Not many things can mystify the mind like black holes do. When examined in depth, black holes aren’t all that confusing. Thanks to the discoveries of physicists, we have a pretty good hold on what black holes are, and how they function. First, though, one must know the basics of the physics that we apply to black holes.
Gravity is the essence of black holes. Gravity is a well known force, as it has an enormous effect on the earth and everything on it. The factors that effect the force of gravity are the universal gravitational constant, the mass of said planet and the radius of said planet. Therefore, the gravitational force is different on each planet, not taking into account that distance between planets which also effects their gravitational pull on eachother. The force of gravity on earth is equivalent to about 9.8 meters per second squared. That is equal to the acceleration at which objects are pulled back down to earth. As a more advanced way of thinking of gravity, Tia Ghose defines it in What Is Gravity as: “the consequence of the fact that matter warps space-time.”
Now that there is a general understanding of what gravity actually is, lets examine how gravity works within a black hole and what a black hole actually is. Black holes form by the death of stars. When they die, most stars will just form white dwarfs, but the largest of stars will become black holes. These stars will quite literally go out with a bang, exploding and leaving behind nothing but their stellar core. The remnants of the star will then collapse in on itself, thus creating a black hole.
Black holes are essentially invisible on the black canvas of the universe, but their intense gravitation pull and it’s effect on the stars around it gives away the location. Though these elusive beings are depicted as a huge danger to the universe, and to our own planet, there is no need to be alarmed. As National Geographic explains in Black Holes 101, “if our sun was suddenly replaced by a black hole of similar mass, our planetary family would continue to orbit unperturbed, if much less warm and illuminated.” Our own milky way is out of the way of danger of any impending black holes.
The physics that we apply to black holes are governed by Einstein’s field equations. These equations stem from Einstein’s theory of general relativity. Simply, a “black hole,” isn’t a hole at all, but rather a singular point of such large gravitational pull that no object within the event horizon could ever gain enough velocity to escape its gravitational force. The event horizon is, as the author of What is a Black Hole explains, “the last distance from which light can escape the pull of the black hole. Inside the event horizon, everything, including light, must move inward, getting crushed at the centre.” Some theorize that a black hole could be used as a worm hole if entering only the event horizon in just the right way.
The gravitation pull of black holes is so intense that it even warps spacetime. Every mass in space slightly alters spacetime, almost like a dent. Think of spacetime as elastic, the heavier the object, the more of a dent it makes. Planets like earth make a small dent, but it is nothing in comparison to that of a supermassive black hole. This effect can actually be visible, Robert Britt describes and example of this in Einstein’s Warped View of Space Confirmed, “In observations of activity around black holes in 1997, researchers noted that gasses spiraling into the black hole wobbled, or precessed, like a top.” Unusual motions can also been seen of light when entering a black hole. In fact, the entire view of the universe is warped when looking at it from the view of the black hole.
As stated before, though black holes can sound very intimidating, there is nothing to fear. It is common knowledge that the milky way has its very own supermassive black hole at its center, and studies suggest that there are thousands more joining it. Nell Greenfieldboyce states in Center of Milky Way Has Thousands of Black Holes, Study Shows: “Their calculations show that there must be several hundred more black holes paired with stars in the galactic center, and about 10,000 isolated black holes.” These entities though, do not negatively effect the earth because we are lightyears away from their event horizons, and essentially out of danger.
Over the past decades, scientists have made incredible strides researching black holes, and there is plenty more to come. No on can really what is to come of further black hole research, but there is hope that black holes could be an essential piece of the puzzle when explaining how the universe began and how the universe will end. If that is the case, this research could change he course of history dramatically. Scientists are also diving further into the idea of wormholes and harnessing them for the use of time travel. Using Einstein’s rules of general relativity, many have theorized the existence of entities called “white holes.” A better explanation is given by Jessica Krall and Jessica Felhofer in The Future of Black Holes, ” The idea of wormholes first came from the idea of white holes. The equations of general relativity have an interesting mathematical property: they are symmetric in time. This means that you can take any solution to the equations and imagine that time flows backwards rather than forwards, and you will get another valid solution to the equations. If you apply this rule to the solution that describes black holes, you receive a white hole. Since a black hole is a region of space from which nothing can escape, the time-reversed version of a black hole is a region of space into which nothing can fall. So, just as a black hole sucks things in after they pass the event horizon, a white hole would spit these things out.” The future of black holes is more than promising and could mold the future of not just this planet, or the milky way, but the future of the entire universe.
“Black Holes.” Physics For Idiots, physicsforidiots.com/space/black-holes/.
“Black Holes, Explained.” What Is a Black Hole?, 25 Sept. 2018, http://www.nationalgeographic.com/science/space/universe/black-holes/.
Ghose, Tia. “What Is Gravity?” LiveScience, Purch, 3 June 2013, http://www.livescience.com/37115-what-is-gravity.html.
Greenfieldboyce, Nell. “Center Of The Milky Way Has Thousands Of Black Holes, Study Shows.” NPR, NPR, 4 Apr. 2018, http://www.npr.org/sections/thetwo-way/2018/04/04/599437677/new-study-shows-the-center-of-the-milky-way-has-thousands-of-black-holes.
Britt, Robert Roy. “Einstein’s Warped View of Space Confirmed.” Space.com, Space.com, 8 Mar. 2016, http://www.space.com/456-einstein-warped-view-space-confirmed.html.
Krall, Jessica, and Jessica Felhofer. “The Future of Black Holes.” The Future of Black Holes, http://www.felhofer.com/blackholes.htm.