DEC 19, 2014

Catching A Wave From Space

WRITTEN BY: Brenda Kelley Kim
Ever since Albert Einstein revolutionized science with his Theory of Relativity, scientists have believed that major events in the galaxy, such as supernova explosions or black hole mergers, must leave some kind of trace. Most researchers believe that this trace creates gravitational waves. These are like ripples in the space-time continuum that roll outwards into the universe from the event that precipitated them.

In order to detect these waves however, researchers had to create and build an entire system to identify any signs of the theoretical waves. From 2002 to 2010 hundreds of scientists collaborated and created the Laser Interferometer Gravitational-wave Observatory (LIGO). It consisted of two observatories 1865 miles apart working in unison. The observatories, one in Livingston, Louisiana and the other in Richland, Washington are managed by CalTech and MIT and funded by the National Science Foundation (NSF)

Despite all the efforts directed at the project, no waves have ever been detected. Most astronomers believe they exist however, and could be discovered given the right tools. That's why a follow up to LIGO has been created. International organizations such as the UK Science and Technologies Facilities Council, the German Max Planck Society and the Australian Research Council have joined with the NSF to support the creation of ALIGO, or Advanced Laser Interferometer Gravitational-wave Observatory. ALIGO is expected to be up and running in 2015.

Besides the astronomical problems a system like ALIGO presents, there is the consideration of the "Big Data" issue. The observatories take in huge volumes of data that then must be analyzed to determine their meaning. In the case of a positive identification of a gravitational wave candidate, this process must happen quickly, so the location of the waves can be identified and used for further study.

During the planning stages of ALIGO, the researchers realized they needed much more data and computer processing power. Fortunately, another NSF project, the Extreme Science and Engineering Discovery Environment (XSEDE) had the resources necessary. They took the computing environment of LIGO and combined it with the Stampede supercomputer at the Texas Advanced Computing Center. Along with support from the High Throughput Condor Group at the University of Wisconsin, the ALIGO team now had priority access to a massive supercomputer to crunch the large amounts of incoming data.

While they originally used code from the LIGO project, the addition of the larger capacity computers allowed the team to make the ALIGO software even more efficient, resulting in cost savings. While the idea of space and astronomy research brings to mind rocket ships, astronauts and space travel, the researchers on the ALIGO project have shown that what happens on the ground is vital as well. Thanks to high performance computing, the team was able to take the large amounts of data gathered from the observation of electromagnetic radiation and neutrinos in space-a process known as multi messenger astronomy-and use it to possibly "catch a wave" rolling outward from the universe and along the curvature of space and time.