An international team of researchers has detected gravitational waves from a black hole for the second time in science history. The unique event occurred on December 26 when detectors in Washington and Louisiana were able to catch signals, coming from 1.4 billion light years away.
New findings reconfirm the theory of general relativity, presented in 1915 by the German scientist Albert Einstein. The task was achieved by the Laser Interferometer Gravitational-Wave Observatory (LIGO), which is operated by Caltech and the Massachusetts Institute of Technology.
The signals were emitted by two black holes in their final orbits, which then fused into a single body. Minutes after gravitational waves announced their presence, LIGO detectors in Hanford Washington and Livingston Louisiana confirmed they were coming from the distant universe.
New signals were coincidentally emitted from almost the same distance as the first signals, detected on September 14, last year. Researchers have called the phenomenon as “the Boxing Day event,” given that messages were caught near the end of the first observation phase.
Two different events, some similarities
The two detectors identified the newly detected gravitational wave almost at the same moment. Scientists proposed that the source might be located “somewhere in a ring of sky about midway between the detectors.”
The two black holes that emitted signals during the Boxing Day event were 14 and eight times the mass of our sun, respectively. The first couple of black holes detected on September 14 were 35 and 29 times the mass of our sun, respectively.
Researchers are now expecting to calculate the rate of black hole fusions in the universe. This time, the investigation would be based on real observation instead of theory. The LIGO team added that detectors have been “sensitive enough” to detect gravitational waves every two months.
“Of course with just a few signals, our estimate has big uncertainties, but our best right now is somewhere between 9 and 240 binary black hole coalescences per cubic Gigaparsec per year, or about one every 10 years in a volume a trillion times the volume of the Milky Way galaxy!,” said researchers.
Here is a video by the Massachusetts Institute of Technology about the new LIGO’s discovery:
A new observation phase begins in the Fall of 2016
The next observation phase starts in autumn this year. LIGO will now increase the sensitivity of the detectors, seeking to catch a black hole fusions. The team also hopes to detect gravitational waves from “neutron-star binary mergers.”
LIGO is also planning to add a new detector called Virgo, which would provide helpful information about sources in the sky. The collision of two black holes had never been observed before, although scientists such as Albert Einstein and Professor Stephen Hawking said it could occur.
Salvatore Vitale, a member of the LIGO team, told MIT News that researchers are planning to conduct further investigations, and make “interesting science” about black holes. New findings from LIGO were published on Thursday in the journal Physical Review Letters.
— LIGO (@LIGO) February 11, 2016
The universe is being studied in ways that were never imagined before
The National Science Foundation has invested an estimated $1.1 billion, for more than 40 years, to build LIGO laboratories capable of detecting gravitational waves. For decades, scientists had been trying to prove that Einstein was right.
The theoretical physicist changed the way the universe was perceived in 1915. He said that matter and energy distort the geometry of the universe. The result of this distortion would be ripples of gravity or gravitational waves.
If researchers at LIGO continue to catch information about black holes, they would be able to understand better how do they merge. Two main theories could explain such as phenomenon.
The first theory proposed that black holes come from exploding stars that circle each other until they turn into black holes that continue moving around and merge themselves.
A second theory said that two independent black holes “might become gravitationally bound,” fusing themselves as a consequence, according to MIT News.
Amazing discovery of gravitational waves! Thanks Einstein pic.twitter.com/lcolBF1zzJ
— Man timeless (@newsphysicsita) June 16, 2016
According to scientist Salvatore Vitale, the team is interested in determining which scenario occurs with more frequency. However, they need to collect data from more gravitational waves. LIGO will jointly work with Virgo, a 9,800-foot-long detector located near Pisa in Italy.
Many scientists report that their lives have changed since the first detection of gravitational waves since it could be the only phenomenon capable of explaining “the very beginning of time.” Researchers at LIGO have estimated that black holes merge in the universe every one hour.
“The first event was so beautiful that we almost couldn’t believe it. The fact of having seen another gravitational wave proves that indeed we are observing a population of binary black holes in the universe,” added Vitale, who is also a research scientist at the MIT.
— Nature News&Comment (@NatureNews) June 15, 2016