“Scientists have obtained the first image of a black
hole, using Event Horizon Telescope observations of the center of the galaxy
M87. The image shows a bright ring formed as light bends in the intense gravity
around a black hole that is 6.5 billion times more massive than the Sun.”
“…A black hole is a hungry beast: It swallows up everything too close, too slow or too small to fight its gravitational force. With every planet, gas, star or bit of mass consumed, the black hole grows. The edge of a black hole, its event horizon, is the point of no return. At the event horizon, light is drawn in to a black hole, never to escape. And nothing is faster than light…
ReplyDelete“Black holes are stellar tombstones: On July 2, 1967, a network of satellites recorded an explosion of gamma rays coming from outer space. In retrospect, it was one of the first indications that black holes are real. Today, scientists believe that a gamma ray burst is the final breath of a dying star and the birth of a stellar-mass black hole.
“The dramatic transformation starts when a massive star runs out of fuel. As the star begins to collapse, it explodes. The star’s outer layers spew out into space, but the inside implodes, becoming denser and denser, until there is too much matter in too little space. The core succumbs to its own gravitational pull and collapses into itself, in extreme cases forming a black hole. Theoretically, if you shrank any mass down into a certain amount of space, it could become a black hole. Our planet would be one if you tried to cram Earth into a pea…
“To find the darkness, follow the light: Light can’t escape a black hole, so seeing what’s inside one is impossible. Getting a picture of a black hole’s edge is difficult, and getting a clear picture is something else entirely.
“And until now, it has never been done. So far, scientists have detected black holes only indirectly, by their signatures, such as a gamma ray burst, supernova or, perhaps, an object on the brink of a black hole’s event horizon. Typically, if tremendous energy is emanating from a massive core at the center of a galaxy, the core is probably a black hole.
“The Event Horizon Telescope, the one Sheperd Doeleman and his colleagues used to photograph the black hole in the galaxy M87, features a cast of more than 100 scientists on four continents and one very important crystal used to calibrate atomic clocks. In April 2017 scientists staked out eight telescopes atop mountains on four continents, synchronized them, pointed them at the sky and waited. And so they brought Einstein’s monster, the black hole, into view for the first time…”(NYTimes).
https://www.nytimes.com/2019/04/10/science/what-is-black-hole.html