You must have recently seen a photo of what NASA calls a black hole at the center of the M87 galaxy. This was the first-ever image of a black hole taken from Earth, and the Event Horizon Telescope received credit for taking the picture in 2019. What exactly is a black hole, though, and why should we be afraid of it? The simplest explanation is that a black hole can suck the life out of anything that comes into its event horizon–the point of no return. Not even light can escape it.

Why do black holes exist?

Black holes are incredibly dense objects with so strong a gravity pull that literally nothing can escape it. They are formed after a supermassive star loses its gas and collapses upon itself. Black holes can’t technically be seen, but because a hot disk of materials encases it, its location can be determined. As gravity is too strong in black holes, physics and time do not apply to it, which has fascinated scientists for the longest time.

It has become a hot topic lately that half of the 2020 Nobel Prize in Physics was given to scientists working on them. For example, Roger Penrose’s mathematical work showed that black holes were an inescapable consequence of the theory of gravity first posited by Albert Einstein. Meanwhile,  Reinhard Genzel and Andrea Ghez received credit for discovering that a massive black hole is sitting in the center of this own galaxy.

So should people be afraid because of the existence of black holes? Scientists have clarified that there are inactive black holes and active ones, much like a volcano. The ones that are active are those eating up nearby stars and planets. When this happens, the glow emitted by the surrounding area is bright and outshines the entire galaxy, making them quasars. If a person ever falls into a black hole, though, Stephen Hawking suggested he would experience “spaghettification”, where that person’s bones, ligaments, muscles and molecules would be separated–a great degree of pain, for a split second.

Given the peculiar nature of black holes, there was once skepticism in the scientific community about its existence in the galaxy. Even Einstein incorrectly said that black holes can never form. The first black hole ever confirmed was Cygnus X-1 in the Cygnus constellation. After its discovery, 50 more followed. The Hubble Telescope has shown that all galaxies host black holes at their centers, with bigger ones being home to bigger black holes.

Once a black hole has formed, it would continue to absorb surrounding gas and matter from its surroundings. It can even eat up stars and merge with other black holes. The biggest black hole that has been discovered so far weighs 40 times that of the sun or roughly 20 times the size of the solar system. If it is any comfort, humans who fall into a massive black hole will likely survive compared to those that would be sucked into by a denser, smaller black hole. This is because its stretching force is weaker. The bad news? Once you are inside the event horizon — that boundary or point of no return, there is really no turning back.

In the future

Stephen Hawking hypothesized that black holes evaporate slowly and that in the far future of the universe, long after the stars have exploded or imploded, black holes would be the last surviving objects. Hence, there is that fascination from scientists in discovering and studying the properties of these massive black holes.

There are still many questions surrounding black holes, such as whether information is truly lost when sucked by a black hole as it would violate the conservation of energy law. This calls for more investments in research and observation so that these answers would be revealed someday.

Photo Sources:

Cover – NAOJ / / Christopher Crockett,

Photo #1 – YouTube / Nobel Prize,

Photo #2 – NASA/JPL-Caltech via C/net,

Photo #3 – NASA/ESA/STSci/ via Vox