Scientists prepare to announce the existence of gravitational waves
The proof of the existence of gravitational waves, predicted by the general theory of relativity (GR) of Albert Einstein, is going to be presented by American scientists next Thursday. These waves, according to the microblogging of Arizona State University cosmologist Lawrence Krauss, were discovered by the upgraded detectors of the LIGO observatory. We asked Pavel IVANOV, a leading researcher in the Department of Theoretical Astrophysics of the Astro-Space Center of the Lebedev Physical Institute, to explain to the readers of MK the significance of gravitational waves.
So where did it all start? If in a global sense, then, of course, with the general theory of relativity of Albert Einstein, which predicted that a cosmic body flying with a changed acceleration creates a perturbation of space-time - a gravitational wave. Indirectly, its existence has already been proven as a result of the convergence of close systems of binary stars - they lost energy to the radiation of gravitational waves. But until recently it was not possible to register the waves themselves because of their small magnitude.
And now there is evidence that the LIGO detector, the most sensitive device to date and specially created for fixing gravitational waves, succeeded. He recorded space distortions after observing the merger of two massive black holes with masses of 29 and 36 solar masses. After the merger, the mass of the object was 62 solar masses.
Photo: ru.wikipedia.org
This information, in fact, did not leak from LIGO. In mid-January, University of Arizona theorist Lawrence Krauss reported the sensation on Twitter. But the scientific community started talking seriously about the discovery of gravitational waves only after the theoretical physicist Clifforth Burjess and the website of the Science journal announced about the upcoming conference on February 11.
So, what are we expecting from the opening? I ask Ivanov
Promotional video:
- Proof of the existence of gravitational waves will open a new window to the universe for humanity. We will receive an additional tool for studying it to all the ranges of electromagnetic waves that we already have: from radio waves to gamma radiation. If we reliably register gravitational waves, we can learn a lot about black holes, neutron stars, how they merge, how they evolve, and so on. Well, about the Universe itself, of course …
After what the search for gravitational waves began?
“We know that many bodies that lose energy emit gravitational waves. A double pulsar was discovered, that is, two neutron stars orbiting relative to each other. When we measured the orbit of the pulsar, we found that it becomes smaller precisely due to the radiation of gravitational waves. Only for this pulsar, for the discovery of the radiation effect, scientists were given the Nobel Prize!
Why is it so difficult to detect a gravitational wave?
- It is very weak: when it passes, it causes a shift in the length of the observing instrument by 10 to -23 times! Scientists needed enormous funds and efforts to learn how to measure such weak signals. And we are not yet saying that they were discovered … There are several experimental installations in the world with the help of which specialists want to catch the displacement. One of them is LIGO, a laser multi-kilometer interferometer.
“So, with the help of gravitational waves, you can better study the dynamics of black holes. What's the difference with electromagnetic waves?
- With the help of electromagnetic radiation, the study is more difficult - there are many uncertainties, one must always take into account the dynamics of the gas …
If the existence of gravitational waves is proven, who is the main contender for the Nobel Prize?
- If the prize is given, then, most likely, not to theorists, but to those who deal with instruments. Although our scientists also made a great contribution to the theory of gravitational waves. In Soviet times, such a person, of course, was Yakov Zeldovich and representatives of his school, now the direction is headed by Corresponding Member of the Russian Academy of Sciences Vladimir Braginsky. From foreign colleagues, he collaborates on this issue with Kip Thorn.
Is Kip Thorne a consultant for the Interstellar movie, which features wormholes - time-space tunnels very popularly?
- I understand your hint. But no, wormholes have a completely different status, both theoretical and observational. These are much more fantastic things than gravitational waves, the existence of which we do not doubt.
But, as we understood from the film, wormholes (or "wormholes") are precisely due to gravitational waves …
“No, these waves can never form a wormhole. Within the framework of the existing theory, they cannot be made at all, they must exist initially, from the very beginning of the expansion of the Universe. And, in order to support them, so that they do not collapse, you need a substance with unusual properties, which has a negative energy density. In general, wormholes are a hypothetical object, theory does not prohibit them, but so far there is no understanding of what they should consist of.
Natalia Vedeneeva