Black holes: what would happen if we fell into one of them?

    The most common question about black holes is “what are them?” It is an object in space that has a gravitational pull with so much strength that not even light can escape. This is because it has so much mass contained within such a small volume. Although you may have heard that black holes suck into them everything outside their event horizon, which is kind of like its edge, this is perhaps the greatest cosmic misconception of all. It is very funny and more accurate to think a black hole not as a vacuum cleaner, but as a giant cosmic Cookie Monster. Sure, every cookie in the nearby vicinity will find its way into the area near Cookie Monster's mouth. The cookies get funneled inside towards it. But the overwhelming majority of the cookie matter that approaches Cookie Monster's mouth won't end up getting devoured; instead, it gets spit out in all directions, having been accelerated by a variety of chaotic forces. Black holes are the messiest eaters imaginable.

    

Where does the term “black hole” come from? Many people seem to think that this term was given to these cosmic objects because they do not emit any light, so they are black, and they look pretty much like  a hole when represented in two dimensional space time. Originally, they were referred to with terms like “dark star” or “gravitationally collapsed object”. The term we know these days is traced back to the physicist Robert Dicke who compared these objects to a dungeon in Fort William, Calcutta, called the “Black Hole of Calcutta” where people notoriously entered but never left alive.

The Black Hole of Calcutta, 1756

    So, this raises the question: “What would happen if we fell into a black hole?” We would be spaghettized. And you might be wondering, “what is she talking about?”. Well, the term spaghettification, sometimes referred to as the “noodle effect”, is the vertical stretching and the horizontal compression of objects into thin, long shapes caused by the presence of a non-homogeneous gravitational field. If one were to fall into a black hole feet first, the gravitational pull on their feet would be so much stronger than it would be on their head, causing the person to be vertically stretched. What is more, the right side of the body will be pulled to the left, and the left side of the body will be pulled to the right, causing the horizontal compression mentioned before. Either way, spaghettification leads to a painful conclusion.

    A fun fact is that astronomers have made an estimate on the total number of stellar mass black holes in the entire observable universe, this is black holes that emerged after the death of massive stars. They have estimated that there are around 40 quintillion black holes within that range, and less than 100 have been found in space.