Fine-Structure Constant Changes Over Space and Time

Astronomers may have discovered a mystery the Universe has been hiding since the Big Bang. New studies demonstrate that the fine-structure constant (FSC), one of the most important measures in Cosmos, was not, and is not, constant throughout time and space.

The FSC, which is also known as α, is a fundamental coupling constant that characterizes the strength of the electromagnetic interaction, one of the four fundamental forces in the Universe. The other three are gravitation, the weak interaction and the strong interaction.

According to the new discoveries, the intensity of the electromagnetic forces differed widely between the two opposite ends of the Universe billions of years ago. The Big Bang is believed to have spawned the Cosmos some 13.75 billion years ago.

The new investigation was conducted by Australian physicists, who used the European Southern Observatory's (ESO) Very Large Telescope (VLT) in Chile to analyze the light of ancient quasars.

These objects are supermassive black holes at the core of distant galaxies, that are tremendously luminous and highly-active. Their light can travel more than 10 billion light-years without experiencing an amount of redshift that would make unusable by science.

As quasar light travels through space, it passes through all sorts of intergalactic and interstellar mediums, that always leave an imprint on its characteristics. The Australian team used these imprints to assess how the value of α changed over time and space, Daily Galaxy reports.

University of New South Wales physicist John Webb – who discovered back in 1998 that the FSC was a part in 100,000 smaller in the distant past than it is today – conducted the new VLT study. He and his team looked at 153 quasars in the southern sky.

The group was puzzled to learn that α was a part in 100,000 larger in the southern sky about 10 billion years ago than it is today. While replicating the 1998 study, the team learned that the northern skies still had a FSC value lower than today.

According to the physicists, these small variations in the fine-structure constant hold considerable implications for astrophysics. If one of the constants on which our understanding of the Universe is built is not necessarily constant, then maybe other values are not constants either.

Further down the line, it may be that not even light has a constant speed, which would have tremendous implications for space studies.