When someone says something about gravitational waves, many can only be puzzled and do not understand what it is all about. If you didn't know it, relax – even scientists cannot give a detailed answer to this. Of course, in general, they understand what it is and where it comes from, but blind spots in this story still remain. Even the fact that several years ago they were able to be recorded does not give a detailed answer to the question of what it is. All due to the fact that they appear in distant space and only then reach us. It is noteworthy that Albert Einstein predicted their existence, and modern scientists are only now beginning to approach their solution. Understanding where they come from and what they are, albeit approximate, is very interesting. Let's try to talk about this in a simpler way and without unnecessary complex formulas.
What are gravitational waves
Roughly speaking, gravitational waves are small distortions of space and time. Something like ripples. The reason for their appearance is the events that take place far in space and have truly epic proportions.
The existence of gravitational waves was known for a long time, since Albert Einstein spoke about them back in 1915 , but it is one thing to know, and quite another to prove, show and explain. This is what scientists have been doing for almost 100 years.
It is believed that gravitational waves, which were recorded by laser interferometers of the Gravitational Wave Observatory (LIGO), were formed from the collision of two black holes, which turned into one large black hole. Recorded gravitational waves on September 14, 2015.
Лаборатория ЛИГО работает под управлением Калифорнийского технологического института и Массачусетского технологического института. Находится в городах Хэнфорд, штат Вашингтон, и Ливингстон, штат Луизиана, а финансируется за счет средств Национального научного фонда США
Where do gravitational waves come from?
Interestingly, the event that led to the formation of the recorded gravitational waves happened about 1.3 billion years ago , and the size of the black holes that collided then were only 29 and 36 times larger than our Sun.
If you believe the general theory of relativity – and there are fewer reasons not to believe it – a pair of black holes that revolve around each other already radiate gravitational waves by themselves and spend a lot of energy on it.
Самые распространенные мифы о гравитации. Что из этого правда ?
Collision black holes have been moving closer together for billions of years, but in the last minutes before the collision, their speed increases dramatically. As a result, they are accelerated so much that the collision occurs at about half the speed of light. If you recall the well-known formula, where E = mc2 , it becomes clear why so much energy is released if the formula includes velocity and mass, and even squared.
Study of gravitational waves
The Nobel Prize was even awarded for the study of gravitational waves. It was received by Joseph Taylor Jr. and Russell Hulse . In 1976, they discovered a binary system in which the pulsar's orbit gradually declined over time, while releasing a large amount of energy. They were able to prove that these were gravitational waves. They received the Nobel Prize in 1993 for discovering the pulsar and explaining what is happening with it.
Do not confuse the explanation of the existence of gravitational waves and their detection. LIGO exactly fixed the waves, that is, it proved that all the previous discoveries were not a mistake.
Что такое Общая теория относительности Эйнштейна?
The discovery was not made on the first try or even the first version of LIGO. I had to first carry out the upgrade to the second version, which was much more sensitive. But after the upgrade, gravitational waves were discovered almost immediately, literally at the first launch.
Modernization work was carried out by a large number of research institutes and laboratories from all over the world, including the United States, Europe and even Australia. Initially, funding for the creation of LIGO began in 1992, although for the first time such a project was proposed by a group of scientists back in 1980. Many admitted that it was a big risk , but still believed that they would get the result.
At the moment, LIGO is carrying out research using a huge scientific collaboration (LIGO Scientific Collaboration (LSC)). The group of researchers includes more than 1000 scientists from universities in 15 countries of the world.
Что будет, если попасть в черную дыру?
Many of the scientists who participate in the research consider the discovery of gravitational waves to be the beginning of a new era, since now the field of gravitational wave astronomy has become real.
The discovery of gravitational waves allows humanity to begin researching the deformed parts of the Universe . That is, those objects that are made of the curvature of space-time. The collision of black holes and the traces of this event are only the beginning of a long journey. The main thing is that now this path is open and you can walk along it with a confident step.
Большой взрыв мог создать «зеркальную антивселенную» нашей Вселенной
How LIGO works
At the heart of each of the two LIGO laboratories are L-shaped interferometers 4 kilometers long with laser beams splitting into two beams that move back and forth inside the tube. Its diameter is approximately 1.2 meters and an almost perfect vacuum is created inside.
The light beams are needed in order to be able to control the distance between the mirrors, which are located at different ends of the interferometer. Einstein's theory states that the distance between the mirrors will change by an infinitesimal amount when a gravitational wave passes between them. Distance changes should not exceed one ten thousandth of a proton. They must be fixed. Scientists continue to work in this direction and we will tell about their most interesting discoveries in our Telegram news channel .
Ученые обнаружили неизвестный источник гравитационных волн
Observatories must be exactly spaced apart at a great distance in order to determine the direction of events, which are the cause of gravitational waves. At the same time, you can make sure that the waves came from space and are not associated with local phenomena.
The first observation of gravitational waves made it possible to accelerate the construction of a global network of a huge number of detectors. They allow not only to consolidate the result, but to find even more sources of gravitational waves. In the future, this will indeed open up new opportunities, but for now we have to wait and not interfere with scientists' work.