Black holes are astronomical anomalies; just hearing their name invokes the image of a dark, seemingly timeless void — yet black holes are one of the brightest objects in the universe. Starting from Albert Einstein’s prediction of their existence in 1916 to the recent excitement following a successful attempt by astronomers to photograph a black hole, many have been possessed by the urge to know more about these peculiar creations. So, what exactly are black holes and why are they so special?
Essentially, a black hole is a massive star that has run out of fuel. Stars, despite being able to exist for up to a couple billion years, have a point in time when the amount of hydrogen it contains is inadequate at powering the star’s sheer mass. At this stage, the star expands to become a red giant, and stays this way for up to a billion years until its helium core eventually buckles under the weight of the entity and fizzles out. The red giant, now stretched out to its maximum size, promptly blows up into large chunks known as planetary nebulae, which are then sucked in by the substantial gravitational force of the center of the gaseous being. If the remnants of the star have enough collective mass, they fuse together to become a black hole; alternatively, the red giant could explode into a red supergiant, or cave into itself to become a white dwarf — a very small, dense star — surrounded by thick clouds of planetary nebulae. Our galaxy’s Sun, for example, is destined to become a white dwarf.
In the case of larger stars, such as V616 Monocerotis, the former scenario proves to be the most applicable for their future state. V616 Mon., best known as the closest black hole to our solar system, is located approximately 3000 light years away and has a mass of between 9 to 13 times that of the Sun. Despite being unable to actually see black holes, scientists were able to gauge the approximate location and size of this black hole through observing the behavior of its cosmic neighbor, a star with about half the mass of the Sun. In fact, this method proves effective for most analyses of black holes; the rough whereabouts of black holes can be estimated through evaluating its effects on the trajectories of nearby planets and stars.
There are three major types of black holes: supermassive black holes, intermediate black holes, and stellar black holes. Stellar black holes, as hinted at by their name, form when a large star dies out and leaves an opening with adequate conditions for a black hole to form. Supermassive black holes form the center of most galaxies in the Universe, and with the closest one being more than 27,000 light-years away, they pose no significant threat to our planetary system. Intermediate black holes, which are classified as having a mass greater than those of stellar black holes but less than supermassive black holes, are a complication in the field of black hole-sorting, so much that the scientific community had a field day when the first intermediate black hole was discovered in 2004.
At this point, the question may arise; why are we so invested in learning about black holes when they are literally invisible to the human eye and are too far away to have much of an impact on our planet?
The answer lies in the fact that black holes defy the laws of physics as we know it. In our carefully constructed universe, the behaviors of all substances are governed by a series of defined laws. These regulations, however, go flying out the window when they collide with black holes. In a situation where everything and anything nearby is sucked into a massive hole of light without any indication that they are every released, black holes act as a violent cannonball into a relatively calm surface of scientific logic.
Approximately a century ago, Albert Einstein proposed the theory of general relativity, along with which he theorized that strong gravitational forces could influence the course of light. Black holes are existing proof of this hypothesis, but their gravitational fields are able to do so much more than warping light, an impressive feat in itself; they can warp the very essence of space and time.
So, what exactly happens to objects that are absorbed by black holes? Interstellar director Christopher Nolan seems to think that we end up at the back of a bookshelf. The truth is, we don’t know for sure. The only clear understanding we have about this phenomenon is that space and time cease to exist in the depths of black hole — but what happens to us then? Tentatively assuming that the subject of this experiment has yet to be squashed into a nice serving of cosmic mashed potato, we can only imagine the peculiar fate of a person unfortunate enough to meet such an end. Now, theorizing that observing this occurrence would be possible, what would you see?
BBC reporter Amanda Gefter envisions that an onlooker will experience a phenomenon called spaghettification. This quite appropriately-named, rather unpleasant happening involves the body of the subject, which had previously been accelerating toward the black hole at a rapid pace, slowing down and stretching out to wrap itself around the horizontal boundary of the black hole. As the expanded body of the person nears the black hole, the heat and radiative energy being emitted by the black hole's center cause the spaghettified substance to slowly disintegrate into flakes of ash.
While this traumatizing visualization is gruesomely fascinating in itself, the same happening as seen through the subject’s eyes seems even more intriguing. In the hapless event that the black hole happens to be a stellar black hole, the last moments of said subject — for convenience’s sake, let us call him Bob — would be spent experiencing the agony that comes with being warped into the shape of an elongated, flimsy piece of spaghetti noodle. But granted that the black hole is of a sufficient size, Bob would not feel the spaghettification that an observer would see his body go through; instead, he would feel a weightless sensation, in which he would experience freedom from all gravitational forces. In the somewhat ironic situation of being sucked in by the universe’s strongest gravitational field without being able to feel any of its effects, Bob would continue his journey toward the black hole’s center — an infinitely curved concentration of gravitational forces that would render space and time meaningless — until, upon reaching that point, the existence of Bob as we know it would cease to exist.
This dramatic finale would definitely be a memorable way to end your life — or maybe the scientific logic we have used to reach this conclusion is faulty -just like many physics laws were proven to be when they first collided with the formidable existence of black holes - and the black hole would transfer Bob somewhere entirely new and outside the boundaries of our imagination.
Either way, it is without doubt that the topic of black holes is a mysteriously alluring one; more than half a century has passed since American astronomer John Wheeler first coined the term “black hole” to describe these astronomical entities, yet remarkably restricted progress has been made in understanding just how they work and why they work in the ways they do. And despite the nearest ones being a good few thousand light years away, scientists have continued to be enticed by these black holes.
Although understanding the true, unadulterated experience of being pulled into a black hole may only be achieved by actually undergoing the phenomenon, perhaps through the extensive research being conducted on black holes, we could one day perceive the truth as of what exactly happens when Bob — or any other substance in the universe, for that matter — meets the peculiar fate of falling into the depths of one.
Bibliography
Cain, F. (2016, March 18). Where is the Closest Black Hole? Retrieved from https://www.universetoday.com/127942/closest-black-hole/
Devlin, H. (2019, April 10). Black hole picture captured for first time in space breakthrough. Retrieved from https://www.theguardian.com/science/2019/apr/10/black-hole-picture-captured-for-first-time-in-space-breakthrough
Gefter, A. (2015, May 25). The strange fate of a person falling into a black hole. Retrieved from http://www.bbc.com/earth/story/20150525-a-black-hole-would-clone-you
Parks, J. (2019, July 12). What are intermediate-mass black holes? Retrieved from http://www.astronomy.com/news/2019/07/what-are-intermediate-mass-black-holes
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