ASTR 123 Assignment Example | Topics and Well Written Essays - 500 words

ASTR 123 - Assignment Example On the other hand, there seems to be much matter in the universe such that the universe may be in a continuous state of expansion The four root elements of the universe air, Earth, Water and fire are the main manifestation of material substances and physical manifestations. The interaction of these four elements is associated with two basic great life energies namely Love and Strife. The four elements combine and separate under opposing forces of Love and Strife to produce the changing world together with the continuous manifold of objects and qualities. The stars have to be made of a perfect and exalted substance because of evidences available in various natural motions. Some bodies move in straight lines while others move in circular orbits. According to Aristotle it is natural for objects moving in circular orbits to be spherical and that the world is unique. Dark matter is non- baryonic particles that do not collide with photons and pass through protons and neutrons. Hot dark matter is composed of particles that have zero or near-zero mass. The Special Theory of Relativity requires that massless particles move at the speed of light and that nearly massless particles move at nearly the speed of light. Thus, such very low mass particles must move at very high velocities and thus form very hot gases which are the stars Prior to this era of the Universe, neutrons and protons were rapidly changing into each other through the emission and absorption of neutrinos. Now the Universe has expanded and cooled to the point where that process slowed down. When the Universe was sufficiently hot and dense, there were so many electrons and anti-neutrinos hitting protons and changing them into neutrons. As the Universe kept expanding and cooling, the mean energy level of the particles dropped and so did the rate of neutrinos hitting protons and converting them into neutrons. The neutrinos and anti-neutrinos decoupled from the rest of the matter and