But what now is this dark matter for anything? night lights This is discussed Bjorn Samset night li

After getting some help from Albert Einstein and a large telescope in Hawaii, to a group of astronomers this week will present an impressive map. The map shows how dark matter is distributed throughout night lights the universe. Not bad, considering that dark matter is invisible.
Because if you think there is a lot of fascinating watching around the world, you should know that there is an invisible reality out there that are even bigger. Everything we see around us - jams, Malagasy sneak cats, planets night lights and stars - is made of ordinary matter. Nevertheless constitute the regular matter only about 5% of the content of the universe. The main ingredient - a strange screw we call dark energy - accounts for about 70% of the total content.
The last 25 percent think we consist of something called dark matter. This is a kind of invisible, intangible particles night lights that no human has ever seen. However, we are fairly certain that dark matter exists. So make sure that it is now made a map of where it is located.
But what now is this dark matter for anything? night lights This is discussed Bjorn Samset night lights and I in a movie at the Colloquium just before Christmas. In short, dark matter the type of particles that have mass but no electrical charge. The dark matter particles have mass means they feel gravity forces: Dark matter night lights affects and is affected night lights - via gravitational forces - of all other particles in the universe. The particles have electric charge means that they are both invisible and intangible.
When the sun or a light bulb lights up, it is because electrically charged particles - electrons typically - gets shook. When you see a moose in the woods, the electrically charged particles in the fur on the moose that reflect light. When light from the moose perceived by eye, it is because the retina is electrically charged particles that can absorb light. Particles with electric charge, such as dark matter, cares simply about light. A better name might therefore have been invisible night lights matter.
But we can imagine that there are invisible moose made of dark matter? No, electric charges leads not only to the moose is visible, but also that it hangs together. If we could magically turned off all electrical night lights charges, would you, me and Bullfinch been converted into an unstructured soup of particles without resistance would fall through the ground and down to earth. Dark matter collides not with other matter, do not feel pressure forces and can therefore not create dense structures.
This lack the ability to form dense structures night lights means that you will not find moose, planets, stars and small galaxies made entirely of dark matter. Instead, dark matter form large, thin veil around galaxies and galaxy clusters (clumps of galaxies). For example, we estimate that the visible part of the Milky Way swim in a diffuse, spherical haze of dark matter extending night lights out to a radius that is several times larger than the visible part of the galaxy.
And how can we be so sure that dark matter exists and that it is not just a figment creative hatched in desperate astrophysicist night lights heads? Reasons to believe in dark matter are numerous and very different. Some indications include how objects in the universe moves. For example, it turns out that the speed of the outer stars of spinning galaxies are so large that they would be thrown away from the galaxy carousel if there was a good bit of extra matter in the galaxy. Dark matter manisfisterer also in microwave radiation night lights from the universe's infancy and the statistical distribution of galaxies in the sky. In addition, we can "see" dark matter indirectly through so-called gravitational lensing.
An example of strong gravitational night lights lensing. The yellow galaxy in the center of the image enlarges and bends the light from the blue galaxy in the background of a large ring. Read more about the picture on NASA's website. (ESA / Hubble and NASA)
Gravitasjonslining is a phenomenon that occurs because not only matter, but also light bent by gravitational forces. This is predicted by Einstein's theory of relativity is well tested through observations. Just like a glass lens could magnify and distort objects, a lump of matter could magnify and distort light. Therefore, if we look at a distant galaxy and there is a large clump of dark matter between us and the galaxy, the galaxy could look distorted. How much and how distorted we can use to derive how the gravitational lens in the middle looks. This will tell us how much dark matter there is in the lens. Easily!
Illustration of gravitational lensing. The light from galaxies in the background are twisted and contorted by gravity from a galaxy cluster night lights that lies along the line of sight. The result is a somewhat distorted picture of the rear galaxies. Note that galaxies form a circular pattern around gravitasjosnslinsa. (Illustration: Michael Sachs)
Yes, indeed, when we have real luck and has a perfect location of galaxies and gravitational