Physics
General
- https://en.wikipedia.org/wiki/Experimental_physics - disciplines and sub-disciplines in the field of physics that are concerned with the observation of physical phenomena and experiments. Methods vary from discipline to discipline, from simple experiments and observations, such as the Cavendish experiment, to more complicated ones, such as the Large Hadron Collider.
- https://en.wikipedia.org/wiki/Theoretical_physics - employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena.
- https://en.wikipedia.org/wiki/Applied_physics - physics which is intended for a particular technological or practical use.[1] It is usually considered as a bridge or a connection between "pure" physics and engineering.
Spacetime
- https://en.wikipedia.org/wiki/World_line - object is the unique path of that object as it travels through 4-dimensional spacetime. The concept of "world line" is distinguished from the concept of "orbit" or "trajectory" (such as an orbit in space or a trajectory of a truck on a road map) by the time dimension, and typically encompasses a large area of spacetime wherein perceptually straight paths are recalculated to show their (relatively) more absolute position states — to reveal the nature of special relativity or gravitational interactions. The idea of world lines originates in physics and was pioneered by Hermann Minkowski. The term is now most often used in relativity theories
- https://en.wikipedia.org/wiki/Theory_of_relativity - or relativity in physics, usually encompasses two theories by Albert Einstein: special relativity and general relativity. (The word relativity can also be used in the context of an older theory, that of Galilean invariance.)
- http://en.wikipedia.org/wiki/Special_relativity - the accepted physical theory regarding the relationship between space and time. It is based on two postulates: (1) that the laws of physics are invariant (i.e., identical) in all inertial systems (non-accelerating frames of reference); and (2) that the speed of light in a vacuum is the same for all observers, regardless of the motion of the light source. It was originally proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".[1] The inconsistency of classical mechanics with Maxwell’s equations of electromagnetism led to the development of special relativity, which corrects classical mechanics to handle situations involving motions nearing the speed of light. As of today, special relativity is the most accurate model of motion at any speed. Even so, classical mechanics is still useful (due to its simplicity and high accuracy) as an approximation at small velocities relative to the speed of light.
Special relativity implies a wide range of consequences, which have been experimentally verified including length contraction, time dilation, relativistic mass, mass–energy equivalence, a universal speed limit, and relativity of simultaneity. It has replaced the conventional notion of an absolute universal time with the notion of a time that is dependent on reference frame and spatial position. Rather than an invariant time interval between two events, there is an invariant spacetime interval. Combined with other laws of physics, the two postulates of special relativity predict the equivalence of mass and energy, as expressed in the mass–energy equivalence formula E = mc2, where c is the speed of light in vacuum.
A defining feature of special relativity is the replacement of the Galilean transformations of classical mechanics with the Lorentz transformations. Time and space cannot be defined separately from one another. Rather space and time are interwoven into a single continuum known as spacetime. Events that occur at the same time for one observer could occur at different times for another. The theory is called "special" because it applied the principle of relativity only to the special case of inertial reference frames. Einstein later published a paper on general relativity in 1915 to apply the principle in the general case, that is, to any frame so as to handle general coordinate transformations, and gravitational effects.
As Galilean relativity is now considered an approximation of special relativity valid for low speeds, special relativity is considered an approximation of the theory of general relativity valid for weak gravitational fields. The presence of gravity becomes undetectable at sufficiently small-scale, free-falling conditions. General relativity incorporates noneuclidean geometry, so that the gravitational effects are represented by the geometric curvature of spacetime. Contrarily, special relativity is restricted to flat spacetime. The geometry of spacetime in special relativity is called Minkowski space. A locally Lorentz invariant frame that abides by special relativity can be defined at sufficiently small scales, even in curved spacetime.
Galileo Galilei had already postulated that there is no absolute and well-defined state of rest (no privileged reference frames), a principle now called Galileo's principle of relativity. Einstein extended this principle so that it accounted for the constant speed of light,[5] a phenomenon that had been recently observed in the Michelson–Morley experiment. He also postulated that it holds for all the laws of physics, including both the laws of mechanics and of electrodynamics.
- https://en.wikipedia.org/wiki/Introduction_to_special_relativity
- Albert Einstein's Theory of Relativity - In Words of Four Letters or Less
- https://en.wikipedia.org/wiki/History_of_special_relativity
- http://en.wikipedia.org/wiki/General_relativity - a theory of gravitation that was developed by Albert Einstein between 1907 and 1915, with contributions by many others after 1915. According to general relativity, the observed gravitational attraction between masses results from the warping of space and time by those masses.
- https://en.wikipedia.org/wiki/Einstein_field_equations - a set of 10 equations in Albert Einstein's general theory of relativity which describe the fundamental interaction of gravitation as a result of spacetime being curved by matter and energy. First published by Einstein in 1915 as a tensor equation, the EFE equate local spacetime curvature (expressed by the Einstein tensor) with the local energy and momentum within that spacetime (expressed by the stress–energy tensor).
- https://en.wikipedia.org/wiki/Geodesics_in_general_relativity - generalizes the notion of a "straight line" to curved spacetime. Importantly, the world line of a particle free from all external, non-gravitational force, is a particular type of geodesic. In other words, a freely moving or falling particle always moves along a geodesic. In general relativity, gravity can be regarded as not a force but a consequence of a curved spacetime geometry where the source of curvature is the stress–energy tensor (representing matter, for instance). Thus, for example, the path of a planet orbiting around a star is the projection of a geodesic of the curved 4-D spacetime geometry around the star onto 3-D space.
- Real-World Relativity: The GPS Navigation System [2]
- General Relativity in the Global Positioning System
photons don't know time; time moves at the speed of light.
Energy
to move
- https://en.wikipedia.org/wiki/Specific_energy - is energy per unit mass. It is used to quantify, for example, stored heat or other thermodynamic properties of substances such as specific internal energy, specific enthalpy, specific Gibbs free energy, and specific Helmholtz free energy. It may also be used for the kinetic energy or potential energy of a body. Specific energy is an intensive property, whereas energy and mass are extensive properties. The SI unit for specific energy is the joule per kilogram (J/kg).
- https://en.wikipedia.org/wiki/Energy_condition - one of various alternative conditions which can be applied to the matter content of the theory, when it is either not possible or desirable to specify this content explicitly. The hope is then that any reasonable matter theory will satisfy this condition or at least will preserve the condition if it is satisfied by the starting conditions.
In general relativity, energy conditions are often used (and required) in proofs of various important theorems about black holes, such as the no hair theorem or the laws of black hole thermodynamics.
- https://en.wikipedia.org/wiki/Physical_constant - a physical quantity that is generally believed to be both universal in nature and constant in time. It can be contrasted with a mathematical constant, which is a fixed numerical value, but does not directly involve any physical measurement. There are many physical constants in science, some of the most widely recognized being the speed of light in vacuum c, the gravitational constant G, Planck's constant h, the electric constant ε0, and the elementary charge e. Physical constants can take many dimensional forms: the speed of light signifies a maximum speed limit of the Universe and is expressed dimensionally as length divided by time; while the fine-structure constant α, which characterizes the strength of the electromagnetic interaction, is dimensionless.
- https://en.wikipedia.org/wiki/Elementary_charge - usually denoted as e or sometimes q, is the electric charge carried by a single proton, or equivalently, the negation (opposite) of the electric charge carried by a single electron
Forces and fields
Electromagnetism
- https://en.wikipedia.org/wiki/Classical_electromagnetism
- https://en.wikipedia.org/wiki/Quantum_electrodynamics - relativistic quantum field theory of electrodynamics
- https://en.wikipedia.org/wiki/Electromagnetic_wave
- https://en.wikipedia.org/wiki/Electromagnetic_radiation
- https://en.wikipedia.org/wiki/Radiant_energy - the energy of electromagnetic radiation
- https://en.wikipedia.org/wiki/Coulomb's_law - or Coulomb's inverse-square law, is a law of physics describing the electrostatic interaction between electrically charged particles. The law was first published in 1785 by French physicist Charles Augustin de Coulomb and was essential to the development of the theory of electromagnetism. It is analogous to Isaac Newton's inverse-square law of universal gravitation. Coulomb's law can be used to derive Gauss's law, and vice versa. The law has been tested heavily, and all observations have upheld the law's principle.
Strong nuclear
Weak nuclear
Gravity
- A rubber sheet can be mapped to a scalar theory of gravity
- Relativity is a tensor field theory
- https://en.wikipedia.org/wiki/Quantum_gravity - field of theoretical physics that seeks to describe the force of gravity according to the principles of quantum mechanics
- https://en.wikipedia.org/wiki/Graviton - massless spin-2 boson
- https://news.ycombinator.com/item?id=8283629
- http://mobile.sheridanc.on.ca/~claassen/Gravity/Gravity.html [4]
Other
Quantum Mechanics
to reorder
- https://en.wikipedia.org/wiki/Quantum_mechanics
- https://en.wikipedia.org/wiki/History_of_quantum_mechanics
- https://en.wikipedia.org/wiki/Quantum
- https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory - In addition to a wavefunction on the space of all possible configurations, it also postulates an actual configuration that exists even when unobserved. The evolution over time of the configuration (that is, of the positions of all particles or the configuration of all fields) is defined by the wave function via a guiding equation.
- https://en.wikipedia.org/wiki/Planck_length
- https://en.wikipedia.org/wiki/Planck_time -the time it would take a photon traveling at the speed of light to cross a distance equal to one Planck length
- https://en.wikipedia.org/wiki/Planck_epoch - the earliest period of time in the history of the universe, from zero to approximately 10−43 seconds (Planck time)
- https://en.wikipedia.org/wiki/Planck_constant - quantum of action in quantum mechanics. first described as the proportionality constant between the energy (E) of a photon and the frequency (ν) of its associated electromagnetic wave
- https://en.wikipedia.org/wiki/Quantum_number
- https://en.wikipedia.org/wiki/Quantization_(physics)
- https://en.wikipedia.org/wiki/Quantum_spacetime - a generalization of the usual concept of spacetime in which some variables that ordinarily commute are assumed not to commute and form a different Lie algebra. The choice of that algebra still varies from theory to theory. As a result of this change some variables that are usually continuous may become discrete. Often only such discrete variables are called "quantized"; usage varies. The idea of quantum spacetime was proposed in the early days of quantum theory by Heisenberg and Ivanenko as a way to eliminate infinities from quantum field theory. The germ of the idea passed from Heisenberg to Rudolf Peierls, who noted that electrons in a magnetic field can be regarded as moving in a quantum space-time, and to Robert Oppenheimer, who carried it to Hartland Snyder, who published the first concrete example. Snyder's Lie algebra was made simple by C. N. Yang in the same year.
- https://en.wikipedia.org/wiki/Symmetry_in_quantum_mechanics
- https://en.wikipedia.org/wiki/Spontaneous_symmetry_breaking
- https://en.wikipedia.org/wiki/Chirality_(physics) - A chiral phenomenon is one that is not identical to its mirror image
- https://en.wikipedia.org/wiki/Anomaly_(physics) - the failure of a symmetry of a theory's classical action to be a symmetry of any regularization of the full quantum theory
- https://en.wikipedia.org/wiki/Charge_(physics)
- https://en.wikipedia.org/wiki/Isospin - a quantum number related to the strong interaction
- https://en.wikipedia.org/wiki/Strangeness
- https://en.wikipedia.org/wiki/Charm_(quantum_number)
- https://en.wikipedia.org/wiki/Wavefunction
- https://en.wikipedia.org/wiki/Wavefunction_collapse
- https://en.wikipedia.org/wiki/Measurement_in_quantum_mechanics
- https://en.wikipedia.org/wiki/Quantum_tomography - the process of reconstructing the quantum state for a source of quantum systems by measurements on the systems coming from the source
- http://en.wikipedia.org/wiki/Renormalization - any of a collection of techniques used to treat infinities arising in calculated quantities.
- https://en.wikipedia.org/wiki/Perturbation_theory_(quantum_mechanics)
- https://en.wikipedia.org/wiki/Virtual_particles
- https://en.wikipedia.org/wiki/Feynman_diagram
- http://arstechnica.com/science/2013/12/a-quantum-revolution-against-feynman-diagrams/
- https://en.wikipedia.org/wiki/Multipole_expansion - a mathematical series representing a function that depends on angles — usually the two angles on a sphere
- https://en.wikipedia.org/wiki/Quadrupole
- https://en.wikipedia.org/wiki/Probability_amplitude
- https://en.wikipedia.org/wiki/Scattering_amplitude
- https://en.wikipedia.org/wiki/Scattering_length
Quantum Field Theory
to sort
there are no particles, only fields
- https://en.wikipedia.org/wiki/Scalar_field
- https://en.wikipedia.org/wiki/Vector_field - an assignment of a vector to each point in a subset of Euclidean space
- https://en.wikipedia.org/wiki/Spinor_field
- Understanding Quantum Field Theory
- YouTube: Understand Physics: Quantum Mechanics vs Quantum Field Theory
- https://en.wikipedia.org/wiki/Electroweak_interaction
- https://en.wikipedia.org/wiki/Electroweak_scale
- https://en.wikipedia.org/wiki/False_vacuum - a false vacuum is a metastable sector of space that appears to be a perturbative vacuum, but is unstable due to instanton effects that may tunnel to a lower energy state.
- https://en.wikipedia.org/wiki/Lagrangian_mechanics - is a re-formulation of classical mechanics using the principle of stationary action (also called the principle of least action, and applies to systems whether or not they conserve energy or momentum, and it provides conditions under which energy, momentum or both are conserved
- https://en.wikipedia.org/wiki/Gauge_theory - a type of field theory in which the Lagrangian is invariant under a continuous group of local transformations.
- https://en.wikipedia.org/wiki/Nontechnical_introduction_to_gauge_theory
- R. P. Feynman and his problems in QCD/QED
- Particle Interactions, QED and QCD: An Introduction - Part 1
Standard Model
Statistics
- https://en.wikipedia.org/wiki/Particle_statistics - a statistical ensemble that emphasizes properties of a large system as a whole at the expense of knowledge about parameters of separate particles
- https://en.wikipedia.org/wiki/Quantum_statistical_mechanics - a statistical ensemble (probability distribution over possible quantum states) is described by a density operator S, which is a non-negative, self-adjoint, trace-class operator of trace 1 on the Hilbert space H describing the quantum system
- https://en.wikipedia.org/wiki/Hilbert_space - generalizes the notion of Euclidean space, extends the methods of vector algebra and calculus from the two-dimensional Euclidean plane and three-dimensional space to spaces with any finite or infinite number of dimensions, an abstract vector space possessing the structure of an inner product that allows length and angle to be measured
- https://en.wikipedia.org/wiki/Generation_(particle_physics)
- https://en.wikipedia.org/wiki/Flavour_(particle_physics)
Mass
Particles
- https://en.wikipedia.org/wiki/List_of_particles
- https://en.wikipedia.org/wiki/File:Particle_overview.svg
- http://pdg.lbl.gov/ The Review of Particle Physics
Bosons
- https://en.wikipedia.org/wiki/Force_carrier - particles that give rise to forces between other particles. These particles are bundles of energy (quanta) of a particular kind of field. There is one kind of field for every species of elementary particle.
- https://en.wikipedia.org/wiki/Vector_boson - a boson with the spin quantum number equal to 1
- https://en.wikipedia.org/wiki/Gauge_boson - forms of vector boson force carrier particles that mediate the electromagnetic, weak and strong interactions
- https://en.wikipedia.org/wiki/Photon - carry the electromagnetic interaction
- https://en.wikipedia.org/wiki/W_and_Z_bosons - carry the weak interaction
- https://en.wikipedia.org/wiki/Gluon - strong interaction
- https://en.wikipedia.org/wiki/Vector_meson - a meson with total spin 1 and odd parity
- https://en.wikipedia.org/wiki/Pseudovector_meson - a meson with total spin 1 and even parity
- https://en.wikipedia.org/wiki/Pseudoscalar_meson - a meson with total spin 0 and odd parity
Fermions
- https://en.wikipedia.org/wiki/Fermion - any particle characterized by Fermi–Dirac statistics and following the Pauli exclusion principle; fermions include all quarks and leptons, as well as any composite particle made of an odd number of these, such as all baryons and many atoms and nuclei. spin-1⁄2 particle. Composite fermions, such as protons and neutrons, are key building blocks of everyday matter
- https://en.wikipedia.org/wiki/Lepton - does not undergo strong interactions
- http://en.wikipedia.org/wiki/Electron_configuration
- http://en.wikipedia.org/wiki/Electron_shell
- http://en.wikipedia.org/wiki/Valence_electron
- https://en.wikipedia.org/wiki/Quark
- https://en.wikipedia.org/wiki/Baryon - composite subatomic particle made up of three quarks
- https://en.wikipedia.org/wiki/Hadron
- http://en.wikipedia.org/wiki/Neutron
- http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.112.242502
- https://en.wikipedia.org/wiki/Up_quark
- https://en.wikipedia.org/wiki/Down_quark
- https://en.wikipedia.org/wiki/Strange_quark
- https://en.wikipedia.org/wiki/Bottom_quark
- https://en.wikipedia.org/wiki/Top_quark
Atomic
- https://en.wikipedia.org/wiki/Atomic_physics - deals with the atom as a system consisting of a nucleus and electrons
- https://en.wikipedia.org/wiki/Atom - a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons.
- https://en.wikipedia.org/wiki/Atomic_nucleus - contains a mix of positively charged protons and electrically neutral neutrons (except in the case of hydrogen-1, which is the only stable nuclide with no neutrons)
- https://en.wikipedia.org/wiki/Nucleon
- https://en.wikipedia.org/wiki/Atomic_number - the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus
- https://en.wikipedia.org/wiki/Chemical_element
- https://en.wikipedia.org/wiki/Periodic_table
- http://www.periodictable.com/
- http://www.periodicvideos.com/
- http://table.minutephysics.com/
- https://en.wikipedia.org/wiki/Nuclear_physics - considers atomic nuclei alone
- https://en.wikipedia.org/wiki/Radiation
- https://en.wikipedia.org/wiki/Radioactive
- https://en.wikipedia.org/wiki/Radioactive_decay
- https://en.wikipedia.org/wiki/Half-life
- https://en.wikipedia.org/wiki/Ion - an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving the atom a net positive or negative electrical charge
Matter
- https://en.wikipedia.org/wiki/Fluid
- https://en.wikipedia.org/wiki/Liquid
- https://en.wikipedia.org/wiki/Gas
- https://en.wikipedia.org/wiki/Plasma_(physics)
- https://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_condensate
- https://en.wikipedia.org/wiki/Mpemba_effect - the observation that, in some circumstances, warmer water can freeze faster than colder water
- https://en.wikipedia.org/wiki/Cold_dark_matter
- https://en.wikipedia.org/wiki/Warm_dark_matter
- https://en.wikipedia.org/wiki/Hot_dark_matter
- https://en.wikipedia.org/wiki/Antiparticle
- https://en.wikipedia.org/wiki/Antimatter
- https://en.wikipedia.org/wiki/Electron%E2%80%93positron_annihilation
- https://en.wikipedia.org/wiki/Antihydrogen
- https://en.wikipedia.org/wiki/Ion - an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving the atom a net positive or negative electrical charge
- https://medium.com/the-physics-arxiv-blog/high-temperature-superconductivity-record-smashed-by-sulphur-hydride-c853795079bb [8]
Accelerators
Molecular
Cosmology
See also Space
- https://en.wikipedia.org/wiki/Cosmogony
- https://en.wikipedia.org/wiki/Age_of_the_universe
- https://en.wikipedia.org/wiki/Chronology_of_the_universe
- https://en.wikipedia.org/wiki/Cosmological_principle - an axiom that embodies the working assumption or premise that the distribution of matter in the universe is homogeneous and isotropic when viewed on a large enough scale, since the forces are expected to act uniformly throughout the universe
- https://en.wikipedia.org/wiki/Lambda-CDM_model
- https://en.wikipedia.org/wiki/Inflation_(cosmology)
- https://en.wikipedia.org/wiki/Inflaton - scalar field
- https://en.wikipedia.org/wiki/Inflationary_epoch
- https://en.wikipedia.org/wiki/Cosmic_neutrino_background - a relic of the big bang, decoupled from matter when the universe was 2 seconds old
- https://en.wikipedia.org/wiki/Neutrino_decoupling - the epoch at which neutrinos ceased interacting with baryonic matter
- https://en.wikipedia.org/wiki/Cosmic_microwave_background - decoupled from matter when the universe was 379,000 years old
- https://en.wikipedia.org/wiki/Interstellar_medium - the matter that exists in the space between the star systems in a galaxy, includes gas in ionic, atomic, and molecular form, dust, and cosmic rays
- https://en.wikipedia.org/wiki/Interstellar_cloud - the generic name given to an accumulation of gas, plasma and dust in our and other galaxies. Put differently, an interstellar cloud is a denser-than-average region of the interstellar medium
- https://en.wikipedia.org/wiki/Molecular_cloud - type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen
- https://en.wikipedia.org/wiki/Galaxy
- https://en.wikipedia.org/wiki/Galaxy_morphological_classification
- https://en.wikipedia.org/wiki/Spiral_galaxy
- https://en.wikipedia.org/wiki/Bulge_(astronomy) - tightly packed group of stars within a larger formation, almost exclusively refers to the central group of stars found in most spiral galaxies
- https://en.wikipedia.org/wiki/Galactic_Center
- https://en.wikipedia.org/wiki/Globular_cluster
- https://en.wikipedia.org/wiki/Galaxy_cluster
- https://en.wikipedia.org/wiki/Intracluster_medium - superheated plasma present at the center of a galaxy cluster
- https://medium.com/starts-with-a-bang/ask-ethan-45-how-deep-does-the-multiverse-go-70820b852ee8
- http://www.quantamagazine.org/20141103-in-a-multiverse-what-are-the-odds/ [9]
- http://www.wired.com/2014/11/check-universe-exist/ [10]
Quasar
Beyond the Standard Model
String theory
- https://en.wikipedia.org/wiki/String_theory
- https://en.wikipedia.org/wiki/Membrane_(M-theory)
- https://www.superstringtheory.com/
- https://xkcd.com/171/
- arxiv.org: Nonlocality in string theory
- https://en.wikipedia.org/wiki/Bosonic_string_theory
- https://en.wikipedia.org/wiki/Superstring_theory
- https://whystringtheory.com/
Other
- https://en.wikipedia.org/wiki/Constructor_theory - expresses physical laws in terms of the physical transformations or changes which the laws make possible. By allowing the existence of counterfactuals, statements about transformations which may prove false, it is also able to describe information in terms of known physical laws.
- http://www.scientificamerican.com/article/a-meta-law-to-rule-them-all-physicists-devise-a-theory-of-everything/
- https://en.wikipedia.org/wiki/Supergravity - a field theory that combines the principles of supersymmetry and general relativity
- https://en.wikipedia.org/wiki/An_Exceptionally_Simple_Theory_of_Everything
- Garrett Lisi: A theory of everything - 2008
- The Geometry of Particle Physics: Garrett Lisi at TEDxMaui 2013
- A Jewel at the Heart of Quantum Physics [13]
- The Unitarihedron: The Jewel at the Heart of Quantum Computing [14]
- https://en.wikipedia.org/wiki/Mathematical_universe_hypothesis
- http://discovermagazine.com/2013/dec/13-math-made-flesh