Stephen Hawking had famously said, “In space, no one can hear you scream; and in a black hole, no one can see you disappear.”
BLACK HOLES – Don’t let the term fool you. These are anything but empty spaces. They are points in space having a great amount of matter in a very small area. Having an ability to spaghettify anything that ventures too close; be it a star, a planet or spacecraft – they will be stretched and compressed putty in a theoretical process known as spaghettification. This idea of a matter so dense and compact in a small area has been knocking on the great minds of Scientists for centuries. Einstein’s theory of general relativity showed that when a massive star dies, it leaves behind a small, dense remnant core which is heavily dense and compact. Considering the core’s mass is more than about three times the mass of the Sun, the equations showed that the force of gravity saturates all other forces and produces a black hole.
In totality, there are four types of black holes namely – stellar, intermediate supermassive and miniature. Stellar death is the most common way by which a black hole forms due to the death of stars which are at least 10 to 20 times more massive than our own Sun. As they reach the end of their lives, they slowly lose their mass and deflate and become white dwarfs. They are destined to have two fates – either super-dense neutron stars or stellar mass black holes. Although we have been studying black holes for a very long time, they were more of a mathematical curiosity rather and it’s more of a Herculean task. This is because they are notoriously hard to see and their gravity is so extreme that nothing can escape from it. Earlier, we could not observe black holes with telescopes that detect x-rays, light, or other forms of electromagnetic radiation directly. However, the presence of black holes was inferred and studied by detecting their effect on other matter residing nearby. Accretion is one process where if a black hole passes through a cloud of interstellar matter, it will draw matter inward. The same happens if a normal star passes close to a black hole where the black hole can tear the star apart as it pulls it toward itself. There is tantalizing evidence that black holes have a dramatic influence on nearby environment – emitting powerful gamma-ray burst, consuming nearby stars, and stimulating the growth of new stars in some area while halting it in others. As the attracted matter speeds up and heats up, it emits x-rays that radiate into space. Most black holes betray their locations time and again.
Another interesting fact of black hole is their boundary called the Event Horizon. It is that particular place where the gravity is so immense that it drags the light back and prevents it from escaping.
Now the ground-breaking news is that on the astronomers have captured the first image of a black hole. This breakthrough image was captured by Event Horizon Telescope (EHT). This is a network of eight radio telescopes covering locations from Antarctica to Spain and Chile showcasing an effort involving more than 200 scientists. The EHT picks up the radiation emitted by particles within the disc that are heated to massive temperatures as they swirl around the black hole similar to the speed of light, before vanishing down the plughole. The EHT image displays the shadow of M87’s black hole on its accretion disk. It unveils for the first time a dark abyss of one of the universe’s most mysterious objects which appears as a fuzzy, asymmetrical ring.
This marks a humungous event in the history of mankind where we have seen what we only considered a mathematical presumption. We were expecting to see a blob but in turn, we see a ring which is the best outcome that we could have had. By 2020, there will be more observatories namely – The Greenland Telescope, the Kitt Peak National Observatory outside Tucson, Ariz., and the Northern Extended Millimeter Array (NOEMA) in the French Alps will join EHT in 2020. These could allow the team to extend the image, to better capture the jets that spew from the black hole. The researchers also plan to make observations using the light of slightly higher frequency, which can further sharpen the image. Plans and expectations are endless. This is just the beginning of something really astonishing.
The message of this entire set up is that black holes aren’t as black as they are painted to be. It is possible to fall into a black hole and come out in another universe. Hence they are not those place solitary confinements they were once thought of. There’s always a way out. Nothing is forever dark and unattainable.