General, Research, Technology

What are gravitational waves. When and how they were discovered

When someone says something about gravitationalwaves, many can only be perplexed 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.

Understanding gravitational waves can give us more than just the waves themselves.

Content

  • 1 What are gravitational waves
  • 2 Where do gravitational waves come from
  • 3 Study of gravitational waves
  • 4 How LIGO works

What are gravitational waves

Roughly speaking, gravitational waves arethese 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 back in 1915, Albert Einstein told about them, 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 the gravitational waves that wererecorded by laser interferometers of the Gravitational Wave Observatory (LIGO), formed from the collision of two black holes, which turned into one large black hole. Recorded gravitational waves on September 14, 2015.

LIGO laboratory operated by the CaliforniaInstitute of Technology and Massachusetts Institute of Technology. Located in Hanford, Washington and Livingston, Louisiana, and funded by the US National Science Foundation

Where do gravitational waves come from?

Interestingly, the event that led to the formation of the fixed gravitational waves occurred about 1.3 billion years agoand the size of the black holes that collided then was only 29 and 36 times the size of our Sun.

The collision of two black holes causes the formation of gravitational waves.

According to the general theory of relativity - areasons not to believe her are becoming less and less - a pair of black holes that revolve around each other, by themselves, emit gravitational waves and spend a lot of energy on it.

The most common myths about gravity. Which of this is true?

The convergence of black holes for collision occursfor 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 a speed equal to about half the speed of light. If we recall the well-known formula, where E = mc2, it becomes clear why so much energy is released if velocity and mass appear in the formula, and even squared.

Study of gravitational waves

The Nobel Prize was even awarded for the study of gravitational waves. Got it Joseph Taylor Jr. and Russell Hulse... In 1976, they discovered a binary system inwhich the orbit of the pulsar gradually decreased over time and at the same time released 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.

What is Einstein’s General Theory of Relativity?

The discovery was not made on the first try.and not 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.

The Big Bang is also called one of the reasons for gravitational waves.

Modernization work was carried out in largea number of research institutes and laboratories from all over the world, including the USA, 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 achieve the result.

At the moment, LIGO is carrying out research using a huge scientific collaboration (LIGO Scientific Collaboration (LSC)). The research team includes over 1000 scientists from universities in 15 countries of the world.

What happens if you fall into a black hole?

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 allowshumanity 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.

The big bang could create a “mirror anti-universe” of our universe

How LIGO works

At the heart of each of the two LIGO laboratoriesuses 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.

If Albert Einstein now, a hundred years after his discovery, saw the results of LIGO research, he would be glad that he was right.

Beams of light are needed so that you cancontrol 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 you about their most interesting discoveries in our Telegram news channel.

Scientists have discovered an unknown source of gravitational waves.

Observatories should be exactly spaceda large distance 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 allowedaccelerate 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.