DARK MATTER & DARK ENERGY | VIDEO
DARK MATTER – MYTHS AND REALITY
Lecture by Pr. A.V. Zasov, teaching astrophysics and astronomy at the Moscow State University Lomonosov.
DARK MATTER AND DARK ENERGY (2015)
Dark matter in astronomy and cosmology, as well as in theoretical physics, is a hypothetical form of matter that does not emit electromagnetic radiation and does not interact with it. This property of this form of substance makes it impossible for it to be observed directly. Conclusion about the existence of dark matter is made on the basis of numerous, consistent with each other, but indirect signs of the behaviour of astrophysical objects and by their gravitational effects. The discovery of the nature of dark matter would help solve the problem of hidden mass, which, in particular, is linked to the abnormally high speed of rotation of the outer regions of galaxies. Dark energy in cosmology is a kind of energy, a mathematical model of the Universe, for the sake of explaining its observed accelerated expansion.
There are two ways of explaining the essence of dark energy: the dark energy is the cosmological constant, describing the constant energy density filling evenly the space in the Universe (in other words, a non-zero energy and vacuum pressure is postulated); or, dark energy is some sort of quintessence, a dynamic field, an energy density which can vary in time and space.
To date, all known reliable observational data are not contrary to the first hypothesis, so it is accepted in cosmology as a standard one. The final choice between the two options requires high-precision measurements of the speed of expansion of the Universe, to understand how this speed varies with time. The rate of expansion of the Universe is describes by its cosmological equation of state. The resolution of equations of state for dark energy is one of the most important tasks of modern observational cosmology.
Dark energy must also constitute a significant part of the so-called hidden mass of the Universe. According to observational data from Plank, published in March 2013, the total mass-energy of the observable Universe to 95.1 % consists of dark energy (68.3 %) and dark matter (26.8 %).
ТЁМНАЯ МАТЕРИЯ И ЧЁРНЫЕ ДЫРЫ (2014)
Lecture by Academician A.M. Cherepaschuk.
ТЁМНАЯ ЭНЕРГИЯ И ТЁМНАЯ МАТЕРИЯ ВО ВСЕЛЕННОЙ (2013) (In Russian)
Lecture by Grigory M. Vereshkov, Head of the laboratory of physics of fundamental interactions of the South Federal University, Russia.
ТЁМНАЯ ЭНЕРГИЯ ВО ВСЕЛЕННОЙ (ПРОГРАММА АЛЕКСАНДРА ГОРДОНА). (2001) (In Russian)
Discussion with the member-correspondant of the Russian Academy of Sciences Alexey Starobinsky.
About the so-called dark energy, which, as shown by the recent discoveries of physics, forms the bulk of the energy density in the modern Universe.