Scientists of the European Space Agency, reported on the importance of technological advances, opening the way for practical implementation of the experimental setup to find astrophysical gravitational waves. In February this year the physics of the international collaboration LIGO solemnly declared
of the first in the history of science fixing gravitational waves caused by the confluence of a double black hole system with the masses 36 and 29 solar masses.
The existence of these waves is one of the consequences of the theory of relativity. This is – a subtle effect predicted by theory, but until recently remained elusive to scientists. Einstein showed that any change in the mass of a certain point in space and changes its curvature, and this change is propagated through the universe with limited speed – the speed of light
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As in terrestrial conditions to the LIGO team’s success in catching those waves could not, scientists have long dreamed of an experiment in space, away from all possible sources of disturbance. To conduct such an experiment, scientists want three resting spacecraft separated by 5 million km apart
Remove them from the Earth it is important to eliminate the influence of different noises -. For example, moving of water in the ocean, which can be taken as a source gravvoln.
Gathering in orbit as a giant interferometer, which measures tiny fluctuations spaced test masses, the astronomers hope to not only catch the first gravitational waves in space, but and measure their polarization and to indicate the source.
However, before building in space as a large-scale experiment, the scientists decided to test its viability on a small scale. To this end, in December 2015, the space was sent test mission LISA Pathfinder. Her task was – to demonstrate the fundamental possibility of measuring the distance between the two free-floating in space test masses with the highest accuracy. A special unit has been withdrawn from the Earth at a distance of 1.5 million km in the so-called Lagrange point of the Sun System – Earth
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in fact, the scientists had to create a very peaceful place, though not on Earth, but in space, where the trial of mass-cubes would swim in absolute weightlessness and would not suffer the slightest acceleration. In this case the laser had to help in measuring distances to dice with the highest accuracy. If the experiment failed and the test masses experienced kakie-to disturbance would not be worth the city and a large-scale expensive experiment.
«In the experiment, LISA Pathfinder, we have created a very quiet place, known to mankind .
The results were impressive, they greatly exceeded our expectations, “- said Carsten Dantsmann, director of the Institute for gravitational physics Max Planck Society. – Just to eliminate and minimize the impact of all sources of disturbances, we were able to observe the perfect fall of bodies. And it shows that we can build the LISA, a space observatory to search for gravitational waves »
Success in creating a very quiet with the disturbance point of view of the place is confirmed by the numbers:. It was found that during the first two months of the experiment
relative acceleration of test weight does not exceed 10 -16 of gravitational acceleration.
space mission results are published in the journal Physical Review Letters .
in the running space probe LISA Pathfinder, there are two identical cube of gold and platinum, floating freely in special chambers to protect them from the effects of the solar wind. A laser interferometer allows to measure with high precision the position, orientation and distance between the cubes
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«Measurements made by this first space interferometer, were much more accurate than we expected. We were able to measure the distance between the two freely falling test masses with precision,
exceeding the size of an atom “- said the participants in the experiment Gerhard Heinzel
According to the professor of the Physics Department of Sergei Vyatchanin Moscow State University, included in the collaboration of the LIGO, a successful registration gravvoln under terrestrial conditions are not detract from the value of future space experiment
«space and ground -. they are different projects. Space is guided by infra-low frequencies – at least in the 10 -3 Hz. And the theory predicts that the amplitude of gravitational waves at these frequencies should be greater. Such low frequency in the world can not be fixed due to the seismic. That is why the sensitivity of the LIGO at these frequencies decreases sharply, rests on the so-called seismic wall – Vjatchanin said “Gazeta.ru”. – It’s great that it was announced, in fact there were serious doubts that it will be possible to build the satellite, free from demolition, it was a tough task »
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