GLOBAL: Earth's laws still apply in distant universe

The laws of nature are the same in a distant universe as they are here on Earth, according to new research conducted by an international team of astronomers. Results of the research, published in Science last Friday, found that one of the most important numbers in physics theory, the proton-electron mass ratio of 1,836.15, is almost exactly the same in a galaxy six billion light years away as it is in laboratories on Earth.

Researchers from the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan, the Max Planck Institute for Radio Astronomy in Germany, Swinburne University of Technology in Melbourne and the University of New South Wales in Sydney were involved in the project.

Swinburne astrophysicist and lead author of the study, Dr Michael Murphy, said the finding was important as many scientists wondered whether the laws of nature could change at different times and in different places in the universe.

"We have been able to show that the laws of physics are the same in this galaxy half way across the visible universe as they are here on Earth," Murphy said.

The astronomers determined this by effectively looking back in time at a distant quasar. The quasar's light, which took 7.5 billion years to reach Earth, was partially absorbed by ammonia gas in an intervening galaxy.

"Not only is ammonia useful in most bathroom cleaning products, it is also an ideal molecule to test our understanding of physics in the distant universe," Murphy said. "The wavelengths at which ammonia absorbs radio energy from the quasar are sensitive to this special nuclear physics number, the proton-electron mass ratio.

"By comparing the ammonia absorption with that of other molecules, we were able to determine the value of the proton-electron mass ratio in this galaxy, and confirm that it is the same as it is on Earth."

He said the astronomers' aim was to continue testing the laws of nature in as many different places and times in the universe as possible: "We want to see how well the laws of nature stand up in untested situations by looking well beyond our little portion of space and time."

To do this, the astronomers need to locate more absorbing galaxies because the one studied was the only one of its kind known in the universe. But scientists believe there must be many more although they do not have the technology to find them. That problem could be overcome though the use of a proposed Square Kilometre Array (SKA) telescope project.

"The SKA is the largest, most ambitious international telescope project ever conceived.
When completed it will have an enormous collecting area, and will allow us to search for more absorbing galaxies," Murphy said.

The location of the SKA, which has been short-listed to Western Australia and South Africa, will be announced within the next two years.

By continuing their research into the forces of nature, the astronomers also hope to find a window into the extra dimensions of space that many theoretical physicists think may exist.