Gravitational waves are like super-subtle ripples of gravitational energy moving through (the fabric of) space 鈥� a little like waves after you drop a pebble in the water. Except the pebble would be a or and those waves could pass milliseconds to decades apart, or even longer. Detecting and understanding would advance our understanding of how galaxies have evolved and, even broader, provide a means of studying the universe essentially after the .
The waves of general relativity, but scientists at the Laser Interferometer Gravitational Wave Observatory (LIGO) facilities . The waves came from the merging of two black holes and .
Now, an including researchers at and the , have detected compelling evidence of much more faint gravitational wave signals with of years to decades. They believe the signals come from merging black holes 鈥� called 鈥溾�� 鈥� billions of times more massive than our sun.
At this point, could realistically detect waves this slow. So the researchers harnessed 68 quickly-spinning (dead stars that emit highly regular pulses of energy) scattered around the Milky Way 鈥� essentially creating a gravitational wave detector spanning a huge section of space light years across.
Gravitational waves stretch and compress space as they pass. By timing the subtle differences in the time it takes for the pulses of radiation from these pulsars to reach Earth, the scientists were able to see what appear to be gravitational waves.
鈥淭he large number of pulsars used in the 鈥� analysis has enabled us to see what we think are the first signs of the correlation pattern predicted by general relativity,鈥� says Xavier Siemens of Oregon State University in a statement. Siemens is co-director of the , the group that made the discovery.
Research groups in other parts of the world using similar techniques also announced evidence of gravitational waves this week. The groups are planning to combine their data in the coming months to add certainty to their findings.
Read the findings in a series of papers published in The Astrophysical Journal Letters , , (lead author OSU鈥檚 Jeffrey Hazboun) and . The researchers will also hold a about their discovery on Thursday at 10 a.m.
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