular, subatomic particles called K and B mesons behave slightly differently depending on the direction of time. When this subtle behaviour is included in a model of the universe, what we see is the universe changing from being fixed at one moment in time to continuously evolving.”

Why time moves forward, not backwards
Subatomic particles called K and B mesons behave slightly differently depending on the direction of time. Joan Vaccaro thinks that these subatomic particles could provide some interesting information on why the universe moves forwards in time. [Lassedesignen/Shutterstock]
“In other words, the subtle behaviour appears to be responsible for making the universe move forwards in time. Understanding how time evolution comes about in this way opens up a whole new view on the fundamental nature of time itself. It may even help us to better understand bizarre ideas such as travelling back in time.”

According to the paper titled “Quantum Asymmetry Between Time and Space,” published in the Proceedings of the Royal Society A, there exists an asymmetry between time and space in a sense that physical systems evolve over time, but there is no corresponding ubiquitous translation over space.

Vaccaro claimed that this asymmetry which is long presumed to be elemental is represented by equations of motion and laws of conservation, which operate differently over time and space. However, she used a “sum-over-paths formalism” to demonstrate the possibility of a time and space symmetry.

“In the connection between time and space, space is easier to understand because it’s simply there. But time is forever forcing us towards the future,” said Vaccaro. “Yet while we are indeed moving forward in time, there is also always some movement backwards, a kind of jiggling effect, and it is this movement I want to measure using these K and B mesons.”

Voccaro also discovered that time and space behaved identically later after she reworked the equations of quantum mechanics (without considering the conservation of mass as a given condition of the universe). IFLScience reports that her reworked equations evolved into the ones that describe the universe once violation of symmetries are permitted and the law of conservation of mass comes directly from this theory. Vaccaro said the study provides a solution to the origin of dynamics.