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Black hole picture revealed for the first time
[NEW YORK] Astronomers announced Wednesday that at last they had seen the unseeable: a black hole, a cosmic abyss so deep and dense that not even light can escape it.
"We've exposed a part of our universe we've never seen before," said Shep Doeleman, an astronomer at the Harvard-Smithsonian Center for Astrophysics, and director of the effort to capture the image, during a Wednesday news conference in Washington, DC.
The image, of a lopsided ring of light surrounding a dark circle deep in the heart of the galaxy known as Messier 87, some 55 million light-years away from here, resembled the Eye of Sauron, a reminder yet again of the power and malevolence of nature. It is a smoke ring framing a one-way portal to eternity.
To capture the image, astronomers reached across intergalactic space to a giant galaxy known as Messier 87, in the constellation Virgo. There, a black hole about 7 billion times more massive than the sun is unleashing a violent jet of energy some 5,000 light years into space.
The image offered a final, ringing affirmation of an idea so disturbing that even Einstein, from whose equations black holes emerged, was loath to accept it. If too much matter is crammed into one place, the cumulative force of gravity becomes overwhelming, and the place becomes an eternal trap, a black hole. Here, according to Einstein's theory, matter, space and time come to an end and vanish like a dream.
On Wednesday morning that dark vision became a visceral reality. When the image was put up on the screen in Washington, cheers and gasps, followed by applause, broke out.
The image emerged from two years of computer analysis of observations from a network of radio antennas called the Event Horizon Telescope. In all, eight radio observatories on six mountains and four continents observed the galaxy in Virgo on and off for 10 days in April 2017.
The telescope array also monitored a dim source of radio noise called Sagittarius A* (pronounced Sagittarius A-star), at the heart of our Milky Way galaxy. There, 26,000 light-years from Earth, and buried in the depths of interstellar dust and gas, another black hole, with a mass of 4.1 million suns, almost certainly lurks.
The network is named after the edge of a black hole, the point of no return; beyond the event horizon, not even light can escape the black hole's gravitational pull.
For some years now, the scientific literature, news media and films such as "Interstellar" and the newly released "High Life" have featured remarkably sophisticated and highly academic computer simulations of black holes. But the real thing looked different. For starters, the black holes in movies typically are not surrounded by fiery accretion disks of swirling, doomed matter, as are the black holes in Virgo and Sagittarius.
Perhaps even more important, the images provide astrophysicists with the first look at the innards of a black hole. The energy within is thought to be powerful enough to power quasars and other violent phenomena from the nuclei of galaxies, including the jets of intense radiation that spew 5,000 light years from the galaxy M87.
As hot, dense gas swirls around the black hole, like water headed down a drain, the intense pressures and magnetic fields cause energy to squirt from either side. As a paradoxical result, supermassive black holes, which lurk in the centers of galaxies, can be the most luminous objects in the universe.
The unveiling, before a crowd at the National Press Club in Washington, DC, and five other venues around the world, took place almost exactly a century after images of stars askew in the heavens made Einstein famous and confirmed his theory of general relativity as the law of the cosmos. That theory ascribes gravity to the warping of space and time by matter and energy, much as a mattress sags under a sleeper, and allows for the contents of the universe, including light rays, to follow curved paths.
General relativity led to a new conception of the cosmos, in which space-time could quiver, bend, rip, expand, swirl like a mix-master and even disappear forever into the maw of a black hole.
To Einstein's surprise, the equations indicated that when too much matter or energy was concentrated in one place, space-time could collapse, trapping matter and light in perpetuity.
Einstein disliked that idea, but the consensus today is that the universe is speckled with black holes waiting for something to fall in.
Many are the gravitational tombstones of stars that burned up their fuel and collapsed. But others, crouching in the centers of nearly every galaxy, are millions or billions of times more massive than the sun.
Nobody knows how such behemoths of nothingness could have been assembled. Dense wrinkles in the primordial energies of the Big Bang? Monster runaway stars that collapsed and swallowed up their surroundings in the dawning years of the universe?
Nor do scientists know what ultimately happens to whatever falls into a black hole, nor what forces reign at the center, where according to the math we know now the density approaches infinity and smoke pours from God's computer.
Any lingering doubts about the reality of black holes vanished three years ago when the Laser Interferometer Gravitational-Wave Observatory, or LIGO, detected the collision of a pair of distant black holes, which sent a shiver through the fabric of space-time.
Since then, other collisions have been recorded, and black holes have become so humdrum that astronomers no longer bother sending out news releases about them.
Now the reality has a face.