Dark matter is a mysterious phenomenon. We do not know what it looks like or what it is made of. But physicists are convinced that it exists, because the effect of its gravitational pull can be observed in many examples in the cosmos. The visible universe - ourselves, the planets and stars - accounts for 25 percent of the total mass in the universe. The remaining 75 percent of its mass consists of dark matter. The fact that it interacts via gravity at least gives researchers a clue as to how heavy its particles might be. It was previously…

Current experiments that search for dark matter are mostly based on the idea that dark matter should somehow show up, i.e. by interacting with normal matter. Now, however, the only thing we really know about this important part of the universe is that an interaction with normal matter occurs via gravity. This is what first made researchers realize that dark matter exists. Is it perhaps because the search has so far been fruitless? Then a method could help, which researchers of the NIST and their colleagues presented now. "Our proposal is based purely on gravitational coupling, the only coupling…

One of the biggest mysteries of our universe is what is dark matter made of. Its existence is suggested by several astronomical observations, among them peculiarities in the rotation of galaxies. Dark matter would have to make up at least 63% of all matter in the universe and to date, physicists have no idea about its exact nature. All that is clear is that dark matter interacts with normal matter only via gravity. These could be, among other things, so-called WIMPs (Weakly Interacting Massive Particles), which would be considered cold dark matter. However, researchers are not making very quick…

The exact composition of 84 percent of all the matter in the universe is unknown. That is the portion, called dark matter, which neither emits radiation nor interacts with conventional matter that we already know of in any other way than through gravity. Cosmologists believe they can use the standard model of the universe, Lambda-CDM, to get to the bottom of dark matter. This model assumes that dark matter is “cold” (cold dark matter - CDM). In physics, “cold” means that something is moving slowly. So-called “WIMPs” (weakly interacting massive particles) would have to be previously unknown particles, heavier…

“When you have eliminated the impossible, whatever remains, however improbable, must be the truth,” the detective, Sherlock Holmes, says to Dr. Watson in “The Sign of the Four.” Cosmologists searching for dark matter, which should make up 85 percent of the universe’s mass, seem to be following a similar process right now. They are eliminating one component after another. Recently, they succeeded in eliminating two more possibilities. Dark matter is not made up of tiny black holes. This result was shown by astronomers with the help of the Japanese Subaru telescope. Their strategy was very interesting. According to theories…

The most important characteristic of dark matter is that it interacts only by way of gravity. And as the only one of the four fundamental forces, gravity is always attractive. Therefore, no matter where it occurs, dark matter must always collect at the mass center of the respective structure, regardless of whether it is a small galaxy or a giant galaxy cluster. But in reality, things look quite different: in galaxy clusters, dark matter exhibits the expected behavior, but in smaller galaxies it is distributed much more widely than it should be. This arrangement could be explained in that…