Invisible matter—one that does not emit and does not absorb light and that reveals itself by gravitation it generates—has been dubbed by astrophysicists dark, or exotic matter. It is ubiquitous, present everywhere, in individual galaxies and in galactic superclusters alike. In mass it far exceeds visible, ordinary matter. What is it really like? We cannot tell. It might be composed of some unknown elementary particles, or be in the form of small-mass black holes or hypothetical "worm-holes". This has been the subject of an English-written article by RAS Corresponding Member Igor Novikov, who is also a member of the Astrocosmic Center of the Moscow-based Lebedev Physics Institute, and the Niels Bohr International Academy (Copenhagen, Denmark). Translated into Russian by RAS Corresponding Member Viktor Abalkin, this article was carried in the Russian-language journal Earth and Universe. We follow with an English transcript. Dark matter is one of the mysteries of present-day cosmology. The discovery and research of this phenomenon has a rather long history. For as much as eighty-five years astrophysicists have been closely involved with this subject. Today this problem has come to the fore. Thirty and even twenty years ago astronomers maintained that the mass of dark matter was predominant in the universe and determined its dynamics and the curvature of its spacetime. Today we  know much  more. Observations within the range of anisotropy temperature measurements of the cosmic microwave background radiation (such radiation appeared immediately after the birth of the universe, and it carries important information) as well as data on the presence of helium and other light elements and on the structure of the universe—all this indicates that ordinary (baryonic)* matter is responsible for about 4 percent of the cosmic mass. So the stars, planets, gas, dust and we ourselves are composed of such visible matter, while the rest 96 percent is a "dark", exotic spe ... Читать далее