Albert Einstein's equation E = MC ^ 2 is perhaps the best known equation of the century. On earth, this equation is used to measure the level of matter and mass in a room, but when applied in a space anomaly appears. When we use Einstein's equations to determine how much matter the universe should have, we would realize that there are only 4 percent of the exhibit material truth, in terms of mass and can be perceived by the human senses. Where are the rest?
Many people believe that the remaining approximately 96 percent in the form of Dark Matter. Researchers still have not been able to show evidence of dark matter whether it really exists, that in fact we can not see, touch, even light and radio signals can penetrate. All of these are causes of dark matter is very difficult to be detected and verified.
Some scientists think dark matter is a very large objects such as black holes can not be seen floating around the galaxy. Other scientists believe that dark matter is the subatomic particles that rarely interact with ordinary matter, seen from the point of view that dark matter can not be touched even seen because light can easily penetrate without the slightest flaw.
Research on Dark MatterIn 1933, Swiss astronomer Fritz Zwicky of CalTech decided to study a small group of seven galaxies in the Coma Cluster. The goal is to calculate the total mass of the cluster is to study the speed (or rather velocity dispersion) of the seven galaxies. He calculated the mass of the 'dynamic mass', then compare it with the 'luminous mass', which is calculated from the mass amount of light emitted by the cluster (by making the assumption of probability distribution of stellar populations in galaxies). Velocity dispersion (or in other words, how the speed of 7 galaxies differ from one another) is directly related to the cluster's mass. In fact, a star cluster can be compared with the gas. If the hot gas and glowing, the spread of high-speed particles. In extreme cases, the particles that have enough speed to leave the gas (vapor). When the gas is cold and heavy, weak velocity dispersion. Zwicky was surprised that the speed was observed in the Coma Cluster is very high. Dynamic mass has a mass 400 times greater than the luminous mass! Zwicky announced observations of his colleagues, but they were not interested.
Of the many theories, there are two main theories opposing continue to try to explain the nature of dark matter, the hot dark matter and cold dark matter. These theories rely on the mass and speed of the particles making up dark matter. In the hot dark matter theory, the particles have a velocity approaching the speed of light, while the cold dark matter bigger so more slowly.
Velocity of these particles is very important for the Big Bang model of cosmology and structure formation order of the universe. If the composition of the main universe is made of hot dark matter, a very high speed of the particles initially will prevent the formation of small structures first, ranging from galaxy supercluster galaxies and then clusters of galaxies then later in smaller structures.
The development of the universe with this method is commonly called the BOTTOM UP, which is the largest structure was first formed then form smaller structures. On the other hand, if the cold dark matter is the main component of the universe, the particles will be scattered at smaller distances and thus would remove density fluctuations in the volume of a smaller space. These materials will be assembled to form galaxies (ranging from clouds of gas and smaller structures), which then form a cluster, and supercluster. Scenarios such as the formation of the universe is called the BOTTOM UP, where the structure of the first terkecillah formed which then come together to form larger structures.
These theories held by Yakov Borisovitch Zeldovitch for hot dark matter, and James Peebles for cold dark matter.
Some astrophysicists added to provide String theory, dark matter theory was put to the sixth dimension, because it is dark matter can not be accessed from our dimension that are on the order of four (three spatial dimensions, one time dimension), even the electromagnetic and nuclear power will not be able to reach and the influence of dark matter bounded by the walls of different dimensions.
There is a theory that provides an explanation of the Axion Dark Matter. Axion is a remarkable material that has the strength of electron light 1μeV, stable and rarely interact with matter.
Black hole?It has a super large size and are rarely seen making a black hole as the right candidate. Some of them even hit 10 thousand solar masses. Keeping track of a black hole is very difficult because it is absorbing anything including light flashed. However, unfortunately it took nearly a million black holes other than the present to fill the void of matter
Neutrino particle?Neutrino is a particle that was first introduced in 1930 by Wolfgang Pauli, which was detected in 1956 by Frederick Reines and Clyde Cowan. These particles are not sensitive to the electromagnetic force and the strong nuclear force, the neutrino does not interact much with other particles.
Neutrino masses are very small, almost zero. In addition, neutrinos are the most abundant particles in the universe after photons. However, experiments Super-Kamiokande and SNO (Sudbury Neutrino Observatory) shows the neutrino mass even small enough to assume this will be a particle of dark matter. Neutrinos can represent at least 18% of the mass of the universe. Not 96%
MACHO's?Massive Compact Halo Objects is a large dark object like a brown dwarf star, white dwarfs, neutron stars and black holes
WIMP's?(Weakly interacting massive particles) is a range of non-baryonic subatomic particles (rather than ordinary matter) are believed to be formed by the Big Bang. Many theories predict the existence of WIMP particle such as neutralinos, axions and neutrinos great, but not really detected. if WIMP really exists, then it is likely composition is WIMP Dark Matter
We will never be able to uncover all the hidden secrets of nature, humans can only grope towards the truth.