Although no one knows what it is, there is a reason for astronomers to use the concept of dark matter as bolo. In fact, dark matter is used to explain facts that cannot appear otherwise.

For example, due to its rapid rotation speed, some galaxies would be dispersed according to current theories. Somehow, its mass is not enough to withstand the material that rotates at that speed. The idea of dark matter serves to explain these facts: there is a matter that we do not see, therefore dark, that provides these galaxies with a sufficient mass not to disperse them.

Other galaxies, called nana galaxies, although they do not have a rapid rotation, have little visible mass. This mass could not generate enough gravitational force and the galaxy would be dispersed. But it can be assumed that there is matter that is not seen holding the cloud. In the case of dwarf galaxies, the missing matter should be 30 times the Sun.

In short, to explain the effects of the gravitational forces present in the universe, in general, lack matter. That matter lacking in the universe is dark matter, which is missing for everything to go well.

Looking for dark matter

To explain the gravitational forces that occur in the universe, it is necessary, therefore, to go in search of dark matter. And, if there is matter of this type, you will first have to know where it is.

In February last year they found in the set of stars of Virgo a galaxy formed by dark matters. At first they found the hydrogen cloud and supposed it could be a dwarf galaxy, so they did not see it. However, after analyzing how hydrogen was moving, astronomers realized that it should have a mass greater than it seemed. But then the cloud would have enough mass to turn on the stars and could be seen with an amateur telescope where no stars appeared. However, if it is supposed to be a galaxy made up of dark matter, the gravitational fields around the cloud can appear smoothly.

Studies of this type indicate that dark galaxies are more abundant than conventional galaxies. Another hypothesis is that dark matter surrounds conventional matter thanks to its gravitational influence, so it is of vital importance when creating stars and other stars.

Fast stars to analyze dark matter

Also in February last year, astronomers found a star at 700 km per second. Although stars cross the space at high speed, this speed is huge for a star. It is twice the speed that a milky track star needs to leave the orbit, which is what will happen to the Rejected Star, which has given it that name. It goes so fast that it goes directly from our galaxy out. The Excluded Star is not the only one to abandon the Milky Way, astronomers have catalogued about 10,000 stars of this type, but the Discarded Star has the speed record.

The extraordinary speed of the Marginalized Star is an advantage for astronomers by the influence of their gravitational interactions with other stars. When passing near a star it will deviate. But it will also suffer inexplicable deviations, which now slows down and now accelerates. In this way, one can analyze the influence of dark matter, which is not seen.

The lens of gravity also allows us to analyze the dark matter

In the wake of dark matter there is another cosmic effect that can be useful, the effect of the lens of gravity. The gravitational force that generates the mass of a galaxy returns the light that passes to its side, that is, gravity makes the effect of the lens. The estimate of the torsion that suffers from light allows to know the influence of the mass of dark matter on torsion and, therefore, to calculate the same mass of dark matter. It is believed that the mass of dark matter is 80% of the mass of the universe, while in the case of the Milky Way this proportion is 90%.

The extension of the lens of gravity is of the order of 1%, being adequate the quasars to study this cosmic increase. In fact, the quasars are luminous and, as they are very far away, their light suffers the lens of gravity of many cosmic objects before reaching the Earth.

Properties of dark matter

So far it has been seen that in the universe there is something called dark matter and whose existence is demonstrated by the interactions of gravity. And if it exists it will have properties. But what are they?

Dark matter seems too fleeting to obtain direct information about it. No electrical charges, magnetism, or interactions with light or radiation have been found. Considering these properties -- these disproperties -- it seems difficult for astronomers to learn more about dark matter. Not much less.

To justify the existence of dark matter, astronomers have used dwarf galaxies with which it seems logical to be able to extract more information. To begin with, they have deduced that the velocity of dark matter of nana galaxies is 9 km per second. From this speed the cloud that forms the dwarf galaxy would disperse, while below that speed the cloud would be compacted. With this information, and by pulling the string of physical equations, it can be concluded that the temperature of the dark matter is 10,000 °C.

This seems like a relatively high temperature for a matter that does not generate any type of light. According to the first hypotheses, dark matter necessarily needed cold. But the hypothesis of cold dark matter posed many problems. Among other things, small galaxies should be orbiting larger galaxies and this type of cosmic structures has not yet been found anywhere. The hypothesis of hot dark matter, on the other hand, does not present this type of deficiencies.

Dark energy dark energy

Once the existence of dark matter is justified, and after mentioning some of its properties, we can analyze the hypotheses of origin of dark matter. For this, it is essential to enter the field of quantum physics and mention black holes. One of the hypotheses is that black holes are stars of dark energy. The idea that the universe is expanding is something accepted among astronomers and the hypothesis is that dark energy is responsible for this expansion.

According to the hypothesis, the black hole exerts enormous gravity on the outer matter. However, within the black hole, the matter is transformed into antimatería and is again expelled to the outside. Materials and antimaterías are destroyed and released high energy radiation. That would be the source of the radiation that is generated in the centers of galaxies.

In addition to black holes, the hypothesis says that there should be other dark energy stars, called fundamental. The latter would not occur as traditional black holes -- black holes are a consequence of the collapse of the stars -- but through space-time fluctuations. Somehow, just as in a cloud of water vapour the drops of water are condensed, in quantum space-time stars of dark energy are also formed. These stars would generate the severity of the usual ones, but they would be invisible. That is, it would be formed by dark matter.

Intention to create dark matter in laboratory

It seems that although its influence on space can be seen, it will be very difficult to find the dark matter itself through a telescope. And as it will be difficult to find it in space, they are conducting other experiments to find dark matter. For example, at the University of Zurich they have performed simulations through a supercomputer and have concluded that in the Milky Way there are 10 15 halos of dark matter. This means that the Earth crosses one of these halos every 10,000 years.

But, in addition to performing simulations, scientists are also thinking about creating dark matter in the laboratory. To do this, they intend to create in the laboratory a subatomic particle called neutralin, which is one of the candidates for the generation of dark matter. Neutralin has never been detected, but the theory of supersymmetry suggests its existence and determines its mass and how it can occur.

Neutralin is the antiparticle of itself. This means that two neutralins are destroyed when colliding. In this shock, gamma rays are produced. However, this type of explosions are rare. The LHC particle accelerator, which is being built at the CERN laboratory in Geneva, is expected to serve the generation of neutralines and other supersymmetric particles, and to be available in 2007.