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Black Holes

Subject: Physics
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InledningVad is really a black hole? Is it so important? In the media there has been talk very much about black holes since man discovered them. Black holes are arguably one of the most fascinating and interesting phenomenon we know exist. But yet we know so little about them.
How can we be sure that they are? They're like I said black, you can not see them.
Can we take advantage of them in some way?

The term black hole was coined in 1969 by the American scientist John Wheeler. It was not a new idea, the idea goes back at least two centuries, to a time when there were two theories of light. The one, which Newton favored, was that light consisted of particles and the other that it consisted of waves. Today we know that both matches thanks to quantum mechanics, light can be seen both as a wave and as a particle. If light consisted of waves did not know how, or if, it was affected by gravity. But if it consisted of particles would be affected as much by gravity as any other matter. It was believed that light traveled infinitely fast and that's why the light was not affected, but this was not as a scientist named Roemer discovered that light traveled at a finite speed.
For those who believed in the wave theory was not clear that the light would be affected by gravity at all. In fact, Newton's theory of gravity can not be used to light because light always have the same speed. That light affected by gravity and how was not until Einstein presented his theory of relativity.
A star's life cycle

To understand black holes, we must first understand a star's life cycle. A star is formed when a large quantity of gas (mostly hydrogen) collapses, thanks to gravity. The gas temperature increases as they come closer and closer together and there will be more collisions. Eventually the temperature becomes so great that the hydrogen atoms begin to merge with each other and form helium atoms. It is at this stage that our Sun is located. In the end, take the fuel out and the star begins to contract. About The star then weigh less than 1.4 times the mass of our sun, we will get a white dwarf. They become stable bodies thanks to someone called exclusion principle. This is a force that worked against gravity of these stars and make them stable. Exclusion Principle is a repulsive force between the electrons in the atoms.
For stars that have masses larger than 1.4 solar masses, there are two options. One is that the star becomes stable due to the exclusion principle between neutrons and protons in the atomic nuclei. These are called neutron stars. The other option is if gravity of the star is so high that not even the exclusion principle is able to keep up the star. It thus formed is a black hole.
Black Holes

A black hole can with simplicity described as a celestial body that has so much gravity that its escape velocity is higher than the speed of light. A black hole has no radius. Gravity has compress all matter to no volume at all. It is a singularity of infinite mass density. The black hole has a blasphemy horizon. This could be considered as a radius, but there is actually a limit on the black hole. Event Horizon forecloses any communication between the black hole and beyond. Everything that comes inside the event horizon swallowed by the black hole, inside the event horizon, there is no turning back. The distance between the black hole and event horizon depends on the hole's gravity.
As we know, nothing can travel faster than light. Therefore never disappear no matter from the body. Matter that comes inside the black hole's event horizon is pulled down to the singularity of the black hole's center, and the black hole grows. Thus, black holes grow but not decrease.
Gravitational Waves and Black Hole form

Einstein's theory of general relativity predicts that really heavy objects that move will send "ripples" in space-time, traveling at the speed of light. These waves are similar to light waves but are much harder to detect. You can view them by the shifts of different particles that are freely movable. Man holds today on building detectors in the U.S., Europe and Japan to measure this. Like light waves as they bring energy from its source. One can then expect that the source which would eventually come to rest.
The Earth's motion in its orbit around the sun also gives rise to gravitational waves. The energy losses from these will alter the Earth's orbit around the sun so that the Earth will gradually closer to it. But since the energy losses are so small (you would run a heat stove on losses), this will not mean anything to us because it would take about a thousand million million million one million years for the Earth to go into the sun. Ground Task change is too small to be able to be measured but has seen similar phenomena in the star system
PSR 1913 +16 (this is a pulsar). The system consists of two neutron stars orbiting each other and the energy loss due to gravitational waves makes them wander in a spiral towards each other and they will eventually collide.
During the gravitational collapse when a star forms a black hole, the movement is much higher and the radiation rate of gravitational waves is much higher. It is therefore quite fast for it to come to a resting state. This is the star's last stage before it becomes a black hole.
1967 showed researcher Werner Israel to non-rotating black hole structure was very simple. He argued that the black hole's structure is not at all meant to the characteristics of its original star had (except when the mass of course). They are perfectly spherical, and its size is made up only of its mass. Two black holes with equal masses are therefore identical. Many felt that this thesis is not working at all because the black hole then it must have formed from a perfectly spherical star (which is not). There was, however, a different interpretation. When the black hole went through its final stage, it became the perfect spherical shape the outcome of the many gravity waves. When it came to rest the object would be perfectly spherical. According to this view, all non-rotating stars, in any form, quit as a perfect spherical body and its size would depend only on its mass. The theory was limited to celestial bodies that are not rotated but 1963 did the researcher Roy Kerr, a collection of additional equations to Einstein's general relativity, which described rotating black holes. If the rotation was zero so would the black hole to be perfectly spherical. But if it rotated so it would "bulge" at the poles. 1970 corroborated this theory of evidence from David Robinson. All black holes will eventually end up a vilostånd where they can rotate. He proved also to its shape and size was due solely to its mass and its rotation rate and not on the properties that its star had. This result became known as the maxim: "A black hole has no hair."
How to Detect Black Holes

Since black holes are have so much gravity that light does not come from them, we can not see them. However, there are other ways to detect black holes.
The light from the stars in the vicinity of black holes to bend very much about them because they have so much gravity. If the light comes inside the event horizon, we do not, but if it only comes close to the border, it will be bent sharply. Many also argue that if the light comes in at a specific angle in the event horizon, it will "go" around the black hole alongside the event horizon.
The most common and probably the easiest way to detect black holes is to look at their nearby neighbors. One can in some places see how big stars revolve around an "invisible" point. It does not mean that there are black holes, it could have been a very faint star. But it could mean that there is a black hole. Such a system is called Cygnus X-1. In this case, with the aid of calculations on the visible celestial body's orbit have been able to figure out the "unseen" minimal mass, which in this case was 6 solar masses. Thus exclude that it is a black dwarf. Massa is also too large to object must be a neutron star.
We assume now that there are black holes in our own galaxy, the Milky Way, since the mass of the stars we see in our galaxy is not enough to give the Galaxy the rotation as it has. We also believe that there are black holes with a mass of about a hundred million solar masses. For example, observations with the Hubble Space Telescope of the galaxy M87 revealed that there is a disc-shaped galaxy that rotates around a central object that can not be anything other than a black hole. Matter falling into a place like this super black hole, go down the hole in a spiral (like when you let the water out of the tub) and then get the black hole rotate in the same hole. This produces a magnetic field similar to Earth's. Near the black hole, it will create high-energy matter of the incident particles. The magnetic field is so strong that it 'throws' this matter straight out of the disk-shaped galaxy. This has been observed in many galaxies and quasars.
One way to observe black holes is to measure gravitational waves, this is not quite possible today, but you think it will be so in the near future.
Black holes thumbnails

One can imagine the possibility that there is much less black holes, which have less mass than even our own sun. Such holes can not be formed by a gravitational kolapps because mass is under Chandrasekhar limit. Miniature black holes may be formed only on the matter is compressed by external pressure. According to John Wheeler would form a miniature black hole if you took all the heavy hydrogen in Earth's oceans and made one big hydrogen bomb it. It is believed that it has formed many of these smaller black holes in the universe's early stage. Apparently even the big bang would have enough power to compress the mass so that it formed miniature black holes. Many scientists believe that there are more thumbnails of black holes than the "normal" black holes.
The use of black holes

If, in the future would be able to "catch" a miniature of a black hole by its gravity would be able to earn a lot of it. Since all matter moving down towards a black hole emits energy. Energy problems would forever been resolved.
Another scenario could be that we "bump" into a black hole in the orbital path around the Earth (a very small miniature black holes), then we will send a constant stream of hydrogen that just touches on its event horizon. The hydrogen will then heated to fusion, thanks to the tidal effect and, on the other hand, helium. This then is the easiest and safest possible nuclear fusion reactor, and the energy can be stored and sent down to Earth.

Time travel has long fascinated humans. In the 1950s there were many scientists who did research in just that. Something that has intrigued us is whether it is possible to travel to remote locations quickly. According to Einstein's theories, nothing can fördas faster than light. One consolation however, may be the so-called twin paradox, which means that if you travel at the speed of light, time stands still. Relativity theory suggests, however, that if you travel faster than light then travels back in time. The problem then is that the closer to the speed of light you get, the more power you will be influenced by, and you will never give up the speed of light. That compares with sharing a century by two. You get closer and closer to zero, but you will never reach it.
This seems to rule out both fast space travel and travel back in time. However, there is another possibility. If one can deform spacetime so as to create a shortcut between two points in space, a wormhole. In this way, one could travel faster between two points in space. But it would also allow tidresor. Wormholes are not something that science fiction writers have come up, but it was Einstein and Nathan Rosen in 1935 wrote an essay about something they called "bridges", which today is known as the wormhole. But they also said that anyone who traveled through the hole would chute right into a singularity, a black hole. It would also not be able to keep the wormhole open long enough.

That black holes exist, most agree. Many claim in and of itself is still that black holes do not exist and that it is uncertain because most of what is about black holes is not based on observation but rather on mathematical calculations. The research on black holes is probably the first in history that has gone on in this way with the right calculations prior observations. I think that the black holes will be what is being researched into in the future.
Many of those who believe that the universe was created from the big bang also believe that it will end in a big crunch, one big contraction. Much of the theories about how precisely the black hole can not destroy, and how all matter in the universe as adhering to various black holes and how they eventually collide with each other until there is only one big black hole with all the mass in the universe. But we live in a time where there constantly added things to it that is widely accepted and it constantly falls off things that were widely accepted. Now it is discussed whether the universe is flat. And perhaps this can help to clear up the picture we have of the universe. I personally do not because black holes are "immortal" (or maybe I do not want to believe it?!) That the universe ends in a big crunch, I think not on. Man is an avid creature, we are always trying to understand everything. We get "clues" from all other sciences, but can not foresee it, we must unite science!
To speculate on matters fate of the universe is more than we can handle, we need to take a little at a time to see the big picture. The answers are there, we just have to ask the right questions.

By: Isaac Fahlin

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