Dark matter is the most mysterious substance in the universe. She is so mysterious that no one still knows for sure if she really exists. This unique substance, of which perhaps 80% of our Universe is composed, does not interact with the surrounding world in any way: it can neither be seen nor touched. Despite this sad fact, in honor of this not yet open substance, even its own holiday was established - the Day of Dark Matter, celebrated by scientists on October 31. Well, a celebration in honor of dark matter is far from the only oddity of such a mysterious substance.
What is dark matter?
In the 1930s, a Swiss astronomer named Fritz Zwicky noticed that galaxies in a distant cluster were orbiting each other much faster than they should. The scientist suggested that an invisible substance, which he called dark matter, can gravitationally attract these galaxies and somehow stick them together, preventing them from scattering in different directions of the Universe.
Almost 90 years have passed, but researchers have not been able to get close to the clue to the nature of dark matter. The only thing we know for sure is that this mysterious material can be found throughout the cosmos and that it is much more abundant in the universe than the matter we see. Well, perhaps the inability to understand the composition of a mysterious substance can be considered the first oddity of a unique substance.
Can dark matter be detected?
If dark matter is incapable of interacting with ordinary matter, then can we somehow detect it? Probably, this is the question that the scientists who conducted experiment after experiment asked themselves in the hope of finding that very cherished particle of dark matter. Despite years of searching, no traces of dark matter have been found on Earth.
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You probably know from your high school physics course that ordinary matter consists of particles such as protons and electrons, as well as a whole zoo of more exotic particles such as neutrinos, muons and pions. While trying to find dark matter, researchers wondered if this mysterious substance could be as complex as ordinary matter.
According to Harvard University researcher Andrei Katz, there is no reason to believe that all dark matter in the universe is built from one type of particle. Thus, dark protons can combine with dark electrons to form dark atoms, creating configurations as diverse and interesting as those in the visible world.
Along with additional dark matter particles, there is the possibility that it experiences forces similar to those experienced by ordinary matter. Some researchers were looking for "dark photons" that look like photons that appear between normal particles. If one day they are discovered, then such a discovery will mark a new stage in the study of the properties of the universe.
Is there dark matter in our galaxy?
Since there is much more dark matter in the Universe than ordinary matter, it is often said that it is it that is a kind of governing force that organizes such large structures as galaxies and galaxy clusters.
That is why the discovery of a galaxy called NGC 1052-DF2 came as a complete surprise, since this structure does not contain dark matter at all. As for the Milky Way galaxy, scientists have found the main cluster of dark matter right in the center of our galaxy. What caused such a strange and inhomogeneous distribution of a mysterious substance in the Universe is still unknown. However, if someday this secret is revealed, humanity may well become a witness to the development of a new science.
Daria Eletskaya