Across the Universe: does physics have local by-laws?

NASA image
Monday, 31 October, 2011
Bob Beale

One of the laws of nature may change with location in the Universe, a study published today in the journal Physical Review Letters suggests.

A cherished principle in science - the constancy of physics - may not be true, according to the research carried out at the University of New South Wales, Swinburne University of Technology and the University of Cambridge.

The study found that one of the four fundamental forces, electromagnetism - measured by the so-called fine-structure constant and denoted by the symbol alpha - seems to vary across the Universe.

The first hints that alpha might not be constant came a decade ago when Professor John Webb and Professor Victor Flambaum, in the School of Physics and other colleagues at UNSW and elsewhere, analysed data from the Keck Observatory, in Hawaii. Those observations were restricted to one direction in the sky. 

However, now Webb and colleagues (Dr Julian King, PhD student Matthew Bainbridge and Professor Victor Flambaum at UNSW; Dr Michael Murphy at Swinburne University of Technology; and Professor Bob Carswell from Cambridge University) have doubled the number of observations and measured the value of alpha in about 300 distant galaxies, all at huge distances from Earth, and over a much wider area of the sky. The new observations were obtained using the European Southern Observatory’s Very Large Telescope in Chile.

“The results astonished us,” says Professor Webb. “In one direction - from our location in the Universe - alpha gets gradually weaker, yet in the opposite direction it gets gradually stronger.”

Dr King says the discovery, if confirmed, has profound implications for our understanding of space and time and violates one of the fundamental principles underlying Einstein's General Relativity theory.

Professor Flambaum says that such violations are actually expected in some more modern ‘Theories of Everything’ that try to unify all the known fundamental forces: “The smooth continuous change in alpha may also imply a much larger universe than our observable patch - possibly infinite.”

According to Dr Murphy: "Another currently popular idea is that many universes exist, each having its own set of physical laws. Even a slight change in the laws of Nature means they weren’t ‘set in stone’ when our Universe was born. The laws of Nature you see may depend on your ‘space-time address’ – when and where you happen to live in the Universe.”

Professor Webb says these new findings also offer a very natural explanation for a question that puzzled scientists for decades: why do the laws of physics seem to be so finely-tuned for the existence of life? “The answer may be that other regions of the Universe are not quite so favourable for life as we know it, and that the laws of physics we measure in our part of the Universe are merely "local by-laws",  in which case it is no particular surprise to find life here,” he says.

This suggests, says Flambaum, that life appeared in the region of the Universe where the fundamental constants are suitable.

Media contacts:

John Webb –  m. +61 (0)414 011 176

Julian King – mobile +61 (0)411 125 025

Michael Murphy – mobile +61 (0)405 214 461

Victor Flambaum – +61 (0)2 9385 4571

UNSW Faculty of Science media: Bob Beale +61 (0)411 705 435

Swinburne University media: Lea Kivivali +61 (0)410 569 311