Gravitational waves: 7 questions about the event, Nobel scale – TASS

The merger of two “black holes”, in which there was a very large emission of gravitational waves

© Caltech / MIT / LIGO Laboratory

Scientists the United States confirmed the existence of gravitational waves, predicted almost one hundred years ago, the general theory of relativity, Albert Einstein. Why is this discovery so important and how it was done – in the material TASS

What are gravitational waves

• Gravitational waves – this fluctuation fabric of space -Time to flee from massive objects moving with variable acceleration. Due to the relative weakness of the gravitational force (compared to others) waves have a very small amount, it is difficult to register. Similarly, moving electrical charge creates electromagnetic waves, but they are much easier to register.

What does Albert Einstein?

• The gravitational waves predicted by Albert Einstein in the framework of the theory of relativity a hundred years ago, but experimental attempts to find them ended in failure. Even strong gravitational waves cause small changes: objects distant from each other at a distance meter will fluctuate as if the space-time wave and get something closer, then farther apart on 10- ¹⁸ – 10 -. ²³ m
• This is why scientists are expected to detect gravitational waves just by very heavy objects such as colliding galaxies, rotating black holes or binary star systems

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How the discovery was made?

• Search for gravitational waves actively was conducted with approximately 60-ies of the last century. An important theoretical contribution to this work made by Soviet scientists and Michael Gertsenshtein Vladislav Pustovoyt who proposed in 1962 to use for this purpose a modified Michelson interferometer Alberta. This method, however, is extremely complex and expensive, so a long time, scientists have been trying to use more cost-effective tools
• In collaboration LIGO (Laser Interferometer Gravitational Wave Observatory) used to do this terrestrial gravitational telescopes -. Enormous L-shaped antenna with shoulder length of four kilometers. Inside them under high vacuum spread laser beams are reflected by suspended at opposite ends of the antenna dish. And because the gravitational wave periodically expand and contract the shoulders of the telescope, different rays, marching in different optical paths, we come to the exit with a few delays. That they ultimately were recorded by experimenters occurring in the interaction of rays characteristic interference pattern
• From these data, scientists have concluded that the rejection at the level of 10-19 m. – Signal, indicating that the passage of gravitational waves generated by the system two black holes at a distance of about 50 million light-years from Earth.

When the discovery was made?

• Gravitational waves were recorded September 14, 2015 at 13.51 Moscow time at the same time two specialized observatories – in Louisiana and Washington, as an official member of the project LIGO announced the discovery of gravitational waves February 11, 2016 at a press conference, both held in Washington, Moscow and other cities <. /> li>

What is the LIGO?

• Mezhdurnarodny project LIGO (laser interferometer gravitational-wave Observatory), the laser interferometer gravitational wave observatory . The project was proposed in 1992 by Kip Thorne, Ronald Drever at Caltech and Rainer Weiss of the Massachusetts Institute of Technology.
• Russian physicists from the beginning participated in the LIGO project to search for gravitational waves and obtained important results.
• LIGO project started in 1992, in a difficult time for Russia, but Russia was connected to it. One of the pioneers of gravitational-wave research in the world – the Russian physicist Vladimir Braginsky – created on the basis of the Physics Department of Moscow State University school students that were able to actively participate in the project, to obtain important results
• In the experiments, participated actively research group under the leadership of. Professor of the physics Department of Moscow State University Valery Mitrofanov and Corresponding member of the Russian Academy of Sciences Alexander Sergeev (Institute of applied physics RAS, Nizhny Novgorod).

What does the discovery of gravitational waves?

• The opening should be another confirmation of the general theory of relativity, and open the way to a long-standing dream of physicists – the creation of the theory of quantum gravity, and possibly even a grand unified theory that describes all kinds of physical interaction in the same terms and equations
• “We are opening a new era -. the era of gravitational wave astronomy This can be compared with the advent of the telescope and astronomy We have a new tool for the study of the universe.” – says one of the project participants, the head of the group “Coherent microoptics and radiofotonika “Russian quantum Centre (RCC) Mikhail Gorodetsky.
• The experts consider this event,” the opening of the Nobel scale “because it means addressing a hundred puzzles.

How worth opening?

• the total project cost amounted to about $ 620 million.
• For many years, the LIGO isolated money without any assurance that these investments ever pay off . Moreover, the chance that researchers will be able to catch gravitational waves has been negligible, but, nevertheless, year after year, funding extended. And, as it turned out, for good reason: as so often happens in science, thanks to the “useless” investments was quite a discovery that changed our view of the universe

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