The Search For Black Holes Both As

A Concept And An Understanding Essay, Research Paper

The Search for Black Holes: Both As A Concept And An Understanding

For ages people have been determined to explicate on everything. Our

search for explanation rests only when there is a lack of questions. Our skies

hold infinite quandaries, so the quest for answers will, as a result, also be

infinite. Since its inception, Astronomy as a science speculated heavily upon

discovery, and only came to concrete conclusions later with closer inspection.

Aspects of the skies which at one time seemed like reasonable explanations are

now laughed at as egotistical ventures. Time has shown that as better

instrumentation was developed, more accurate understanding was attained. Now it

seems, as we advance on scientific frontiers, the new quest of the heavens is to

find and explain the phenomenom known as a black hole.

The goal of this paper is to explain how the concept of a black hole

came about, and give some insight on how black holes are formed and might be

tracked down in our more technologically advanced future. Gaining an

understanding of a black hole allows for a greater understanding of the concept

of spacetime and maybe give us a grasp of both science fiction and science fact.

Hopefully, all the clarification will come by the close of this essay.

A black hole is probably one of the most misunderstood ideas among

people outside of the astronomical and physical communities. Before an

understanding of how it is formed can take place, a bit of an introduction to

stars is necessary. This will shed light (no pun intended) on the black hole

philosophy.

A star is an enormous fire ball, fueled by a nuclear reaction at its

core which produces massive amounts of heat and pressure. It is formed when two

or more enormous gaseous clouds come together which forms the core, and as an

aftereffect the conversion, due to that impact, of huge amounts of energy from

the two clouds. The clouds come together with a great enough force, that a

nuclear reaction ensues. This type of energy is created by fusion wherein the

atoms are forced together to form a new one. In turn, heat in excess of

millions of degrees farenheit are produced.

This activity goes on for eons until the point at which the nuclear fuel

is exhausted. Here is where things get interesting. For the entire life of the

star, the nuclear reaction at its core produced an enormous outward force.

Interestingly enough, an exactly equal force, namely gravity, was pushing inward

toward the center. The equilibrium of the two forces allowed the star to

maintain its shape and not break away nor collapse.

Eventually, the fuel for the star runs out, and it this point, the

outward force is overpowered by the gravitational force, and the object caves in

on itself. This is a gigantic implosion. Depending on the original and final

mass of the star, several things might occur. A usual result of such an

implosion is a star known as a white dwarf. This star has been pressed together

to form a much more massive object. It is said that a teaspoon of matter off a

white dwarf would weigh 2-4 tons. Upon the first discovery of a white dwarf, a

debate arose as to how far a star can collapse. And in the 1920?s two leading

astrophysicists, Subrahmanyan Chandrasekgar and Sir Arthur Eddington came up

with different conclusions. Chandrasekhar looked at the relations of mass to

radius of the star, and concluded an upper limit beyond which collapse would

result in something called a neutron star. This limit of 1.4 solar masses was

an accurate measurement and in 1983, the Nobel committee recognized his work and

awarded him their prize in Physics. The white dwarf is massive, but not as

massive as the next order of imploded star known as a neutron star. Often as

the nuclear fuel is burned out, the star will begin to shed its matter in an

explosion called a supernovae. When this occurs the star loses an enormous

amount of mass, but that which is left behind, if greater than 1.4 solar masses,

is a densely packed ball of neutrons. This star is so much more massive that a

teaspoon of it?s matter would weigh somewhere in the area of 5 million tons in

earth?s gravity. The magnitude of such a dense body is unimaginable. But even

a neutron star isn?t the extreme when it comes to a star?s collapse. That

brings us to the focus of this paper. It is felt, that when a star is massive

enough, any where in the area of or larger than 3-3.5 solar masses, the collapse

would cause something of a much greater mass. In fact, the mass of this new

object is speculated to be infinite. Such an entity is what we call a black

hole. After a black hole is created, the gravitational force continues to pull

in space debris and all other types of matter in. This continuous addition

makes the hole stronger and more powerful and obviously more massive. The

simplest three dimensional geometry for a black hole is a sphere. This type of

black hole is called a Schwarzschild black hole. Kurt Schwarzschild was a

German astrophysicist who figured out the critical radius for a given mass which

would become a black hole. This calculation showed that at a specific point

matter would collapse to an infinitely dense state. This is known as

singularity. Here too, the pull of gravity is infinitely strong, and space and

time can no longer be thought of in conventional ways. At singularity, the laws

defined by Newton and Einstein no longer hold true, and a “myterious” world of

quantum gravity exists. In the Schwarzschild black hole, the event horizon, or

skin of the black hole, is the boundary beyond which nothing could escape the

gravitational pull.

Most black holes would tend to be in a consistent spinning motion, because of

the original spin of the star. This motion absorbs various matter and spins it

within the ring that is formed around the black hole. This ring is the

singularity. The matter keeps within the Event Horizon until it has spun into

the center where it is concentrated within the core adding to the mass. Such

spinning black holes are known as Kerr Black Holes. Roy P. Kerr, an Australian

mathematician happened upon the solution to the Einstein equations for black

holes with angular momentums. This black hole is very similar to the previous

one. There are, however, some differences which make it more viable for real,

existing ones. The singularity in the this hole is more time-like, while the

other is more space-like. With this subtle difference, objects would be able to

enter the black whole from regions away from the equator of the event horizon

and not be destroyed.

The reason it is called a black hole is because any light inside of the

singularity would be pulled back by the infinite gravity so that none of it

could escape. As a result anything passing beyond the event horizon would

dissappear from sight forever, thus making the black hole impossible for humans

to see without using technologicalyl advanced instruments for measuring such

things like radiation. The second part of the name referring to the “hole” is

due to the fact that the actual hole, is where everything is absorbed and where

the center core presides. This core is the main part of the black hole where

the mass is concentrated and appears purely black on all readings even through

the use of radiation detection devices.

The first scientists to really take an in depth look at black holes and

the collapsing of stars, were a professor, Robert Oppenheimer and his student

Hartland Snyder, in the early nineteen hundreds. They concluded on the basis of

Einstein’s theory of relativity that if the speed of light was the utmost speed

over any massive object, then nothing could escape a black hole once in it’s

clutches. It should be noted, all of this information is speculation. In theory,

and on Super computers, these things do exist, but as scientists must admit,

they?ve never found one. So the question arises, how can we see black holes?

Well, there are several approaches to this question. Obviously, as realized

from a previous paragraph, by seeing, it isn?t necessarily meant to be a visual

representation. So we?re left with two approaches. The first deals with X-ray

detection. In this precision measuring system, scientists would look for areas

that would create enormous shifts in energy levels. Such shifts would result

from gases that are sucked into the black hole. The enormous jolt in

gravitation would heat the gases by millions of degrees. Such a rise could be

evidence of a black hole. The other means of detection lies in another theory

altogether. The concept of gravitational waves could point to black holes, and

researchers are developing ways to read them. Gravitational Waves are predicted

by Einstein?s General Theory of Relativity. They are perturbations in the

curvature of spacetime. Sir Arthur Eddington was a strong supporter of Einstein,

but was skeptical of gravity waves and is reported to have said, “Graviatational

waves propagate at the speed of thought.” But what they are is important to a

theory. Gravitational waves are enormous ripples eminating from the core of the

black hole and other large masses and are said to travel at the speed of light,

but not through spacetime, but rather as the backbone of spacetime itself.

These ripples pass straight through matter, and their strength weakens as it

gets farther from the source. The ripples would be similar to a stone dropped

in water, with larger ones toward the center and fainter ones along the outer

circumference. The only problem is that these ripples are so minute that

detecting them would require instrumentation way beyond our present capabilities.

Because they?re unaffected by matter, they carry a pure signal, not like X-rays

which are diffused and distorted. In simulations the black hole creates a

unique frequency known as it natural mode of vibrations. This fingerprint will

undoubtedly point to a black hole, if it?s ever seen.

Just recently a major discovery was found with the help of The Hubble Space

Telescope. This telescope has just recently found what many astronomers believe

to be a black hole, after being focused on a star orbiting an empty space.

Several picture were sent back to Earth from the telescope showing many computer

enhanced pictures of various radiation fluctuations and other diverse types of

readings that could be read from the area in which the black hole is suspected

to be in.

Because a black hole floats wherever the star collapsed, the truth is, it can

vastly effect the surrounding area, which might have other stars in it. It

could also absorb a star and wipe it out of existance. When a black hole

absorbs a star, the star is first pulled into the Ergosphere, this is the area

between the event horizon and singularity, which sweeps all the matter into the

event horizon, named for it’s flat horizontal appearance and critical properties

where all transitions take place. The black hole doesn?t just pull the star in

like a vaccuum, rather it creates what is known as an accretion disk which is a

vortex like phenomenom where the star?s material appears to go down the drain of

the black hole. When the star is passed on into the event horizon the light

that the star ordinarily gives off builds inside the ergosphere of the black

hole but doesn?t escape. At this exact point in time, high amounts of radiation

are given off, and with the proper equipment, this radiation can be detected and

seen as an image of emptiness or as preferred, a black hole. Through this

technique astronomers now believe that they have found a black hole known as

Cygnus X1. This supposed black hole has a huge star orbiting around it,

therefore we assume there must be a black hole that it is in orbit with.

Science Fiction has used the black hole to come up with several movies and

fantastical events related to the massive beast. Tales of time travel and of

parallel universes lie beyond the hole. Passing the event horizon could send

you on that fantastical trip. Some think there would be enough gravitational

force to possible warp you to an end of the universe or possibly to a completely

different one. The theories about what could lie beyond a black hole are

endless. The real quest is to first find one. So the question remains, do they

exist?

Black holes exist, unfortunately for the scientific community, their life is

restricted to formulas and super computers. But, and there is a but, the

scientific community is relentless in their quest to build a better means of

tracking. Already the advances of hyper-sensitive equipment is showing some

good signs, and the accuracy will only get better.