Picture the Milky Way is modeled with high resolution (image resize, original file size 4722x4722) A team of astronomers at the University of Zurich (UZH) and the Federal Institute of Technology Switzerland (ETH), together with the international community has announced they had found evidence that there exists a large amount of dark matter near the Sun. This result is entirely consistent with the hypothesis that the Milky Way - the galaxy in which we live is surrounded by a massive halo of invisible matter. However, this is the first time scientists are testing it by computer based on actual data and the simulation accuracy. As usual, Tinhte will give you some basic knowledge to be able to understand this interesting question. First we imagine two bodies problem gravitational interaction with one another, such as Earth and the Sun, for example. You know that the attraction between them will obey the laws of Newtonian gravity or, more accurately if using Einstein's theory of relativity, so the Earth moves around the sun in circular or elliptical orbit. If only two things, the assumptions are correct, but completely realistic way. A third object will appear to orbit the Earth was slightly command, this phenomenon called the motion by the gravitational perturbations. Because there are so many governing bodies like the planets in our solar system, other small celestial bodies ... So the path of the Earth will make a similar ellipse. However it is possible to calculate if we know the object is what impact (if ignore objects with masses too small or too far away). If the results are given is not consistent with the fact that there must be at least one object has more mass effect on the Earth that we do not know. Based on that basis, scientists will search for new planets or objects. But when the problem has thousands of objects, the problem becomes more complicated, it requires the aid of computers and numerical methods to calculate and simulate from actual data. Note that Tinhte give you this example to understand the problems associated with the other problem, but the fact that people have accurate calculation of the Earth the way I got you. We now go back to the issues related to research at the UZH and ETH. Dark matter is a concept launched by a Swiss astronomer Fritz Zwichky professor in 1930. When observing the motion of groups of galaxies, he found that among us there must be a form of matter that keeps the galaxies do not move apart. At the same time Dutch researcher Jan Oort found near the density of matter near the Sun twice as large because the density of stars and dust and gas contributors. So must exist other mysterious objects contribute to the new volume appears. In both cases above, we have conducted thorough observations still do not see a particular object. Clearly, that form of matter predicted Fritz and Jan is not ordinary matter, they are called dark matter. Here, Tinhte continue to accompany you to better understand the mysteries of the universe. As above, dark matter can not be charged because if we found them by the electromagnetic radiation emitted. We also can not participate in strong interactions because such force that they influence material usually will be greater than gravity. Thus dark matter only two types of interaction is attractive and weak interactions. Therefore they interact very weakly with normal matter, which is one of the reasons that people measure and difficult to detect. The effects often occur when large amounts of dark matter concentration is the phenomenon of gravitational lensing. This phenomenon occurs when the transmission of light is bent by gravity before they go to the telescopes of man. That also happens to black holes, black holes but not the dark matter because we can identify them by other phenomena. Tinhte specific cause will have the opportunity to introduce to you in a later article. The refer you to an introduction of Tinhte to better understand the interactions in the wild here If dark matter is the fundamental particles, it is really a great discovery For many decades scientists have developed the theory of dark matter and the formation of them to explain the results when measuring the gas and galaxies with the telescope. However, the modern means of observations and new techniques for calculating the amount of dark matter is more than 3 to 6 times higher than the prediction based on old data. Until last year, scientists once again became confused as the only experimental amounts of dark matter less than expected. At that time, the community of physicists believe the analysis and observation is not enough precision necessary to be able to provide reliable results to a premise for the theoretical model. Check out the new method based on simulated Milky Way In order to overcome common problems in previous research, the team of scientists led by researchers from ETH UHZ and has developed a measuring method of calculating the new volume. To be sure, they check the accuracy of this method through simulation process Milky computer before applying it to real data. Since then they give some interesting conclusions. The results obtained demonstrate measurement techniques and data processing is applied in the past 20 years has led to serious deviations. That's led to the mass estimate of dark matter less real. After putting the data on positions and velocities of thousands of dwarf stars near our solar system as input parameters in the calculation, the Swiss scientists have made new findings on the matter density in the this area. Evidence of dark matter near the Sun Professor Silvia Garbari-led research team says that their calculations were done to prove the existence of dark matter near the sun with an accuracy of up to 90%. The remaining 10% is due to the statistical error and this number will decrease when more accurate data in the future. Silvia explained, "This may be the first evidence of the existence of disk dark matter in the Milky Way as predicted by theory and numerical simulation of the formation of galaxies, or at least have a dark matter exists and it is compressed to measure the mass density is very high. Initially it was believed that dark matter particles are neutrinos because it satisfies two criteria are only weakly interacting and participating attractions. However in 1960 the experimental evidence has rejected this hypothesis. Today, many physicists believe that dark matter is made up of elementary particles outside the Standard Model. The particles are characterized by only weak interaction and gravitational interaction with ordinary matter. To detect such grains should have the exact experimental set deep in the ground soil. Professor George Lake, members of the team, added, "if dark matter really is the fundamental particles, billions of particles passes through your body every second that you can not feel. Physicists experimentally measured only hope a few seeds every year in the experiment known as Xeon or CDMS. Therefore, understanding the nature and distribution of dark matter is an important key to the mysterious curtain about the fundamental particles created them. Source: University of Zurich (UZH) ...
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