In fact, whenever a new instrument capable of studying the heavens was invented, astronomers had to rethink their understanding of the universe. Scientists have recently revolutionized astronomy by discovering how to observe gravitational waves using new technologies including lasers and mirrors.
Black holes are masses of massive stars with such strong gravity that they can not escape light. When they collide, they release energy in a form called gravitational waves. Collisions that are completely invisible to the naked eye and do not register on the electromagnetic spectrum can only be detected by observing gravitational waves. While Albert Einstein predicted that the waves existed in 1916, it took nearly a hundred years for the scientists to actually observe.
On September 14, 2015, the whole universe shuddered. Well, in fact, it is more accurate to say that it was the date when mankind became aware of a catastrophic event – the merger of the two huge black holes that occurred some 1.3 billion years ago, or the stealing of the line from the star wars "long ago far remote galaxy. "
Since the gravitational waves that were released during the black hole merger 1.3 billion years ago were discharged by the solar system, the space and time fabric itself was compressed and stretched.
Two L-shaped detectors at LIGO in Louisiana and Washington cooperated at the first observation of the gravitational wave. As the wave passed, each L-shaped detector arm, measuring 2.5 kilometers long, lengthened and shortened by a distance of about one thousandth of the diameter of the proton. To get a sense of scale, it's the equivalent of measuring distance from us to another star system Alpha Centauri with the accuracy of human hair width.
Now with the help of another device in Italy, called Virgo, scientists are studying the general features of these black hole collisions and where they take place. Gravitational waves travel at the speed of light, and so, as they pass through Earth, there is a small delay between each detector that records their passage. This delay is used to determine where the collision occurred. This technique is similar to the way geologists use earthquake arrival times on different seismographs to determine the origin of the earthquake.
With LIGO and Virgo detectors, scientists can better understand what happens when very tough astronomical organs collide. The collision of neutron stars, which are shells of stars slightly smaller than black holes, may also reflect the gravitational waves found on Earth. And, of course, a black hole with a neutron star could join.
In a recently published document, gravity waves astronomers have described in detail 11 of these collisions – four of which have never been reported before – since detectors began operating in 2015. Due to the downtime of the device, one detection every 15 days. In the most impressive example, the two massive black holes merged to form about 80 times the weight of the sun, making it the heaviest star black hole ever seen.
For a fraction of a second of collision, it released more energy than everything from the light released from every star in the entire visible universe. It was a huge thing. And everything happened in a 9 billion light-years galaxy.
Before LIGO's first observation, scientists did not think that stars could form black holes weighing more than about 15 or 20 times heavier than the sun. So with just 11 observations, scientists were forced to rethink their theories.
While the announcement of excessive black holes leads to a good headline, this recent paper has less breathtaking, but scientifically more significant impact. Observation of one thing can be curiosity. But few occurrences later scientists may begin to draw some conclusions.
By combining the known performance capabilities of the detector with the observed locations and the speed at which they are detected, astronomers can begin to tell how often they occur. While scientists are working with a small sample size, they now estimate that in the space of somewhere between half a billion and a billion light-years, we can expect to see one merger of a black hole per year.
And the story is not finished. Detectors are currently offline, subject to updates that allow them to guard two times away from Earth. This will allow them to examine the volume eight times larger than before. The days of gravimetric wave astronomy are only in diapers and there is no doubt a huge surprise.