Search results
Results From The WOW.Com Content Network
A cyclic model (or oscillating model) is any of several cosmological models in which the universe follows infinite, or indefinite, self-sustaining cycles. For example, the oscillating universe theory briefly considered by Albert Einstein in 1930 theorized a universe following an eternal series of oscillations, each beginning with a Big Bang and ending with a Big Crunch; in the interim, the ...
The solutions of interest in stellar pulsation theory are the asymptotic solutions (as time tends towards infinity) because the time scale for the amplitude variations is generally very short compared to the evolution time scale of the star which is the nuclear burning time scale.
Pulsating variables, stars whose radius alternately expands and contracts as part of their natural evolutionary ageing processes. Eruptive variables, stars who experience eruptions on their surfaces like flares or mass ejections. Cataclysmic or explosive variables, stars that undergo a cataclysmic change in their properties like novae and ...
BPM 37093 was first observed to be a pulsating variable in 1992, [1] and in 1995 it was pointed out that this yielded a potential test of the crystallization theory. [9] In 2004, Antonio Kanaan and a team of researchers of the Whole Earth Telescope estimated, on the basis of these asteroseismological observations, that approximately 90% of the ...
The current belief is that the universe was built in a bottom-up fashion, meaning that the small anisotropies of the early universe acted as gravitational seeds for the structure observed today. Overdense regions attract more matter, whereas underdense regions attract less, and thus these small anisotropies, seen in the CMB, became the large ...
He established a number of theoretical results important in the study of an expanding universe. [2] In his 1934 monograph titled Relativity, Thermodynamics, and Cosmology, [ 15 ] Tolman demonstrated how black body radiation in an expanding universe cools but remains thermal – a key pointer toward the properties of the cosmic microwave ...
The theory explains that the universe will expand until all matter decays and ultimately turns to light. Since nothing in the universe would have any time or distance scale associated with it, the universe becomes identical with the Big Bang, resulting in a type of Big Crunch that becomes the next Big Bang, thus perpetuating the next cycle. [21]
The unqualified term instability strip usually refers to a region of the Hertzsprung–Russell diagram largely occupied by several related classes of pulsating variable stars: [1] Delta Scuti variables, SX Phoenicis variables, and rapidly oscillating Ap stars (roAps) near the main sequence; RR Lyrae variables where it intersects the horizontal branch; and the Cepheid variables where it crosses ...