Astronomers have recently discovered a massive black hole lurking in the corner of our Milky Way galaxy. Despite decades of research, these monstrous cosmological phenomena remain shrouded in mystery. It's time to clear some myths...
Black holes do not suck
Thanks to science fiction movies, it’s quite easy to picture a black hole as a cosmic vacuum cleaner, sucking up everything and anything that gets too close to its high-gravity grasp. But reality is totally different. To understand a black hole one should know the concept of ‘event horizon’ — the boundary marking the limits of a black hole. So, it’s only when you cross this point that you will be sucked into the oblivion. It’s similar to the “point-of-no-return” that a boat experiences when approaching a whirlpool and reaching the point where it is no longer possible to navigate against the flow. This is why, if our sun were to be replaced by a black hole weighing the same as our sun, Earth would still travel in the same orbit. But obviously, all life on Earth will came to an end as black holes don’t emit any heat or light.
What are black holes?
A black hole is a place in space from which gravity prevents anything, including light, from escaping. Since no light can get out, no one has ever seen a black hole, and no one ever will. A black hole comes into existence when a star dies. The presence of a hole is deduced by the effect it has on its surroundings. It's like looking out of a window and seeing every treetop bending in one direction. You will rightly come to the conclusion that the bending is caused by a strong gust of wind. Similarly, astronomers observe and measure the unusual or inexplicable movements of stars and clusters of dust and gas around these invisible entities to predict the presence of black holes. Depending on the mass of the collapsing star, a black hole can be big or small. Scientists think the smallest black holes are as small as just one atom. In reality, the largest black holes are called “supermassive,” which have mass equivalent to 1 million suns.
Black holes evaporate over time
Nothing is eternal, not even black holes. In the 1970s, Stephen Hawking made an audacious prediction that black holes evaporate over time, emitting tiny amounts of radiation in the process. This phenomenon is called Hawking radiation, after the famous physicist.
Anything can become a black hole in theory
If you shrunk the sun down to where it is only 3.7 miles across, you would have compressed all the mass down to an incredibly small space, making it a black hole. To turn Earth into a black hole you will have to compress it to the size of a nut. So, technically, anything can become a black hole, as long as it’s compressed enough. But “technically” isn’t the same as “practically.” We know that black holes are formed when a star with a mass greater than about 20 times the mass of our sun collapses on itself.
Einstein didn’t discover black holes
This is the one of the biggest misconceptions about to black holes. Einstein didn’t discover the existence of black holes – though his theory of relativity does predict their formation. In 1915, Karl Schwarzschild, a German physicist and astronomer, was the first to use Einstein’s revolutionary equations and show that black holes could indeed form. From his work derived a term called The Schwarzschild radius – the radius at which a gravitationally collapsing celestial body becomes a black hole. Still, scientists had wondered about the possibility of black holes as far back as the 18th century. English philosopher John Michell mentioned the idea in a report to the Royal Society of London in 1783. But the name “black hole” was first used in 1967, by American physicist John Wheeler.
Black holes will ‘spaghettify’ you
In the movie Interstellar, Matthew McConaughey’s character dives into a black hole and comes out from the other end totally unharmed. But in reality, it’s stranger. If you ever entered one, you would suffer a most horrible death and there won’t be any trace of you! But what exactly would happen? Black holes have this incredible gravitational pull that will literally stretch you into a long spaghetti-like strand. This stretching action is called spaghettification. For example, if you swan dive into a black hole, the top of your head would feel greater gravitational pull than the tips of your toes, which means that you would be stretched longer and longer. Eventually, you will be stretched to the point where you begin to break down into individual atoms.
Not sure if they are portals to another universe
Stephen Hawking has said that black holes could be gateways to another universe. “If you feel you’re in a black hole, don’t give up. There’s a way out,” Hawking said. Experts believe that if you survive the plunge, you might find yourself in another universe on the other side. But there is no concrete evidence to support the claim. Also, taking the plunge would be a dangerous gamble. The incredibly strong gravitational field inside would tear apart every atom in your body.
They slow down time
According to Einstein’s general theory of relativity, time passes more slowly (as seen by an outside observer) in a gravitational field. The prime example is that of the two hypothetical twins, one stays at home, on Earth. The other journeys into space in a spaceship that travelled at nearly the speed of light, before coming back home. Later, when the twins are reunited on Earth, the travelling twin is markedly younger, compared to his/her stay-at-home sibling. The exact age difference depends on how fast the travelling twin was going or how far his destination was. As you reach the event horizon — the point of no return — you are moving at such high speeds due to the strong gravitational force from the black hole, that time will slow down.
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