A new revolution is just beginning in the field of science based on the instinct of Albert Einstein exactly 100 years ago. For the first time in history we have been recorded so-called gravitational waves: the credit goes to LIGO (Laser Interferometer Gravitational-Wave Observatory), the instrument that allowed to "observe" for the first time the phenomenon. The data were analyzed in collaboration with Virgo, which is located in Casina, in the province of Pisa. Virgo is part of the European Gravitational Observatory (Ego) and is funded by the National Institute of Nuclear Physics (INFN) and the National Council of the French Research (CNRS).
The discovery was announced on Thursday, February 11 by members of LIGO, an experiment by $ 1 billion, 900 scientists and 15 countries, which since 2002 has the sole purpose of tracing the existence of gravitational waves. The first gravitational waves were detected by observing a phenomenon occurred in deep space about 1.3 billion years ago, specifically the collision and its union of two blacks holes. By merging the two entities have released a fraction of a second energy generally produced by the transformation of the mass of only three in pure energy forming subtle gravitational waves. The discovery allows for short to revolutionize the field of physics and observe phenomena with an accuracy up to now virtually impossible.
What are gravitational waves? To understand the concept should understand the space like an invisible fabric that can stretch, shrink or twist in different sizes, including the time is one of them. From here the concept of space-time. Every thing has its own mass, from a planet until you come to a tiny body, how can it be related to a living being, it produces a deformation in this tissue. The larger the object, or rather the more "dense", the greater the distortion. But when two of considerable mass objects move with great speed are able to distort space-time, in some cases with energy sufficient to trigger the ripples. These ripples are gravitational waves, and can be compared to the waves on Earth that causes a speedboat when accelerating on a calm water surface.
This description of gravitational waves was never verified until 1974, when astronomers Russell Hulse and Joseph Taylor have detected a phenomenon comparable to that of two motorboats that they spiral between them. The two objects in space were in this case neutron stars, dead stars and with a considerable mass, formed during a supernova. The two astronomers found that the two stars were in orbit with each other and they would have crashed in about 300 million years. But the energy produced by the process where it would end? The only explanation was based on Einstein intuzioni: distorting the two bodies and their speed space-time in a clear manner, the energy was dispersed in the form of gravitational waves.
The two astronomers won the Nobel Prize a few years later to the discovery of the strange space system, but have never been able to detect and observe the phenomenon of gravitational waves.
How then you were observed gravitational waves? Thanks to LIGO, an experiment using two to form specific detectors L. The first is located in Louisiana, the other at thousands of kilometers away, in Washington state. The tools use a clever trick to see a phenomenon which may in fact not be seen with the naked eye: in the event of distortion of space-time we would not be able to verify this by comparing the distance between two objects, but taking advantage of the light, and in this case the its speed to reach a point in space, we can check if indeed there have been variations in the "fabric".
Each of the LIGO The segment extends for 4 kilometers. A laser beam is divided in the curve of L and bounces toward both of the L segments then join in a detector. Without the presence of a gravitational wave the two formats from the split rays are canceled with each other, and the detector receives no light. In the presence of a gravitational wave, instead, one of the two arms of the laser is reduced, but the other will expand. It is an absolutely imperceptible variation exploiting our senses, but which results in a failure of the laser alignment and consequent reception of light by the detector. This is the signal of gravitational wave presence. If both detectors, located thousands of kilometers away, detect the disorder, then it is easy to see that this comes from space.
According to researchers, the device is incredibly accurate and can detect a change in an object 5mm long 1,000,000,000,000,000,000,000 meters. In other words, it can detect whether the Milky Way has been stretched or compressed to the thickness of a pencil. The LIGO is based on what we might call a trick, but the detection of the last few hours shows that the trick works effects.
Because gravitational waves are so important for the future of astronomy? The researchers said that gravity waves can be used as a tool to study the universe with an accuracy unthinkable only yesterday. Exploiting their presence we can discover phenomena that occurred in the hours before space than is possible with a common telescope because gravitational waves come faster than light. In addition, some phenomena, such as training of blacks holes as a supernova, occur before the core of the star, and not on the surface. Getting a preview of the signal of the occurrence of the phenomenon, therefore, astronomers can point telescopes and other instruments to the source and observe various kinds of processes. It will manage well to study phenomena - such as those who have given birth to our universe and to the Earth itself - in a much more thorough and accurate than today.
Gravitational waves can afford also to understand what happens inside a dying star. A telescope can only show what happens on the surface, but to understand the process behind, his motives, we must "observe" the nucleus, which is the source of life of a new black hole. At the moment the blacks holes can be "explored" only through graphical representations made digitally. Taking advantage of the new discovery, the researchers will also be able to determine how often occur phenomena of this type in the Milky Way. Until yesterday, the science had no idea about the matter, but as observed through LIGO we can guess that they are not so rare and may occur even 2 or 3 times every 100 years.
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