Black Holes: Mysteries of the Universe
Black holes have the image of being huge and monstrous because of their size and the fact that light "disappears" around them. This image of black holes first came from the ideas of early astronomers, but technology and further research has shown that black holes are much more than monsters that "eat" light. Black holes are complex and without them the universe we have come to know and understand would be quite different, even to the point that our universe might not exist without them. But what exactly is a black hole and why is it so important? To understand black holes it is best to start at the very beginning, when early thinkers tried to explain the world above them, and how technology has had a huge impact on discovering how objects in the universe work.
Black holes have been theorized for years, but it wasn't until modern times that there would actually be proof of such an existence. In 1968, an astronomer, John Wheeler, first termed these mysterious objects as "black holes" (2006 Jefferis). But John Wheeler wasn't the first person to discover that there might be invisible objects in our sky. In fact, in the 1780's, people besides astronomers began to question the possibility of mysterious objects in our sky and what they could look like. One person who questioned what was in the sky was the English geologist, John Michell. Michell believed that some stars, mostly big ones, could disappear from our sight because the gravity around that star would be so strong that it could appear to be" invisible" to us (2006). For a long time many did not look into Michell's idea of invisible objects in the sky because it seemed impossible and silly that such objects could exist. But years later a French mathematician, Pierre Simon de Laplace, looked into Michell's idea and came to a conclusion. Laplace believed that invisible objects could exist, but that it was only possible if it was a star- a star that would weigh 100 million times more than our Sun (2006). Laplace was on the right track on about how the existence of these invisible objects came about, but it would take modern technology to prove and show just how these invisible objects truly came into existence.
Black holes are rather complex and interesting compared to other objects in our universe. The objects were studied at the time were the Sun, the Moon, the many stars, and the start of how planets existed in our universe. These were objects that could seen and study, but black holes were something foreign. Today, modern science has created telescopes that allow astronomers to look deep into space and show some detail of what a black hole is. A black hole is now believed to the last stage of a star's life and this last stage has an impressive finale (2006). First, it is known that a star has heat and gives off light, but when a star becomes a black hole those rules change. What happens to the star is that, since it no longer gives off heat or light, it's gravity keeps pushing strongly inwards (2005 Rau). In a sense, it seems like the star has "eaten" its own light, but it is just the star collapsing in on itself. After collapsing, the star starts to become very dense, so dense that it becomes rather small (2005). In reality, the star's size has changed, but the star still contains all its material it had when it was big- the material has been jammed together, like stuffing an entire closet of cloths into a suitcase. The amount of clothes in the closet hasn't changed, but the closet clothes are now compressed together to fit into the suitcase instead of being spread out in the closet. As the star becomes denser, the gravity becomes much stronger, turning the star into a black hole (2005). But a black hole doesn't become inactive after becoming dense, but instead becomes very active. Now that technology has allowed astronomers to see black holes further studies show the complexity and uniqueness of these invisible objects.
Although further studies have deepened the understanding of black holes, black holes are still somewhat a guess. Telescopes have taken pictures of black holes, but there are only ideas of how a black hole functions since living objects would never be able to survive long enough to gather any information on them. But despite those odds, there have been at least 19 black holes found in the Milky Way (2012, Talcott). That means at least 19 big stars have ended in our solar system, but how did these black holes get detected in the first place? Over the years, astronomers have found ways to detect these black holes and each way is unique. One way to detect black holes is to study binary stars. Two stars that orbit each other are called binary stars and when it appears that these stars are orbiting an empty space it can be assumed a black hole exists there (2005 Rau). Another way to find a black hole is to look for any streams of light or glowing jets coming from a space because it is believed that energy (or gases drawn in to the black hole) gives off light since a black hole cannot give off light (2006 Jefferis). Another question arises after a black hole is detected-what exactly is a black hole and what does it do? Detection has proved that black holes do not give off light, but if there is no light how can a black hole's function be studied? The answer is that a black hole can't physically be studied, but there are ideas that seem to support possible explanations.
A black hole's function can be hard to understand, but there are ways to explain a black hole in an easier way. In the scientific way, a black hole's gravity pulls in objects from around it and any object that goes in it disappears (2006). The center of the black hole (where the gravity pulls in objects) is called a singularity and the singularity is a boundary to the event horizon (2006). An event horizon is very important because that is the last place where light fails to escape (2012 Talcott). It's hard to imagine what a black hole looks like when all these terms are used because these terms don't describe a picture that people can visualize. In the unscientific way, imagine that you are being sucked in by the black hole. At first, you won't notice anything until your feet hang above the center, where the gravity is strongest, and then your head would start to stretch because another force of gravity is starting to pull on you (2005 Rau). Your body will be pulled and stretched from the forces of gravity, like pulling a rubber band from both ends (2005). After that pulling and stretching, you'd be sucked into the black hole and, unless you are faster than the speed of light, you'll disappear forever. This explains why astronomers say that an object that gets too close a black hole disappears not because there is another universe within the black hole, but that the gravity is so strong in the black hole that an object gets compressed and gets sucked in. Even though no person has gone into space to prove this fact about black holes, astronomers have studied the objects around the black hole to know that it is unlikely anything would escape the black hole ever again.
Black holes have not been studied as long as other objects in the universe because technology in early times had not allowed true observation to happen. However, modern times have allowed astronomers to study the sky and get a better understanding of the objects in the universe. Although black holes are not as easy to study they still provide clues of what could become of the universe and the objects that reside in it. Perhaps one day technology will allow us to study black holes and achieve a true understanding of how black holes exist in our universe.
References
Jefferis, D. (2006). Science Frontiers: Black Holes and Other Bizarre
Space Objects. Crabtree Publishing Company, David
Jefferis/BuzzBooks.
Rau, D.M. (2005). Our Solar System: Black Holes. Minneapolis,
Minnesota: Compass Point Books.
Talcott, R. (2012). Black Holes in Our Backyard. Astronomy,
40(9), 44-49. Retrieved from
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