Search results
Results From The WOW.Com Content Network
where t is the age of the universe, is the speed of light and r e is the classical electron radius. Hence, in units where c = 1 and r e = 1, the age of the universe is about 10 40 units of time. This is the same order of magnitude as the ratio of the electrical to the gravitational forces between a proton and an electron:
Advanced Placement (AP) Biology (also known as AP Bio) is an Advanced Placement biology course and exam offered by the College Board in the United States. For the 2012–2013 school year, the College Board unveiled a new curriculum with a greater focus on "scientific practices".
This metric has only two undetermined parameters. An overall dimensionless length scale factor R describes the size scale of the universe as a function of time (an increase in R is the expansion of the universe), [152] and a curvature index k describes the geometry.
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]
Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its origin, structure, evolution, and ultimate fate. [1]
The absurd universe: Our universe just happens to be the way it is. The unique universe: There is a deep underlying unity in physics that necessitates the Universe being the way it is. A Theory of Everything will explain why the various features of the Universe must have exactly the values that have been recorded.
A cosmological horizon is a measure of the distance from which one could possibly retrieve information. [1] This observable constraint is due to various properties of general relativity, the expanding universe, and the physics of Big Bang cosmology.
Daily experiences of matter and the Universe are characterized by very low energy. For example, the photon energy of visible light is about 1.8 to 3.2 eV. Similarly, the bond-dissociation energy of a carbon-carbon bond is about 3.6 eV. This is the energy scale manifesting at the macroscopic level, such as in chemical reactions.