Best Science of 2016: Gravitational Waves Send Shockwave (of Excitement) Around the World

Gravitational waves were detected on September 14, 2015 for the first time by twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA. The signal they picked up was caused by the merger of two black holes 1.3 billion years ago, represented in this artists depiction. (The SXS (Simulating eXtreme Spacetimes) Project)

One of the most remarkable science stories of the year was the discovery, a century after it was predicted by Albert Einstein, that gravitational waves are real. Today Science magazine named the discovery the 2016 Breakthrough of the Year.

Gravitational waves are distortions in the fabric of spacetime. Back in 1915, Einstein hypothesized these ripples would travel throughout the universe, bending and squeezing space like the surface of a trampoline.


It is mass, according to Einstein’s theory of general relativity, that warps the fabric of space. If the mass is great enough, then other objects will fall towards them, as the Earth is pulled toward the Sun in its rotation. We know this as gravitational attraction. When the distortions travel through space, they’re known as gravitational waves.

Earlier this year, researchers with the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) announced that they had discovered direct evidence of gravitational waves, by matching distortions picked up at two highly precise, identical detectors on different sides of the country. They’d each seen the same disturbance at the same time on September 14, 2015. (The feat was repeated on December 26, 2015 when both detectors felt a gravitational wave again.)

A sky map of the southern hemisphere showing the approximate locations of the two gravitational-wave ripples detected by LIGO.
A sky map of the southern hemisphere showing the approximate locations of the two gravitational-wave ripples detected by LIGO. (LIGO/Axel Mellinger)

“There it was!” LIGO team member Daniel Holz told Nature. “And it was so strong, and so beautiful, in both detectors.” Although the shape of the signal looked familiar from the theory, Holz says, “it’s completely different when you see something in the data. It’s this transcendent moment.”

Members of the LIGO collaboration can be found all around the globe including at CalTech, Stanford and Sonoma State University.

Team LIGO has spent much of 2016 upgrading its observatories. As of late November, LIGO is now listening again, straining to hear new ripples. Far from being the end of an era, LIGO is giving rise to a new field of cosmological physics. You can be a part of it by joining “Gravity Spy,” a newly launched citizen science program, that helps researchers separate glitches from true signals. 

 

Best Science of 2016: Gravitational Waves Send Shockwave (of Excitement) Around the World 30 December,2016Danielle Venton

  • Xinhang Shen

    Actually, LIGO’s work does not have much value if it is to prove Einstein’s general relativity because the relativity theory has already been disproved both theoretically and experimentally (see “Challenge to the special theory of relativity” March 1, 2016 Physics Essays). The most obvious evidence disproving special relativity is the existence of the absolute time shown by the universally synchronized clocks on the GPS satellites which move at high velocities relative to each other while special relativity claims that time is relative (i.e. the time on each reference frame is different) and can never be synchronized on clocks moving with relative velocities. We should abandon the wrong relativity theory as well as all other relativistic spacetime based physics theories to open our mind in the search of new theories.

Author

Danielle Venton

Danielle Venton is a host and reporter for KQED.

Before joining KQED in 2015, Danielle was a staff reporter at KRCB in Sonoma County and a writer at WIRED in San Francisco. She is a 2011 graduate of the University of California at Santa Cruz’s science communications program, and has held internships at High Country News and the Monterey County Herald.

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