In Brief

How Cosmic Clocks Help Search for Gravitational Waves (Video)

In a new video from Physics World, scientists from the Jodrell Bank Observatory near Manchester in the United Kingdom discuss how natural time keepers called pulsars — which are actually the condensed left-over material from burned-out stars — could help the search for gravitational waves. Einstein predicted that very massive, energetic events (like two stars merging together) could create ripples in the fabric of space, the way a stone creates ripples on the surface of a pond. The ripples aren't made of light or matter, but of space itself. These are called gravitational waves.

So far, astronomers have not been able to detect gravitational waves directly, and some astronomers are choosing to take an indirect path. Pulsars earned their name because their light appears to pulse on and off. In some cases, the pulsar's blinking is so regular, it exceeds the precision of any clock that can be built by humans. An interruption in that regularity, therefore, must come from an external event. Check out the video to see how interruptions to these regular pulses of light could indicate the presence of gravitational waves. 

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Calla Cofield
Senior Writer

Calla Cofield joined's crew in October 2014. She enjoys writing about black holes, exploding stars, ripples in space-time, science in comic books, and all the mysteries of the cosmos. Prior to joining Calla worked as a freelance writer, with her work appearing in APS News, Symmetry magazine, Scientific American, Nature News, Physics World, and others. From 2010 to 2014 she was a producer for The Physics Central Podcast. Previously, Calla worked at the American Museum of Natural History in New York City (hands down the best office building ever) and SLAC National Accelerator Laboratory in California. Calla studied physics at the University of Massachusetts, Amherst and is originally from Sandy, Utah. In 2018, Calla left to join NASA's Jet Propulsion Laboratory media team where she oversees astronomy, physics, exoplanets and the Cold Atom Lab mission. She has been underground at three of the largest particle accelerators in the world and would really like to know what the heck dark matter is. Contact Calla via: E-Mail – Twitter