A new investigation method is now available

Jul 22, 2010 06:50 GMT  ·  By

Astrophysicists can now use a new scientific method to determine whether things such as dark energy actually exist. This concept, for example, was introduced decades ago, in order to explain why galaxies were found to be pushing away from each other. It is currently widely accepted that dark energy makes up for about 74 percent of everything in the Universe. But efforts of detecting it have thus far failed, which has left investigators wondering if the entire theory is not corrupt. With the aid of a new radio telescope technique, they could soon get the answer they are looking for, Space reports.

What this allows astronomers to do is peer very far back into the Universe, all the way to a time when the Cosmos was just a small fraction of its current age. This ability will allow experts to conduct extremely accurate studies of how everything evolved, which could in the end tell them whether things such as dark energy and dark matter really exist. The truth is that, if the theories are proven false, there would be nothing to replace them with. Dark energy is believed to be responsible for the accelerated expansion of the Universe, and physicists say that classical models cannot account for this phenomenon.

Measuring large-scale cosmic structures is one of the ways that astronomers believe they can take in figuring out these essential cosmic riddles. Using a process called intensity mapping, scientists can now measure the radio emissions produced by the earliest hydrogen clouds. It could be that this radiation left detectable traces in its wake, such as for example influencing the way galaxies are distributed throughout the Cosmos. The accuracy of the dark energy theory can be either confirmed or infirmed by intensity mapping studies, depending on what findings are made, experts say.

“Our project mapped hydrogen gas to greater cosmic distances than ever before, and shows that the techniques we developed can be used to map huge volumes of the Universe in three dimensions and to test the competing theories of dark energy,” expert Tzu-Ching Chang explains. He holds a joint appointment at the Academia Sinica, in Taiwan, and the University of Toronto, in Canada. The team he led used the Robert C. Byrd Green Bank Telescope (GBT), in Virginia, for the investigation. The instrument is operated by the US National Science Foundation (NSF).

“Since the early part of the 20th century, astronomers have traced the expansion of the Universe by observing galaxies. Our new technique allows us to skip the galaxy-detection step and gather radio emissions from a thousand galaxies at a time, as well as all the dimly-glowing material between them,” adds Carnegie Mellon University researcher and team member Jeffrey Peterson. Details of how intensity mapping can be used for solving cosmic mysteries appear in the July 22 issue of the esteemed scientific journal Nature.