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Trent Sigmund
Joy Corwin
Comp & Rhetoric I
30 September 2015
Black Abyss
Black holes make up some of the most mysterious objects in space. Black holes go around our way of thinking by generating mind­bending illusions and defying physics. They possess different laws that to any ordinary human being would seem impossible. Since their discovery, scientists conduct experiment after experiment trying to unlock their greatest secrets.
Bundles of information has been discovered about these dark, massive holes in space, but even the greatest minds in the world can not debunk them.
The idea of black holes appeared in the eighteenth century by John Michell and
Pierre­Simon Laplace, but the term black holes did not come until 1969 by an American physicist John Wheeler. John Michell and Pierre­Simon believed that if an object in space fit the size and density criteria, it would then have a gravity so strong that nothing could escape its pull
(
“How Do We Know That Black Holes Exist?”)
. For example, if you live on Earth, you would need to travel at least seven miles per second to escape its gravity, but if you dwell on the sun you would need to travel 380 miles per second to escape its gravity. Black holes get so large and dense that an object would need to travel faster than the speed of light to escape it ("Black
Hole,"
UXL Encyclopedia of Science
). As of today nothing can travel faster than the speed of light, so if you get too close to a black hole, goodbye.

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Black holes form only when stars two to three times the mass of our sun die and create a supernova. As a star’s nuclear fusion, the bonding of hydrogen atoms to create energy, fails; it can no longer control its gravity and starts to collapse on itself. The point where all of its mass gets compacted is called a singularity. The singularity spawns the point where pressure and density act infinitely ("Black Hole," orld of Scientific Discovery
W
). Any object can become a black hole only if its physical radius obtains a smaller value than its Schwarzschild radius
(
"Schwarzschild Radius | COSMOS")
. The Earth could become a black hole if it could shrink down to the size of a peanut. Spacetime curves when black holes form creating the event horizon. The event horizon acts as the point of no return. Anything that crosses the event horizon can never escape because of the tremendous gravity ("Black Hole,"
Gale Student
Resources in Context
). Some theories state that once black holes form they can never go away because nothing can escape them, but this proves false. When black holes suck up matter, they emit radiation causing them to lose mass and eventually evaporate (
“How Do Black Holes
Evaporate?”)
. All the matter that sits inside of them converts into energy and disperses back into space. Scientists can’t directly observe black holes because light cannot escape them. Instead, scientists have to look at other objects around them. They have a couple ways of doing this. They use X­ray telescopes to observe emissions of radiation swirling around the black hole. The first evidence of a black hole, Cygnus X­1, exists as part of a binary star. A binary star consists of a pair of stars that orbit each other. Cygnus X­1 emits large amounts of X­rays thought to be the result of its unseen companion star ("Black Hole,"
UXL Encyclopedia of Science)
. Researchers can also observe black holes by looking at objects around them. Our sun's gravity affects where

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we see distant stars that form behind it. Black holes affect objects in space a different way.
Objects can appear distorted, creating smears and smudges. So, as a star passes behind a black hole, the light from the star creates a circular smudge and appears black in the middle. This observation of light affected by the black hole is called gravitational lensing (Redd). In the image a galaxy thousands of light years away passes behind the black hole. In Figure 1 the galaxy’s light contorts around the black hole creating a ring of light ("Picture Album").
Figure 1

“Picture Album: Light Echo From Star V838 Monocerotis ­ April 30, 2002.”
HubbleSite ­
. Web. 12 Oct. 2015.

What would happen if a person manages to fall into a black hole? Obviously, we can’t send a human anywhere near a black hole at the time, but that does not mean we can’t hypothesize what would happen if we did. Knowing that black holes bend light, theoretically when a person enters the photon sphere, the area of a black hole where light can sustain an orbit, he/she could see the back of his/her head. This occurs because the light from the back of your head travels all the way around the black hole and back to your face. Also, according to Nola
Redd, a human venturing feet first into a black hole would experience a strong gravitational pull.

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The gravity at the person’s feet would be greater than at the top of his/her head. This results something called spaghettification. The person’s body would stretch out to enormous lengths. No one could survive such strain on their body therefore ending his/her journey into the black hole.
For a person watching another human enter a black hole it would look much different. When the person heads towards the black hole, you imagine that he/she would travel faster because gravity increases as you get closer to the singularity. What actually happens is the opposite. The person would start to get slower and slower until he/she reach the event horizon. This happens because the gravity closer to the event horizon starts to effect time by making it go by slower. Once he/she reaches the event horizon he/she comes to a complete stop. Soon he/she starts to fade away and become red­shifted ("Event Horizon"). By then you will never see that person again because as mentioned before only something going faster than the speed of light can escape.
Those effects will only take place in smaller black holes. Only three types of black holes we can identify exist: stellar black holes, supermassive black holes, and intermediate black holes.
Intermediate black holes prove difficult to locate, and astronomers have only made recent discoveries of them. Scientists believe they could occur when stars in a cluster collide. Stellar black holes populate most of the universe. They form when stars greater than three times the mass of the sun die and collapse on themselves. They stand as the smallest of all the black holes, but they can increase mass by collecting dust and other matter. Supermassive black holes may not have the numbers on stellar black holes, but they dominate. They reach millions and billions the mass of our sun. Scientists can not really prove how they form, but they believe that the black holes can form when hundreds of tiny black holes merge, or when a stellar black hole secretes a

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large amount of matter (Redd). Black holes make our sun look like the size of a baseball. Some people can not wrap their heads around the idea of such a large object.
Supermassive black holes lie in the center of every galaxy, according to scientists at
NASA. Objects called quasars have confirmed this theory. When a supermassive black hole accretes massive amounts of matter, the matter heats up to millions of degrees causing a spill of radiation and light, and that generates a quasar. With enough resources, quasars can be the brightest objects in space ("Quasar"). The only way something produces that much energy is with a massive black hole, furthering the credibility of the theory. A supermassive black hole lies in the center of our own galaxy, the Milky Way. Right now, no matter surrounds the black hole, leaving the space around it dark and without a quasar, but a time could come when matter finds its way back to the black hole.
Black holes hold the key to unlocking some of the universe's greatest mysteries. At one time people did not know they exist, but so much research has gone in to explore these objects that we now know a lot about them. With all the time and effort put forth by scientists and explorers, we can paint a proper picture of them. Who knows what more we could unlock with the information circulating within them? The more we discover, the more we learn about the universe and its secrets. With advancements in technology, we can get closer and closer to discovering those truths about the universe.