Have you heard the story about the star who died twice? In 2014, astronomers witnessed the explosion of the Refsdal supernova. Then, 360 days later, another explosion occurred.
This strange series of events was due to a phenomenon called gravitational lensing. In this phenomenon, a massive object distorts the fabric of the universe to the extent that it bends light. The paths of the flashes from the supernova changed in this way on their way to us, so some of them took different routes and arrived at different times. In this extreme example, it was almost a year apart.
As this story shows, gravitational lenses have been around for a while, but they’re now entering a fascinating new chapter. Scientists know that it’s not just light that can be lensed, but gravitational waves as well. It is a disturbing concept in which the ripples in space and time are themselves distorted by the curvature of space. It’s also a hugely important phenomenon that could illuminate the secret interior of neutron stars, solve mysteries about the power of dark energy, and test gravity itself more acutely than ever before. And here’s the best part. We may be on the verge of discovering lensed gravitational waves for the first time.
No one is under any illusion that this is terribly difficult. Still, I have a hunch that it will happen sooner or later. And there are tricks we can use to speed up discovery. “It’s exciting and it’s coming,” said Simon Biller of Stony Brook University in New York. “There…
Source: www.newscientist.com
