Black Holes


By Rohil Bahl


Imagine squeezing the mass of a star 10 times larger than the sun into a sphere as big as a city. Such a region would have super strong gravitational effects and nothing, not even light would be able to pass through it. Naturally, if light cannot escape this body it will not be visible. Such a body is known as a black hole. According to scientists there are millions of black holes in our galaxy.

We know that black holes have a large amount of matter squeezed into a relatively tiny area. But how are such bodies formed? Well, there are 3 main kinds of black holes. The smallest ones are known as primordial black holes. Scientists believe this type of black hole was formed soon after the big bang. It is as small as a single atom but with the mass of a large mountain. The most common type of medium-sized black holes is called “stellar.” A stellar is formed when a massive star collapses in upon itself. Its mass can be up to 20 times greater than the mass of the sun and can fit inside a ball with a diameter of about 10 miles. The largest black holes are called “supermassive.”

These black holes were formed at the same time as the galaxy they are in. Scientific evidence suggests that at the center of every galaxy there is a supermassive black hole. At the center of the Milky Way galaxy a black hole called Sagittarius A is present. Its mass is equal to about 4 million suns and would fit inside a ball with a diameter about the size of the sun.

A black hole

Now, I’m sure you must be wondering that if black holes are invisible how we know they exist. Well, of course, scientists always have a way of figuring things out.  Scientists can see the effects of a black hole on stars and gases around it. Scientific instruments can detect high energy light produced when a star is orbiting a black hole. Also, the gas present around the black hole forms a disc. The molecules of this disc swirl around the black hole, heat up and emit X-rays. These X-rays can be detected from Earth.

I have always wondered what it would be like to actually go inside a black hole. Would it be like travelling on an extremely high speed roller coaster or would it just be a painful experience. Well according to Einstein’s theory of general relativity, a black hole creates a dent in space-time. Due to this, time experienced around and inside the black hole will be different from the time experienced on Earth. Theories suggest that we could go back in time if we were to enter a black hole. That would be really cool. However, this would only be possible if we would actually survive the journey till the inside of a black hole. According to Charles Liu, if we were to go in a black hole our body would resemble “toothpaste being extruded out of the tube”. We would eventually just turn into a bunch of subatomic particles.

So it turns out that although we can time-travel in a black hole, the journey getting there isn’t something I look forward to. But I feel that in the not-too-distant future there will definitely have a way too safely go inside a black hole. After all, when it comes to science, the possibilities are endless.