Scientists strain to 'hear' gravitational waves

Researchers have brought the world one step closer to 'hearing' gravitational waves - ripples in space and time predicted by Albert Einstein in the early 20th century. The research, conducted at NASA's Jet Propulsion Lab (JPL) in California, tested a system of lasers that would fly aboard the proposed space mission called Laser Interferometer Space Antenna, or LISA.  The mission's goal is to detect the subtle, whisper-like signals of gravitational waves, which have yet to be directly observed. This is no easy task and many challenges lie ahead, reports the journal Physical Review Letters. Just as a boat sailing through the ocean produces waves in the water, moving masses like stars or black holes produce gravitational waves in the fabric of space-time.  A more massive moving object will produce more powerful waves, and objects that move very quickly will produce more waves over a certain time period. The new JPL tests hit one significant milestone - demonstrating for the first time that noise or random fluctuations in LISA's laser beams can be hushed enough to hear the sweet sounds of the elusive waves, according to a NASA statement. "In order to detect gravitational waves, we have to make extremely precise measurements," said Bill Klipstein, study co-author and physicist at JPL.  "Our lasers are much noisier than what we want to measure, so we have to remove that noise carefully to get a clear signal. It's a little like listening for a feather to drop in the middle of a heavy rainstorm."  The JPL team is one of many groups working on LISA, a joint European Space Agency and NASA mission proposal, which would launch in 2020 or later, if selected.