Essay PreviewMore ↓
Black holes are one of the more interesting topics in astrophysics. Even though they are commonly accepted as being real, their actual existence has yet to have been proven2. Black holes are objects that have such a concentration of mass that nothing can escape their gravitational pull once it crosses the black hole's event horizon or Schwarzschild radius. The Schwarzschild radius is the radius where, for anything inside, the escape velocity is greater than the speed of light. Since the speed of light is the maximum possible velocity, nothing escapes from a black hole. They are given their name from the fact that they do not emit any light, since light is also pulled into them.
The term "black hole" was first introduced in 1971 by John Archibald Wheeler1. The actual phenomena the term describes was theorized to exist back in 1916 by Karl Schwarzschild. Then, it was just a curiosity as a possible solution to Einstein's general theory of relativity which described gravity as a curvature of space-time2. It wasn't until 1939 that Oppenheimer and Snyder seriously considered the possibility that massive stars could collapse and become what is now called black holes at the end of their lives.
Today, black holes are a commonly accepted theory that even the average person has some idea of what they are. There was even a recent Associated Press story about two black holes in the NGC6240 galaxy that scientists predict will someday merge.
Black holes have many interesting properties. The most obvious from their name is the fact that they can't be seen since no light is emitted from them. One of the ways they can be detected is by the x-rays given off by the matter being pulled into them before it crosses the Schwarzschild radius. As the matter is pulled in, it gains kinetic energy, heats up, ionizes, and when it reaches a few million Kelvin, emits x-rays3. Black holes can also be detected by the way nearby objects are affected by their immense gravity.
As you get nearer to a black hole, light begins to be bent toward it. Black holes have a radius around them that forms what is called the photonsphere. At this point, photons of light can actually orbit the black hole4.
How to Cite this Page
"Black Holes." 123HelpMe.com. 21 Nov 2019
Need Writing Help?
Get feedback on grammar, clarity, concision and logic instantly.Check your paper »
- Black holes - the strange scientific phenomenon that has astounded physicists and astronomers alike for decades. Popular subjects in science fiction novels, black holes are one of the greatest enigmas of the scientific world. Even today, the concept of a super-dense ball of matter that not even light can escape from is somewhat farfetched, and many scientists disagree with each other about nearly every aspect of a black hole. This project will attempt to shed some light on these mysterious formations, and will inform you the reader of the most popular and widely accepted theories surrounding them.... [tags: physics space black holes]
841 words (2.4 pages)
- Introduction Black holes are one of the more interesting topics in astrophysics. Even though they are commonly accepted as being real, their actual existence has yet to have been proven2. Black holes are objects that have such a concentration of mass that nothing can escape their gravitational pull once it crosses the black hole's event horizon or Schwarzschild radius. The Schwarzschild radius is the radius where, for anything inside, the escape velocity is greater than the speed of light.... [tags: space black hole]
531 words (1.5 pages)
- When a star "dies" it can do many different things. It can form a neutron star, expand to a red giant and shrink into a white dwarf, or sometimes collapse upon itself to form a black hole. This is mostly dependent on the density of the star. When massive stars, those twenty times the mass of our Sun or more die, they must either exhaust all of their excess mass or implode upon themselves and form black holes. Gravity overwhelms even the nuclear forces. The gravitational force becomes so strong that nothing can escape it, even photons of light, hence the name "black" hole.... [tags: physics science black hole]
717 words (2 pages)
- Stars, comets, planets, they are all visible when you look up past our atmosphere. What if I told you that there were objects up there that you could not see, but had more gravity than an object 500 time larger than our sun. Objects, that are capable of swallowing whole planets within a split second of time. An object that would steal light right out of thin-air. These objects are more powerful than anything man made. Black holes are the most popular unknown object in science. A black hole is an area of space that has so much mass crammed in it that there is no way for an object to escape its gravitational pull.... [tags: Black Hole Essays]
467 words (1.3 pages)
- The theory that black holes have existed is not new at all. The thought of them first started in 1783 when Rev. John Michell applied Newton’s theory of gravity to predict the possibility of so-called “dark stars.” Albert Einstein’s theory of relativity predicted in 1915 “Schwartzschild singularities.” In 1967, these were renamed “black holes.” A black hole is collapsed object (usually a star) that has become invisible and has such a powerful gravitational force that nothing, even light, can escape its surface.... [tags: essays research papers]
1073 words (3.1 pages)
- In 1916, the German astronomer Karl Schwarzchild attempted to theorize how a star could shrink to become what he called a "Black Hole". Schwarzchild predicted that our sun would have to shrink to less than two miles in radius. He also predicted that even though the sun had shrunk its mass and weight would remain the same, which means that the planets would continue on their orbits, uneffected. Schwarzchild still questioned if stars could become this compact. In 1934 W. Baade and F. Zwicky predicted that the collapse of a star, strips the atoms of their electrons, thus making it a Neutron Star.... [tags: science physics space]
1016 words (2.9 pages)
- Black Holes Every day we look into the night sky, wondering and dreaming what lies beyond our galaxy. Within our galaxy alone, there are millions upon millions of stars. This may be why it interests us to learn about all that we cannot see. Humans have known the existence of stars since they have had eyes, and see them as white glowing specks in the sky. The mystery lies beyond the white glowing specks we see but, in the things we cannot see in the night sky such as black holes. Before I begin to speak about black holes, I will have to explain what the white glowing specks in the sky are.... [tags: Space Astronomy Essays Papers]
1549 words (4.4 pages)
- If theories of their existence are true, black holes are the most powerful force in the known physical universe. Many people are familiar with the term black hole, but few people actually know anything about them. A black hole forms as a result of a massive star running out of fuel to burn (Chaisson, 193). Once the star is no longer exerting outward force by burning off gases, it begins to collapse under it’s own intense, inward gravity (Chaisson, 193). It is like slowly letting the air out of a balloon.... [tags: essays research papers fc]
1456 words (4.2 pages)
- Black Holes Within our galaxy alone, there are millions upon millions of stars. Within our universe, there are millions upon millions of galaxies. Humans have known the existance of stars since they have had eyes. Although interpretations may have differed on what they were, they were always thought of as white glowing specks in the sky, but the mystery does not lie within what we can see, but what we can not see. There are billions of stars lighting the darkness of our universe, but the question lies in what happens when one of these enormous lamps burns out.... [tags: essays research papers]
1038 words (3 pages)
- Black Holes Black holes are objects so dense that not even light can escape their gravity, and since nothing can travel faster than light, nothing can escape from inside a black hole. Loosely speaking, a black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull. Since our best theory of gravity at the moment is Einstein's general theory of relativity, we have to delve into some results of this theory to understand black holes in detail, by thinking about gravity under fairly simple circumstances.... [tags: essays research papers]
3671 words (10.5 pages)
Another interesting property is that for an outside observer, nothing ever appears to enter the black hole. As things get closer to it, the light takes longer and longer to get back out, making the object appear to be slowing down, until at the event horizon, it takes infinitely long for the light to get out and so you can never see it enter.
1 McIrvin, M. (1995). What is a black hole, really?. http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/black_holes.htm
2 Black Holes and Beyond (1995). http://archive.ncsa.uiuc.edu/Cyberia/NumRel/BlackHoles.html
3 Lochner, J. (2002). Black Holes. http://imagine.gsfc.nasa.gov/docs/science/know_l2/black_holes.html
4 Degennaro, S. (1996). The Search for Black Holes. http://www.owlnet.rice.edu/~spac250/steve/
5 McIrvin, M. (1995). Frequently Asked Questions (FAQs) on
Black Holes. http://www.phy.mtu.edu/bht/bh_pub_faq.html