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Physics
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Black Holes
TOPICAL TERM PAPER
BRITTANY BRUNKER
Black Holes are strange regions where gravity is strong enough to bend light, warp space
and distort time. (Space) They are the cold remnants of former stars, so dense that no matter (not
even light) can escape their gravitational pull. (National Geographic) A black hole is not really a
“hole.” It is anything but. It’s actually a lot of any type of matter packed together into a very
small area. An example would be a star ten times larger than the Sun, squeezed into a space the
size of New York City. (Nasa) Black holes have three layers: the outer event horizon, inner event
horizon, and the singularity. (Space) And they are categorized into Stellar, Supermassive, or
Miniature Black Holes depending on their mass.
Black Holes were predicted by Einstein’s Theory of General Relativity, which explains
that when a massive star dies, it leaves behind a small, dense remnant core. One type of black
hole is produced by Giant stars dying and exploding. If that stars cores mass is at least three
times greater than the sun, the force of gravity overwhelms all other forces and produces a
Supernova. Most stars that become black holes are 10 to 15 times greater than the Sun though.
The crazy thing is, while the star is collapsing, once it hits a certain imaginary surface called the
event horizon, time on the star slows down and as it continues to collapse, time stops completely
which stops the star from collapsing anymore. It basically freezes in time. (Nasa)
If a younger star dies, there is a constant outward pressure that exists in balance with the
inward pull of gravity that is caused by the star’s own mass. That, plus nuclear fusion creates an
energy. Once the star dies though, the remnants of that supernova has no force to oppose gravity
so the star will collapse in upon itself until it shrinks to a zero volume, making it really, really
dense. Even the light from the star is unable to escape the gravitational pull that has occurred.
The stars light becomes trapped, making it dark or “black,” which creates the black hole.
(National Geographic)
The event horizon is the “point from which any escape is impossible because it requires
moving faster than the speed of light.” (National Geographic) Gravity is constant across the
event horizon, which is why light cannot escape the black hole. Planets, light, or any kind of
matter that passes through the black hole’s event horizon are then pulled into the black hole’s
grasp and cannot escape. Black holes don’t suck things in, unlike what most people think.
Suction is caused by pulling something into a vacuum which a black hole is not. It is a ball, if
you will, of a ton of matter. Objects merely fall into the black hole when they reach the event
horizon. Stars can actually be torn apart if they get too close to it. Theory used to imply that if
you fell into a black hole you would stretch out, like spaghetti, and you would die way before
you reach singularity. But a study that was conducted in 2012 suggests that the event horizon
would act like a wall of fire. It would burn anyone who passed through it to death, instantly.
(Space)
In the center of the black hole is the gravitational singularity. It is a one-dimensional
point which contains all the mass in the tiny space. Singularity is where gravity becomes infinite
and space-time curves infinitely. It is also where the laws of physics as we know them cease to
exist. Since singularity is hidden behind the event horizon, where light cannot escape, we don’t
know much about it and maybe never will. (Physics) Because of the Big Bang theory we were
able to study as much as we could about naked singularities, or a singularity that is not enclosed
in an event horizon so it observable from the outside. The Big Bang theory is “a scientific theory
describing the origin of all space, time, matter, and energy approximately 13.7 billion years ago
from the violent expansion of a singular point of extremely high density and temperature.”
(American Heritage) In other words it’s a theory that the universe began with an explosion of
dense matter and is still expanding from the force of it. From that we have learned all that we can
up to this point about singularities.
Because we can’t go near a black hole, or send in anything to research it because we
wouldn’t be able to come back out or receive transmissions from inside of any kind, you may ask
how is it that we even know that black holes exist. A lot of the information comes from
Einstein’s theory of General Theory of Relativity. All the research that has been conducted goes
right along with that theory as it has predicted a number of things, Black Holes, the bending of
light and the Big Bang Theory included. (Physics) Astronomers have confirmed that black holes
do exist by detecting their effect on matter that is near the black hole. For instance, if a star
passes near a black hole, the black hole will pull the star apart as it pulls the star towards itself.
As the star accelerates and heats up while moving toward the black hole, the black hole emits
gamma ray bursts that devours the star; or whatever matter that comes near enough to the black
hole, and eventually that particular matter will cease to exist. (Nasa) One theorist compared
observing black holes to watching a woman dancing with a man in a black tuxedo in a dark
room. You can’t see the man but you can predict that the man is there based off of her
movements. (No Escape)
Scientists are still figuring out how exactly a black hole functions and come up with the
correct mathematical equations. We do know though that black holes exist, how they are born,
why they are different types and even know what would happen if you unluckily fell into one.
Which is not possible though since the closest black hole is light years away but very interesting
none the less. (Hubble Site) There is still so much that we don’t know and we may never fully
understand, but based on the evidence they have found and some very good guesses, scientists
and astronomers have come up with the necessary information on black holes.
BIBLIOGRAPHY
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HubbleSite: Black Holes: Gravity's Relentless Pull. (n.d.). Retrieved April 23, 2015, from
http://hubblesite.org/explore_astronomy/black_holes/home.html
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No Escape: The Truth About Black Holes. (n.d.). Retrieved April 23, 2015, from http://amazingspace.stsci.edu/resources/explorations/blackholes/teacher/sciencebackground.html#1

Redd, N. (n.d.). What is a Black Hole? | Black Hole Facts, Theory & Definition | Space.com.
Retrieved April 23, 2015, from http://www.space.com/15421-black-holes-facts-formationdiscovery-sdcmp.html
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Black Holes, Black Holes Information, Facts, News, Photos -- National Geographic. (n.d.).
Retrieved April 23, 2015, from
http://science.nationalgeographic.com/science/space/universe/black-holes-article/

Black Holes - NASA Science. (n.d.). Retrieved April 23, 2015, from
http://science.nasa.gov/astrophysics/focus-areas/black-holes/
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Singularities - Black Holes and Wormholes - The Physics of the Universe. (n.d.). Retrieved April
23, 2015, from http://www.physicsoftheuniverse.com/topics_blackholes_singularities.html

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2011 by
Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt
Publishing Company. All rights reserved.