Essay/Term paper: Black holes

Essay, term paper, research paper:  Medicine

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. Once the star is compacted to
a certain size, while it"s mass, or weight, remains
the same, it"s gravity becomes so powerful that
nothing can escape it (Hawking, 87). This critical
size to weight ratio is known as the Schwarzchild
Radius (Hawking, 87). Once a black hole is
created in this way, an invisible area, or line
around it exists. If any object crosses this line, it
can no longer escape the gravitational force of the
black hole (Hawking, 87). This line is called the
event horizon (Hawking, 87). If black holes are
proven to exist, beyond theoretical physics, then
they would probably be a very common anomaly
in this universe. In 1915, Albert Einstein put forth
the first real proposition of such an anomaly in his
"Theory of Relativity" (Bunn, Black Holes FAQ).
In the 1930s, three physicists, doctors Volkoff,
Snyder and Oppenheimer, were able to prove the
validity of black holes mathematically. Since then,
black holes have become a very important and
integral part of science and the over all
understanding of the universe. It has been proven,
mathematically, that black holes have infinite,
gravity based, escape velocities and an immense
effect on light, time and even the very fabric of
space. All bodies in space have gravity. According
to Einstein"s "Theory of Relativity", this is because
bodies with a large mass, or weight, actually warp
space (Chaisson, 77). For example, if a two
dimensional sheet of cloth, stretched and
suspended at four corners, represents space, and
a bowling ball is placed in the center, the sheet will
warp downward. If a golf ball is then set at the
edge of the sheet and allowed to move freely it will
be attracted toward the bowling ball, unless the
golf ball is traveling at a speed great enough to not
be effected by the curve. This critical speed is
known as an escape velocity. This is the speed at
which an object must travel to escape a body"s
gravitational force (Chaisson, 77). If a body is
compacted, such that it"s weight stays the same
but it"s radius, or size, becomes smaller, it"s
escape velocity increases in parallel (Chaisson,
196). The simple formula for this, in physics, states
that a body"s escape velocity is equal to the
square root of it"s mass, divided by it"s radius
(Chaisson, 77). For example, if a body"s mass is
two-hundred, and it"s size is twelve and one half,
the escape velocity would be four. If the size of
the same body is reduced to two, while it"s mass
remained at two-hundred, the escape velocity
increases to ten. Since a black hole"s size is
always decreasing and it"s weight is always the
same, the escape velocity is infinite (Chaisson,
195). This means that nothing can escape a black
hole past the event horizon, not even light. Light is
made up of waves and particles. It was
discovered, in 1676, by Danish astronomer, Ole
Christenson, that light travels at a very high, but
finite speed (Hawking, 18). These properties of
light govern that it must be subject to forces of
nature, such as gravity. Light travels at such a high
speed that it is not observably effected by gravity,
unless that gravity is very strong. A black hole"s
gravity is powerful enough to trap light because it"s
escape velocity, being infinite, exceeds the speed
of light (Hawking, 82). This is why a black hole is
black. Once light crosses the event horizon it is
drawn into the hole in space. Although the light is
still hitting objects, it is not able to bounce off to
indicate their existence to an observer, therefor the
black hole appears as a void in space. Closing in
on the edge of the event horizon, light travels back
to an observer at a slower and slower rate, until it
finally becomes invisible. This is due to heavy
gravity and the effect that a black hole has on time
(Bunn, Black Holes FAQ). According to
Einstein"s "General Theory of Relativity", time is
not a constant (Hawking, 86). Time is relative to
an observer and his or her environment (Hawking,
86). It has been proven that time moves slower at
higher speeds (Hawking, 86). An experiment was
conducted in which two synchronized atomic
clocks were used. One was placed in a jet and
flown around the Earth at three times the speed of
sound, while the other was left stationary, on the
ground (Hawking, 22). When the jet landed and
the clocks were compared, the one in the jet
displayed an earlier time. This leads to the
reasoning that time is just as volatile as light or dirt.
In cosmology, a singularity is an event or point that
has a future or a past, but not both (Hawking, 49).
In human life, death would be considered a
singularity. A black hole is also considered a
singularity. If an object crosses the event horizon
of a black hole, it relatively ceases to exist, it has
no future (Hawking, 88). Absolutely nothing in the
known universe can survive in or escape from a
black hole, so it can be said logically that time is
stopped within the event horizon. The only way for
an object to escape this fate would be for a
strange anomaly to occur in the fabric of space,
caused by a theoretically different type of black
hole. If the mathematics that describe a black hole
are reversed, the outcome is an object called a
white hole (Bunn, Black Holes FAQ). As the
complete opposite of a black hole, a white hole is
an object into which nothing can fall and objects
are only spit out (Bunn, Black Holes FAQ). At
this point, white holes are strictly theory. Their
existence is highly improbable. If certain
properties, such as motion or a positive or
negative charge are applied to a black hole, then
the possibility of a white hole forming within the
event horizon arises (Bunn, Black Holes FAQ).
This leads to an even more improbable occurrence
called a wormhole (Bunn, Black Holes FAQ). In
theory, a wormhole would truly be a tear in the
fabric of space. Since time essentially has no effect
on a black or white hole, if an object were to fall
into a worm hole, it could conceivably be spit out
anywhere in time or space (Bunn, Black Holes
FAQ). If an object falls into a black hole, which
has undergone the transformation into a wormhole,
it could probably avoid hitting the singularity
(Bunn, Black Holes FAQ). Therefor it would not
be turned into spaghetti and compacted to the size
of a base particle. Instead, it would follow the
closest thing to a straight line that it could find,
which would be to slip completely through the
wormhole (Bunn, Black Holes FAQ). It sounds
impossible, but it looks good on paper. If
wormholes could exist, according to calculations,
they would be highly unstable (Bunn, Black Holes
FAQ). If anything were to disturb it, like an object
passing through it, it would likely collapse (Bunn,
Black Holes FAQ). Though the equations are
valid, wormholes most assuredly do not exist. If
they did it would probably send shivers up the
science fiction community"s spine. In the book,
Relatively Speaking, the Author, Eric Chaisson
says, "The world of science is littered with
mathematically elegant theories that apparently
have no basis in reality" (182). Although black
holes have not been conclusively proven to exist,
there is strong evidence, in the observable
universe, that they do. Black holes are very
important to the world of cosmology. They allow
for the study of common particles under very
uncommon environmental variables. Scientists
have vastly increased their knowledge of the
universe and the properties of matter through the
study of a black holes effects on light, time and the
fabric of the space. Works Cited Bunn, Ted
"Black Holes FAQ." NSF Science and
Technology Center (September 1995): Online.
Internet.
http://physics7.berkeley.edu/Bhfaq.HTML
Chaisson, Eric. Relatively Speaking: Relativity,
Black Holes, and the Fate of the Universe. New
York: W.W. Norton & Company, 1988.
Hawking, Stephen. A Brief History of Time: From
the Big Bang to Black Holes. New York: Bantam
Books, 1988. Manthe 5