The LIGO Scientific Collaboration (LSC) has just confirmed that found the first evidence of the existence of gravitational waves. There is no better gift to celebrate the centenary of Einstein's theory than by checking his last great unconfirmed relativistic conjecture. This, undoubtedly, is one of the most important physical discoveries of the century .
As explained by David Reitze , a professor at the University of Florida and executive director of LIGO , gravitational waves that LIGO detected on September 14 were produced by the collision of two black holes with a mass equivalent to 30 soles. During these months, different teams have been dedicated to confirm the discovery. Today, Reitze has started talking saying "Ladies and gentlemen, we detected gravitational waves. We've done it ! "
What happened today?
The rumors have been confirmed. After the announcement, Gabriela Gonzalez, spokeswoman for LIGO and professor at Louisiana State University, explained in detail as the September 14, 2015 were located for the first time in the observatory Livingston (Louisiana) a signal from the Magellanic Clouds, Two small galaxies close to the Milky Way. Seven milliseconds later were detected by the Hanford detector in Washington state. These waves were exactly what we would expect according to the forecasts made Einstein in 1918; Something that has allowed to accelerate the processes of collaboration.
LIGO looks for small variations in the path of several laser beams up to 4km in length: in this case a variation of 1/1000 part of the size of a proton. Something so small that several detectors are needed. In fact, the two detectors are not enough to hear well what happens. Therefore, soon a network of detectors will allow us to hear better what happens out there. A detectors Hanford, Livingston (both USA) and GEO600 (in Hannover, Germany), will soon join VIRGO (Pisa, Italy), LIGO India and Kagra (Japan).
"The signal we detected began so long ago that life on earth was taking its first steps and we have still been able to detect it," said Gonzalez. Specifically, 1.3 billion light years from Earth. Not only that, this finding demonstrates that binary systems of black holes can occur. Something that would already be a great discovery on its own. These black holes have a diameter of about 150km each, about 30 solar masses and collided approximately half the speed of light.
What does this all mean?
Although we have spent these days saying that Einstein postulated the existence of gravitational waves with his general theory of relativity, the fact is that the first time they spoke was a year later. In fact, in that work Einstein was wrong: hoping that the gravitational waves were analogous to the electromagnetic ones of the Maxwel theory, solved the problem affirming that the first ones could not transport energy. In 1918, he came up with the solution, amended the error and enunciated the waves as we know them today. In fact, his description was so precise that when scientists detected the first wave no doubt.
This process gives us an idea of how advanced the ideas of the Judeo-German physicist were. If the theoretical developments of the moment were short, the technological challenges to start them were immense. Find the gravitational waves was, in fact, the last great relativistic guess that was to be confirmed.
For the first time, we can listen to the universe and, for the first time, we have put into operation the technology that will lead us to know what happened in the first 500 thousand years of space-time life. Undoubtedly, the LIGO Collaboration, an international scientific effort that brings together numerous institutes and state agencies, today wrote one of the most exciting pages of the recent history of astrophysics and cosmology. As concluded France Cordova, director of the National Science Foundation "This advance represents more than a new generation of observatories: it represents a new way of looking at the universe ."