The 14 September 2015 spacetime shuddered two black holes merged into a galaxy located about 1,300 million light years from Earth. This time the cosmic tremor triggered by the violent event was not lost on Earth.
In the United States recently completed two detectors of gravitational waves stirred, even before he began his official observation period. With this, the Observatory Laser Interferometry Gravitational Wave (Ligo) got the first direct demonstration of the existence of after Albert Einstein’s predicted gravitational waves, one hundred years.
“This detection is the beginning of a new era, the era of astronomy of gravitational waves is already a reality,” the Argentina Dr. Gabriela Gonzalez, spokeswoman said yesterday from Washington Ligo team and professor of astrophysics at Louisiana state university.
“It is the beginning of what many describe as astronomy of gravitational waves,” says one of the founders of Ligo, Professor Rainer Weiss of the Massachusetts Institute of Technology.
The executive director of the laboratory Ligo, David Reitze, said that “we have taken months to see that they were really gravitational waves. But what is really exciting is what comes after, we opened a new window on the Universe, “he added,
the gravitational waves will allow to observe massive objects such as supernova explosions or merging black holes. According to Einstein, these waves are generated when the masses are accelerated, propagating at the speed of light and compress and stretch spacetime.
Using ultra-sensitive laser Ligo hear the vibrations of the universe. The lasers are arranged inside two arms of four kilometers long each, arranged in L.
If a gravitational wave passes by the observatory, the length of both arms changes minimally. “The merger of black holes compressed and stretched his arms up to two attómetros, about 1,000 times less than the diameter of the nucleus of an atom of hydrogen,” explains Professor Bruce Allen, director at the Max Planck Institute for Gravitational Physics Potsdam and Hannover, which is involved in research and where I first noticed the sign. This clearly appeared before investigators monitors four days before Ligo officially comenzase with observation, had just finished when the technical preparations. “It was the first day the detectors functioned a uniformly stable,” said Professor Karsten Danzmann, also director at the Max Planck Institute.
Despite the spectacular nature of this first direct evidence, and almost no researchers doubted the existence of gravitational waves. But scientists excited watching them the possibilities that opens with this finding. “We have not only proved the existence of gravitational waves, but a dual system of two black holes. Two discoveries at once!” Celebrates Allen.
“The double black holes can only be demonstrated from gravitational waves as they do not emit light or electromagnetic radiation,” adds Professor Alessandra Buonanno, director for Gravitational Physics in Max Planck.
The researchers analyzed in detail the fusion of September 14. “Black holes were 29 and 36 times the mass of our Sun, respectively. However, the merged black hole only has 62 solar masses,” says Allen.
According to the mass-energy equivalence established by Einstein in his theory of relativity, the other three bodies were irradiated as energy of gravitational waves in less than a quarter of a second. “For a short time, this object was the energy of the whole universe! And yet remained completely dark,” says Danzmann.
“Nothing diverts gravitational waves. With them we can observe in detail the objects of the deepest cosmos,” says Weiss. “One of the most exciting observations would be that of a supernova. Using gravitational waves we could see what is really happening in the heart of a stellar explosion that guy.”
What is a gravitational wave? It is a tiny ripple of spacetime that propagates in the universe at the speed of light.
These waves were presented conceptually 100 years ago by Albert Einstein, the famous physicist, as a consequence of his theory general relativity in 1915.
Einstein described gravity as a warping of space. The masses, like the sun for example, curved space. A bit like when someone gets on a trampoline.
If the masses are small, the deformation is weak (a grape on a trampoline not altered). If the masses are large, the deformation is important (a person on a bed, deforms the elastic fabric).
If the masses are moving and acceleration, these deformations are displaced and spread through space, forming gravitational waves.
to illustrate these oscillations is often used the image of waves propagating on the surface of a lake when a stone is thrown. The further away, the wave becomes weaker.
The gravitational waves that are looking for are produced by violent astrophysical phenomena such as the merger of two black holes or the explosion of massive stars.
The others are too sensitive so that we can observe. But around us without our being aware of it without consequences for us.
directly detect these gravitational waves is one of the predictions of Einstein confirmed. It is a milestone for the physical.
In addition to the various electromagnetic means for observing the cosmos now, astrophysicists have a new tool for observing the violent phenomena in the Universe. The detection of these gravitational waves would see what happens “inside” during the merger of two black holes, for example.
The technological advances made to hone wave detectors could be reflected in our daily life.
How is organized the detection of gravitational waves? Albert Einstein was aware that it would be very difficult to observe gravitational waves. For about 50 years nothing happened particular. But then, in 1950, the American physicist Joseph Weber took aim find and built the first detectors.
Meanwhile, it became evident indirect evidence of the existence of gravitational waves.
in 1974, the observation of a pulsar-a neutron star that emits an intense electromagnetic radiation in a given, as a Faro-, orbiting another star address, allowed to conclude that these waves exist.
Russell Hulse and Joseph Taylor received the Nobel Prize in Physics in 1993 for his discovery of the pulsar.
in the 1990s, the United States decided to build the Ligo, an observatory consisting of two giant instruments which used as an infrared laser light source. One of them is in Louisiana and the other in the state of Washington.
France and Italy did the same with Virgo, near the city of Pisa.
In 2007, Ligo and
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