Also available at my science blog www.scientificbird.wix.com/scientificbird
Specific article: http://scientificbird.wix.com/scientificbird#!Breaking-News-Gravitational-Waves-Have-Been-Proven/c1sp5/56bcc9dd0cf2fd311cdf926f
Gravitational waves have just been discovered at the Laser Interferometer Gravitational-Wave Observatory (LIGO). LIGO detected gravitational waves on September 14th, 2015, but in a press conference in Washington State today on February 11th, 2016, David Reitze, executive director at LIGO, announced the discovery. “Ladies and gentlemen, we have detected gravitational waves. We did it,” he announced to the cheers of scientists.
Gravitational waves are part of Einstein’s theory of general relativity. The gravitational waves announced today were detected from the merging of two black holes that happened 1.3 billion years ago, whose gravitational waves are just now reaching Earth. And because gravitational waves have just been proven, another aspect of Einstein’s theory of general relativity has been proven, like many other aspects of his theory.
The gravitational waves were discovered by LIGO using lasers and mirrors. A laser is split and reflected off of mirrors. Normally, the beams cancel each other out, meaning LIGO has not detected any gravitational waves. But when a wave passes, the mirrors move, the beams have different frequencies, and LIGO detects a gravitational wave. When the light frequencies are converted into a sound wave, it is a chirp rising “to the note of middle C before abruptly stopping,” as Dennis Overbye of the New York TImes describes it.
Gravitational waves, which travel at the speed of light, will allow scientists to observe the movements of massive objects by observing gravitational waves instead of observing other forms of energy emitted by the objects. Scientists will be able to measure mass by gravitational waves; the more massive an object is, the stronger the gravitational waves are. Scientists will also be able to observe distance. And gravitational waves may be discovered to have more implications than previously thought.
Bibliography
Castelvecchi, Davide. Nature.com. Nature Publishing Group, 9 Feb. 2016. Web. 11 Feb. 2016. <http://www.nature.com/news/gravitational-waves-6-cosmic-questions-they-can-tackle-1.19337?WT.mc_id=SFB_NNEWS_1508_RHBox>.
Grush, Lauren. "Scientists Have Finally Proven Einstein's Century-old Theory about Gravitational Waves." The Verge. 11 Feb. 2016. Web. 11 Feb. 2016. <http://www.theverge.com/2016/2/11/10965312/einstein-gravitational-waves-discovered-announced-video>.
Overbye, Dennis. "Scientists Detect Gravitational Waves, Proving Einstein Right." The New York Times. The New York Times, 11 Feb. 2016. Web. 11 Feb. 2016. <http://www.nytimes.com/2016/02/12/science/ligo-gravitational-waves-black-holes-einstein.html?_r=0>.
Radford, Tim. "Gravitational Waves: Breakthrough Discovery after Two Centuries of Speculation." The Guardian. Guardian News and Media, 11 Feb. 2016. Web. 11 Feb. 2016. <https://www.theguardian.com/science/2016/feb/11/gravitational-waves-discovery-hailed-as-breakthrough-of-the-century>.
