The first ever photo of a black hole?
The current year 2019 may be a real scientific breakthrough in terms of our knowledge of space and the nature of the universe. Astrophysicists believe they have finally found a way to capture one of the most mysterious phenomena in the world known to us – a black hole. The Event Horizon network of telescopes has been collecting data for years, and scientists are now close to providing the public with the first ever telescopic photograph of a black hole’s event horizon.
Given the wide coverage of this phenomenon in popular science media, at first glance it may seem strange that for so much time of research there is not a single reliable photograph of it. But getting acquainted a little closer with the physical nature of black holes, the reason for this becomes clear. The force of gravity they possess is so enormous that nothing can escape, not even light. A black hole absorbs all types of radiation, including X-rays, infrared radiation and radio waves, making it impossible to detect an object directly. But the high-energy radiation created around the event horizon by the movement of matter is quite realistic to detect and, it seems, even to capture in the form familiar to the human eye.
It’s worth noting that back in 1978, a French astronomer named Jean-Pierre Luminet created what could be called the world’s first depiction of the event horizon of a black hole. This, of course, was not a real photograph, but thanks to his knowledge of astrophysics and mathematics, Lumine, using an IBM 7040 computer, performed simulations that gave a rough idea of the phenomenon that was taking place.
“At the time, the study of black holes was quite an exotic form of scientific activity, since most scientists did not take seriously the evidence of their existence.”- said Luminet. But nevertheless, he himself continued to stubbornly search for indirect signs of the influence of black holes on the surrounding universe, which would confirm their reality. It was Jean-Pierre Lumine who first announced the existence of an accretion disk that appears during the absorption of matter and even visualized it.
Using data from a computer, Lumine spent many hours manually drawing ink on photographic paper. The image shows how the black hole’s intense gravity bends light around it. “The bending of light beams also generates a secondary image that allows us to see the other side of the accretion disk on the opposite side of the black hole from the observer,” Lumine said in an article published on arXiv.org last year. With its discovery, Luminet has opened the doors of imagination for many innovators who have depicted their own interpretations of the black hole, both in scientific forums and in world cinema.
Christopher Nolan’s 2014 film Interstellar has been lauded for its scientifically accurate depiction of a black hole, which was created through 3D computer rendering with the direct involvement of American theoretical physicist and astronomer Kip Thorne. However, we should expect that the reality of the black hole event horizon will be slightly different from the picture we saw in the film, where the accuracy of the transfer of the phenomenon gave way to visual appeal and simplification. The characteristic features of the accretion disk are asymmetry, irregular luminescence, and strong distortion of the back side of the disk.
The Event Horizon Telescope will focus on an object called Sagittarius A *, a supermassive black hole at the center of our Milky Way galaxy. The global network of radio telescopes consists of observatories located around the planet, including the South Pole, in the United States, Chile and the French Alps. The results of the EHT research will provide an unprecedented validation of the validity of Einstein’s general theory of relativity.
The Event Horizon Telescope Array operates using a technique known as very long baseline interferometry (VLBI). Multiple independent antennas, forming a huge virtual telescope almost the size of the Earth, allow you to “break” through the clouds of gas and dust of our galaxy, as well as the hot gas surrounding the black hole itself. With so many antennas focused on one location, the telescope’s angular resolution is expected to be a staggering 50 microseconds. In simple terms, this resolution is equivalent to being able to see a grapefruit on the lunar surface.
Based on currently available observational data, the researchers suggest that the black hole at the center of the Milky Way galaxy is probably about 4 million times more massive than our Sun, but with an event horizon of only 20 million km in diameter. They hope that further research will provide a better understanding of the polarization of radiation, the structure of the magnetic field and the relativistic jets of the black hole.
The collected data, which reaches up to 500 terabytes from each telescope, will be processed using a supercomputer in the laboratory of the Massachusetts Institute of Technology. According to rough estimates, scientists will be able to show an electronic image of the event horizon of a black hole in about a few months.