The Big Bang theory is the prevailing cosmological model for the observable universe from the earliest known periods through its subsequent large-scale evolution. It explains the origin and evolution of the universe as we know it today.
Evidence for the Big Bang Theory
There are several lines of evidence that support the Big Bang theory:
Hubble's Law: The observation that galaxies are moving away from us, and the farther away they are, the faster they are moving. This suggests that the universe is expanding.
Cosmic Microwave Background (CMB) Radiation: The discovery of a pervasive background of microwaves that fills the universe in all directions. This radiation is thought to be the afterglow of the Big Bang.
Dark Ages: A period when the universe was filled with neutral hydrogen and helium, with no stars or galaxies.
Formation of the First Stars and Galaxies: The first stars and galaxies began to form, ending the Dark Ages.
Subsequent Large-Scale Evolution: The universe continued to evolve, leading to the formation of galaxies, stars, and planetary systems.
Implications of the Big Bang Theory
The Big Bang theory has several important implications:
Age of the Universe: The Big Bang theory provides an estimate of the age of the universe, currently believed to be around 13.8 billion years.
Cosmic Inflation: The theory of cosmic inflation suggests that the universe underwent a rapid and exponential expansion in the first moments after the Big Bang.
Formation of Elements: The Big Bang theory explains how the lightelementshydrogen, helium, and a small amount of lithium were formed in the early universe.
Structure Formation: The theory provides a framework for understanding the formation and evolution of large-scale structures in the universe, such as galaxies and galaxy clusters.
Overall, the Big Bang theory has withstood extensive observational and theoretical scrutiny, and it remains the most widely accepted model for the origin and evolution of the universe.
Energy - A. Energy is involved in all physical and chemical processes. It is conserved, and can be transformed from one form to another and into work. At the atomic and nuclear levels energy is not continuous but exists in discrete amounts. Energy and mass are related through Einstein's equation E=mc 2 . B. The properties of atomic nuclei are responsible for energy-related phenomena such as radioactivity, fission and fusion. C. Changes in entropy and energy that accompany chemical reactions influence reaction paths. Chemical reactions result in the release or absorption of energy. D. The theory of electromagnetism explains that electricity and magnetism are closely related. Electric charges are the source of electric fields. Moving charges generate magnetic fields. E. Waves are the propagation of a disturbance. They transport energy and momentum but do not transport matter.
Relate temperature to the average molecular kinetic energy.