THEORETICAL PHYSICS

THEORETICAL PHYSICS

Julian Berengut

If we found out that the fundamentals of physics are slightly different in different parts of the universe, we could explain once and for all why we’re here.
Fundamental laws govern our universe. But Julian Berengut is challenging whether these laws are constant across space and time, and his research could turn physics on its head.

Why do we exist? And are we alone in the universe?  Dr Julian Berengut’s research may help us solve these age-old questions.

The theoretical physicist uses super-precise measuring devices called atomic clocks to detect whether the fundamental laws of physics, such as gravity and the speed of light, are constant across the universe.

That may not sound relevant to our everyday lives, but the results could help us understand why the universe seems to be perfectly tuned to our existence, and why we haven’t yet discovered life beyond our planet.

“If you change the numbers of these constants even slightly in either direction, life becomes impossible,” explains Berengut. “If we found out that the fundamentals of physics are slightly different in different parts of the universe, we could explain once and for all why we’re here.”

To measure these fundamental laws, Berengut and his team at the UNSW School of Physics needed a clock with unparalleled precision.

“The accuracy is kind of incredible,” he says. “We can now measure to a part in a billion billion. That’s like measuring the distance of Sydney to London down to the nearest atom.”

He found that by measuring the vibrations of highly charged ions, it was possible to create an atomic clock two orders of magnitudes better than the most sensitive clocks – so accurate, in fact, that it can measure the influence of invisible forces.

Using this clock, Berengut will be able to test phenomena like general relativity and dark matter. 

Previously, he worked with a group of astronomers at UNSW and Swinburne University of Technology measuring the fine-structure constant – a physical number that determines how strong electromagnetism is and, therefore, which types of matter can form – in distant galaxies spanning the entire universe. 

Their measurements suggested that the constant has different values in different parts of space, but only very slightly.

The find needs to be verified, but it suggests that our particular corner of the universe may not be that special after all.

“Whether it’s true or not, what we’ve done are the most sensitive tests so far to show that the universe is pretty homogeneous, and that means the ‘little green men’ could be anywhere in our visible universe,” says Berengut. “That’s interesting in itself.” 

As the atomic clock becomes more precise, the team will be able to measure even more tiny fluctuations in the laws of the universe, which means they’ll be able to independently check new astronomical findings in the lab.

“The Standard Model of Physics is not complete,” says Berengut. “What I’d like to do is provide the most accurate measurements possible so that one day someone much smarter than me can come up with a consistent Theory of Everything. I want to understand all the fundamental laws of the universe.”