The laws of nature may not be as constant as we previously thought

For as long as we’ve had science, scientists have attempted to define our universe. We have certain laws of nature governed by four fundamental forces: gravity, electromagnetism, weak nuclear force and strong nuclear force. These have helped us make sense of our world. But recent research by the University of New South Wales suggests these universal constants may not be as constant as we previously thought. If this is true across the universe, we may need to rewrite some of the fundamental principles guiding physics.

The grand unification theory (GUT) is a model that essentially tries to describe the universe by combing three forces – electromagnetic, strong and weak forces. It’s a bit of a Holy Grail for physicists because, if it is possible to come up with a comprehensive model that accurately describes our universe, it implies that we will one day be able to come up with a Theory of Everything.

In a paper published in the journal Science Advances, scientists reported that they measured tiny variations in the fine structure constant when measuring light from a quasar 13 billion light years away. 

At the heart of these theories are certain cosmological constants – or, at least they were thought to be constant. But this new study has questioned whether these forces may in fact change at different points of time and space.

In a paper published in the journal Science Advances, scientists reported that they measured tiny variations in the fine structure constant when measuring light from a quasar 13 billion light years away. 

UNSW Science’s Professor John Webb said: “The fine structure constant is the quantity that physicists use as a measure of the strength of the electromagnetic force. It’s a dimensionless number and it involves the speed of light, something called Planck’s constant and the electron charge, and it’s a ratio of those things. And it’s the number that physicists use to measure the strength of the electromagnetic force.” 

Electromagnetism, as a fundamental force, was believed to be constant. However, Prof Webb noticed anomalies in the fine structure constant whereby electromagnetic force measures slightly different in one particular direction of the universe. He said: “We found a hint that that number of the fine structure constant was different in certain regions of the universe. Not just as a function of time, but actually also in direction in the universe, which is really quite odd if it’s correct… but that’s what we found.”

Rather than an arbitrary universal spread, it now appears that it has the equivalent of a north and a south.

The team used the world’s most powerful telescopes to study the light from distant quasars. These are around 12 to 13 billion light years away from us, and their light lets us see the properties of the very early universe. The team made four measurements along the one line of sight to this quasar – when compared with other measurements between us and distinct quasars made by other scientists, the differences became evident. “And it seems to be supporting this idea that there could be a directionality in the universe, which is very weird indeed,” Prof Webb said.

He explained: “So the universe may not be isotropic in its laws of physics – one that is the same, statistically, in all directions. But in fact, there could be some direction or preferred direction in the universe where the laws of physics change, but not in the perpendicular direction. In other words, the universe, in some sense, has a dipole structure to it.” Rather than an arbitrary universal spread, it now appears that it has the equivalent of a north and a south.

This idea is in its very early stages, but the potential to shake up our understanding of science is huge. Our standard model of cosmology is based on an isotropic universe. This is built upon Einstein’s theory of gravity, which explicitly assumes constancy of the laws of nature. But if these laws are found to only be good approximations, it could open the door for some new exciting science and the possibility of revising our understanding of the universe.