Gravitational Waves: Spying the “Dark Side” of the Universe

Gravitational Waves: Spying the “Dark Side” of the Universe

On February 11, they announced that for the first time scientists had proved the fact that space itself vibrates. Now they are in anticipation of subsequent discoveries, hidden in the notorious darkness.

The initial discovery of the so-called gravitational waves occurred in September, when a pair of black holes, each of which is about 30 times as thick as our Sun, went spiraling towards each other and then merged into a new, larger black a hole at a distance of 1.3 billion light years.

In the blink of an eye, the collision released a powerful wave of energy exceeding the energy of all the stars in the Universe by 50 times. And it turned out to be so powerful as to slightly jiggle the L-shaped 2.5-mile laser beam on Earth, which represents the heart of the LIGO - Laser Interferometer at the gravitational-wave observatory.

The LIGO Observatories in Louisiana and Washington DC were upgraded at the very time that the discovery was made. Scientists spent a whole month testing the trail of a gravitational wave, which changed the length of the laser beam 10,000 times smaller than the diameter of a proton. At the same time, LIGO continued to control other space shakes.

“Before that, we didn’t even know that black holes exist in pairs,” said David Reitz, a physicist at the University of Florida, now director of LIGO at California Institute of Technology, last week.

“This is the beginning of new astronomy,” added David Schumaker, a physicist at the Massachusetts Institute of Technology.

LIGO detectors collected data for another three months, and then closed the instruments to prepare them for hypersensitivity. Additional findings have not yet been voiced, but Gabriela González, a physicist at Louisiana State University, a spokeswoman for LIGO’s scientific collaboration, hinted to lawmakers that the discovery of merging black holes is not a single event.

“We saw one event in one month ... so that we can only speculate on this data. But we took the information for three months, which are still being analyzed. And everything that we see corresponds to what we saw there, ”said Gonzalez.

“Thanks to theoretical models, scientists expect to be able to detect at least a few gravitational waves per year,” she added.

The union of black holes is not a cosmic event that probably brings vibration to the fabric of space and time.

Scientists hope that LIGO will sense peals of neutron stars, which are the dense remnants of destroyed stars packed in such a way that one teaspoon of such matter weighs about 10 million tons.

As a rule, neutron stars are magnetized and rotating, although this process has not yet been fully explained. They can also exist in pairs, giving scientists the ability to detect not only how gravitational waves interact, but also x-rays, radio waves, and other electromagnetic emissions that they produce.

“We can gather all this information ... and find out more than we could ever have without gravitational waves or without their combination,” said Schumaker.

LIGO will also be able to identify supernova explosions, destruction, cosmic strings, and even what Shoemaker calls “defects” in the interweaving of space and time.

“Of course, surprises await us. Every time we open a window to the universe, we see something new, ”he said. In the meantime, LIGO returns to work this summer or early fall. It can be joined by the first of several scheduled laser interferometers outside the United States.

Virgo — The French-Italian project, located near Pisa in Italy, adds a third ear to detect and test gravity waves in order to pinpoint their sources.

Virgo will also serve as a backup if one of the twin directors of LIGO in the United States is not in place. With at least two detection devices, we get the key to eliminating possible ground-based sources of vibration.

Japan is developing a gravitational wave detector, and last week the Indian government also agreed to promote the LIGO-India project.

Europe has also joined and is testing a space gravitational wave detector called the LISA tracker.

“In space, instead of having a 2.5-mile mechanism (to detect gravitational waves), you can get a 2.5 million-mile mechanism. Our sensitivity grows with the length of this mechanism, ”said Shoemaker.

Since gravitational waves, like electromagnetic radiation, propagate at different lengths, scientists expect that multiple observatories of gravitational waves will be necessary to study various phenomena.

“We are looking at the dark side of the universe, which we know too little about,” said Gonzalez.

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