Gravitational waves: “This is the first real evidence of the existence of black holes” – Liberation

Thursday, February 11, scientists Ligo and Virgo project announced the first detection of gravitational waves predicted by Albert Einstein in the theory of general relativity. This discovery opens a new window on astronomy, gravitational astronomy. They also observed this occasion the coalescence of two black holes. Marc Lachièze-Rey, laboratory research director Astroparticle and Cosmology at the University of Paris VII, author of Einstein on the beach: relativity in a deckchair (Wiley, 2015) returns to these discoveries and implications

Read also the collision opens a new window in astronomy. – Libération

How Thursday’s discoveries are they linked with Albert Einstein’s discoveries?

Albert Einstein predicted the existence of gravitational waves, before returning to his prediction then finally confirmed in 1916. for if the theory of relativity is true, the existence of gravitational waves is mandatory. Thursday’s observation is a confirmation of the general theory of relativity with greater precision than before and in a more interesting area.

In fact, until today, we have tested the theory in the solar system or the binary pulsar PSR B1913 + 16. Thanks to the discovery, it is tested in extreme gravitational field, a binary black hole. In addition, the calculations made by this detection confirms the theory with an accuracy better than what we had for the pulsar. Following their comments, Ligo team of researchers tried to test different theories of general relativity that but none have done better Einstein.

among the various discoveries related to this observation, what can you hold?

the real surprise of this discovery is the first real evidence of the existence of black holes. So far, some researchers may have doubts about these stars. Until today, there was circumstantial evidence. But the wave observed lets you know it comes from the meeting of two black holes, thereby proving their existence.

The black holes existed only on paper, even long after death Einstein. They were solutions of general relativity that could be interpreted as such. But it’s not because of mathematical solutions exist that necessarily have a correspondence in the real world. Mathematically, for example, time travel can be conceivable, but actually, it’s much more complicated. About black holes, after this discovery, the consensus will grow. Their existence was confirmed in a further degree.

We talked about the birth of gravitational astronomy, why is it important?

Gravitational waves offer new information. The fact that we have observed massive black holes also proves that the discovery Thursday regardless of verification of relativity, opens a new field of astrophysics. Both observed black holes had a mass equivalent to 30 times that of the sun. It is a surprise to most, it is not expected that such black holes are easy to train, or if we can easily observe them.

It will explain their education, including because such massive stars can not form in regions where there are very few metals. And so the first time, not only we have proved the existence of gravitational waves, but it also has obvious interest results astrophysics. Now it will be the wave.

Alexander Lechenet