THE INSCRUTABLE BLACK HOLES

A GIANT DONUT IN SPACE. OOPS! SOUTH INDIANS CALL IT AS WADA………….

I am sorry if you have thought that a black hole could be anything but an empty space. Maybe till today, the name ”BLACK HOLE” fooled us. Black holes are the small area where a massive amount of matters are packed within it. For better understanding let us take a star of 10 times more cumbersome than the sun squeezed into a sphere approximately twice the diameter of Chennai. Its unimaginable one. In such a case nothing could escape into it even light because of such a strong gravitational force. NASA scientists have done an incredible masterpiece by capturing the image of such a mystic black hole which leaves everyone puzzled. In my perspective, the black holes are the most fascinating object in space though there are many other interesting objects.

Sir Albert Einstein predicted the actuality of Black Holes by the theory of general relativity. The theory states that when a massive star dies it leaves behind a small dense remnant core. The equation says, if the mass of the core is more than thrice the mass of the sun then the gravitational force overwhelms all other force and produces a Black Hole. It is quite difficult to observe Black Holes with the telescope that detects X- Rays, light and other forms of electromagnetic radiation. The only way to infer the black hole and study is by detecting their effect on other matters nearby.

Even if a black hole passes through the cloud of the interstellar matters it will completely draw the matter inward. This process is called accretion. The same happens when a star passes close to it yet the star gets teared up and accelerated releasing enormous heat and emitting X-Rays into space. Some tantalizing evidence is provided by recent discoveries that black holes have a dramatic influence on the neighbourhood objects emitting powerful gamma rays bursts, devouring nearby stars and spurring the growth of new stars in some areas while stalling it in others.

Earlier, I have said one star´s end is the beginning of a Black Hole. it is applicable only when the star dies in a supernova explosion. However, strange things occur when the star collapses. When the star nears the imaginary surface called ¨Event Horizon¨ the time on the stars shows the relative to the time kept by the observers far away. The time stands still in the event horizon where the star cannot collapse any more. It becomes the frozen collapsing object. The stars like the sun cannot become a black hole because of its smaller size.  

The stellar collision also results in bigger black holes. NASA Swift telescope was launched in December 2004 that observed powerful fleeting flashes of light called Gamma Bursts. Later, Chandra and NASA´s Hubble space telescope collected data from the afterglow event. With the observed data, astronomers concluded that the powerful explosion can result when a black hole and a neutron star collide producing another black hole.

Peppering throughout the universe these stellar mass black holes are 10 to 24 times massive than the sun. Most of the stellar black holes lead an isolated life and are impossible to detect. Scientists have estimated that there would be 10 million to billion black holes in the milky way galaxy.

Scientists have discovered that the closest black hole is a thousand light years far away so we haven´t observed its effect on earth. A supermassive black hole is found in the mid of the milky way galaxy which is 27,000 light years away.

Now its time to explore how the NASA scientists managed to capture the first image of Black Hole.

The depiction of the first image of the black hole

Take a glance over the image, it looks like a dark core encompassed by a flame-orange halo of white-hot gas and plasma. According to the AP report, the equipment that detects wavelengths invisible to the human eye captured the image. This is why the astronomers had added colour intending to showcase the ferocious heat of the gas and dust which is seen as glowing at a temperature of perhaps millions of degrees. Reality is that the black hole might not bear the same look as shown in the released image.

Details of the black hole

The image of the black hole that has been released by the NASA scientists, is positioned in a galaxy known as M87. This is 50 million light years away from the earth. Taking an image of M87’s supermassive black hole at such distance is comparable to snapping a pebble on the Moon. On applying the same scale of compression probably the earth would fit into a thimble. The Sun would measure merely six kilometres edge-to-edge, as per the reports.

Black hole image release date

Two years ago precisely on December 23, 2017, the telescope data was captured. However, completing the image and presenting it before the world involved an enormous effort, including an international team of scientists, supercomputers and hundreds of terabytes of data.

How the black hole image was captured?

Behind every pioneering scientific discovery, there has been a vast quantity of teamwork and years of drudgery that led to the eureka moment. Instead of building a giant telescope, scientists connected many observatories. The eight radio telescopes positioned in Arizona, Hawaii, Spain, Chile, Mexico and the South Pole zeroed in on Sagittarius A* and M87 on April 2017. In the climax, M87 rolled out to be the most photogenic one. Helger Rottmann from the Max Planck Institute, who was involved in the project, said the team waited for data from the South Pole Telescope. However, this came six months later from April due to the harsh climate prevailing during the southern hemisphere winter. The date came on December 23, 2017. It took another year to compile the data to make the image. Three years ago Katie Bouman, an MIT graduate student in electrical engineering and computer science led the development of a new algorithm called CHIRP (Continuous High-Resolution Image Reconstruction) using Patch Priors that helped astronomers to produce the first image of a black hole.

SCI-FI QUESTION THAT WE HAVE ENCOUNTERED ABOUT BLACK HOLE AT LEAST ONCE IN OUR LIFETIME

What if we fell into the black hole?  Say one day you were exploring space looking for a new planet for humans to inhabit, but came across a black hole and decided – Why not check it out? Exactly, like what you watched in the INTERSTELLAR movie. Would you have any chance of survival? How would you get out? Would there be a shortcut to another universe?

Our sun has a gravitational field which is 28 times stronger than Earth´s gravitational field. If you were to walk on the sun, you would be 28 times heavier than you are on Earth. Now, imagine squeezing four suns into something that is just 15 miles (24 km) in diameter, the distance you can cover in a 30-minute drive. What would the gravity be like there?

A black hole´s gravity is so strong, that even light cannot get out. That is why you will never see one but you can detect it from gamma-ray bursts that the hole emits. These bursts, discovered by Stephen Hawking, now carry his name called Hawking Radiation. Stephen Hawking himself believed that black holes can be passages to another universe. So, if you would fall into one, would you find yourself in an alternate dimension? Every black hole has an event horizon, the point at which the gravitational pull becomes so strong that you cannot escape from it. THE POINT OF NO RETURN.

If you found yourself outside of that point, you would see that stars are twisted around a perfect circle of darkness. As you start being pulled toward a black hole, you would be moving faster and faster, accelerated by the force of gravity. That´ś the first bad news for you, brave space traveller. The gravitational force of a black hole is very, very strong. If you fell feet-first, your legs would be feeling a stronger gravitational pull than your head. Your body would be stretched apart. The most common black holes are called ¨Stellar¨. They can stretch about 9 miles (15 km) across and be as heavy as 20 suns. If you happened to be pulled towards a stellar black hole, you would be completely torn apart before you even reach the event horizon. So make sure to choose a supermassive one.

The one that is a million times heavier than our sun. In this case, your body would remain unharmed as you cross the event horizon, as the gravity would be pulling both your feet and your head with almost the same strength. If you are wondering where to find one – you don´t have to look too far. There is one right at the centre of our Milky Way galaxy. Luckily, It is 165 quadrillion miles (or 265 quadrillion km) away from us and will suck neither the sun nor the planets.

But don´t pack your suitcase just yet – crossing the event horizon is just the beginning of the challenge. There is a gravitational singularity at the centre of the black hole, where the density becomes infinite. You will be squashed into the centre and become one with the black hole. You wouldn´t be able to tell anyone about your experience. However, a person observing you outside of the event horizon would see a very different picture. As you were falling into a black hole, they´d see you slowing down, getting dimmer and redder. In the end, you´d just freeze, never crossing the event horizon. This is because space and time in a black hole swap their roles. At the event horizon, the time comes to a standstill, while space, on the other hand, moves forward. You wouldn´t able to turn around and escape the black hole, any more than you can travel back in time. Even when the black hole eventually died, emitting all the particles it had absorbed (including your body), it would be impossible to tell whether those particles were you.

Stephen Hawking, however, found a way, in which the information about your body wouldn´t be lost. He theorized that there are alternate universes with different histories. This means, in one reality you fell into a black hole. In the second one, there was no black hole. It is impossible to be certain from outside of the event horizon whether there is a black hole or not until you fall in there. If you crossed the event horizon and there was a black hole… Sayanora….. But if you happened to be in a reality where the black hole did not exist, you´d still be alive. Just in a different universe. There would be no way for you to get back to ours. Would you dare explore the possibility? Are you drawn to the black holes and the universe? Very soon we will take you on your next hypothetical adventure. Comment your ideas about black holes.  

– Saranya Nagarajan