There are several pieces of evidence dealing with electrical, optical, mechanical, and thermal properties of solids. To list a few:
The Kronig-Penney model is a simplified one-dimensional periodic potential that helps understand electronic band structures in solids. By solving the Schrödinger equation within this model, one can see how energy bands form due to the periodic potential experienced by electrons in a crystal lattice. This model provides insights into the origin of band gaps, allowed and forbidden energy bands, and the behavior of electrons in solids.
the big band theory is a theory which explains the evolvement of the universe which was hot and very dense at 1300 to 1500 MILLION YEARS AGO ......TSHWANE UNIVERSITY OF TECHNOLOGY STUDENT
The Big Bang Theory is the prevailing scientific theory explaining the origin of the universe. It proposes that the universe began as a hot, dense point around 13.8 billion years ago and has been expanding ever since. This theory is supported by evidence such as the cosmic microwave background radiation and the observed redshift of galaxies.
The big band theory
Free Electron Theory:This theory tells that, metals conduct electricity because of the presence of free electrons in it. The outermost shells of metal atoms will be loosely bound with their nucleus. So the electrons in it are free to move anywhere in the solid.These electrons are called free electrons and they are responsible for the conduction of electricity.Band theory of solids:A solid is assumed to contain many bands in which the electrons in it are packed. The most important are valence band and conduction band. The energy of electrons in these bands will be different.The difference in energies of valence band and conduction band determines whether the solid is a conductor, semi - conductor or insulator.For insulators, the difference between energies of them ( energy gap ) will be very high, and for conductor, these bands overlap each other.The conduction band carries the electrons that conduct electricity, but the valence band has all the electrons in the ground state. Whether they go into the conduction band depends on the temperature and the energy gap between the bands. In a conductor, these bands overlap, and hence many electrons can become conducting. Thus, Band Theory explains distinction between metals and insulators, which Free Electron theory cannot do (since it assumes all valence electrons become conducting). Calculations are be performed to see which materials will have big energy gaps and which will have overlapping bands.
Simon L. Altmann has written: 'Induced Representations in Crystals and Molecules' -- subject(s): Crystallography, Mathematical, Mathematical Crystallography, Molecular crystals, Space groups 'Is Nature Supernatural? A Philosophical Exploration of Science and Nature' 'Band theory of solids' -- subject(s): Group theory, Symmetry (Physics), Energy-band theory of solids
Energy band theory is the theoretical framework used to explain the electronic structure of solids in terms of energy bands. It describes how electrons in a solid can only occupy certain energy levels, forming bands of allowed energy states. These bands can be either filled with electrons (valence band) or empty (conduction band), with a band gap separating them.
Karl-Fredrik Berggren has written: 'Effects of electron structure and correlation on equations of state of solids' -- subject(s): Electronic structure, Energy-band theory of solids
Valence band theory describes the electronic structure of solids based on the energy levels of electrons in the valence band of the material. On the other hand, crystal field theory focuses on the interaction between the d-orbitals of transition metal ions and the surrounding ligands, which results in the splitting of d-orbitals into different energy levels.
The Evidence - band - was created in 2000.
The Evidence - band - ended in 2007.
Daniel D. Pollock has written: 'Physical properties of materials for engineers' -- subject(s): Materials, Solids 'The theory and properties of thermocouple elements' -- subject(s): Thermocouples 'Thermoelectricity' -- subject(s): Thermocouples, Thermoelectric materials, Thermoelectricity 'Electrical conduction in solids' -- subject(s): Electric conductivity, Energy-band theory of solids
decreased width of the H band during contraction
No such thing as the big band theory
Jesuit priest Georges LeMaitre was the first to propose that we exist in an expanding universe, and that observable evidence exists to support this idea.
The rubber band theory suggests that the universe expanded rapidly from a very dense and hot state, also known as the Big Bang. It compares this expansion to stretching a rubber band, where the further apart galaxies are, the more they move away from each other. This theory is supported by observational evidence such as the cosmic microwave background radiation and the redshift of galaxies.
The Kronig-Penney model is a simplified one-dimensional periodic potential that helps understand electronic band structures in solids. By solving the Schrödinger equation within this model, one can see how energy bands form due to the periodic potential experienced by electrons in a crystal lattice. This model provides insights into the origin of band gaps, allowed and forbidden energy bands, and the behavior of electrons in solids.