Warped Passages - Lisa Randall [229]
proton An ingredient of the atomic nucleus in which two up quarks and a down quark are tightly bound to each other.
QCD (quantum chromodynamics) The quantum field theory of the strong force.
QED (quantum electrodynamics) The quantum field theory of electromagnetism.
quantum A discrete unbreakable unit of a measurable quantity; the smallest unit of that quantity.
quantum contribution A contribution to a physical process due to virtual particles.
quantum field theory The theory used to study particle physics with which one can calculate the rates for processes in which particles can interact, be created, or be destroyed. According to quantum field theory, fluctuations of fields manifest themselves as particles.
quantum gravity A theory of gravity that incorporates both quantum mechanics and general relativity.
quantum mechanics The theory that is based on the assumption that all matter consists of discrete elementary particles that have associated wavefunctions.
quark An elementary fermionic particle that experiences the strong force.
quasicrystal A solid material whose crystalline structure is derived from higher dimensions.
redshift The lowering of frequency of a wave when the object emitting the wave is either moving away (Doppler redshift) or is slowed down by a strong gravitational field (gravitational redshift).
relativity One of Einstein’s two theories of spacetime: special relativity, which unifies space and time, and general relativity, which explains gravity as the curvature of spacetime.
renormalization group A calculation technique for relating quantities that apply in different energy or distance regimes.
rotational invariance The independence of the results of experiments on orientation (or direction).
selectron The superpartner of the electron.
sequestering The physical separation of different elementary particle types in extra dimensions.
singularity A region where a mathematical description of an object breaks down because some quantity becomes infinite.
slepton The superpartner of a lepton.
spacetime The concept that unifies space and time into a single framework; the mathematical formulation of the region where physical processes can occur.
special relativity The theory of gravity that describes motion in inertial frames of reference.
spectral lines Discrete frequencies at which non-ionized atoms emit or absorb light.
spectrum A function that gives the spread of energy emitted across all frequencies.
spin See intrinsic spin.
spontaneously broken symmetry Symmetry that is preserved by physical laws but broken by the actual physical state of a system.
squark The superpartner of a quark.
Standard Model (of particle physics) The effective theory that describes all known particles and nongravitational forces and the interactions among them.
strange quark A short-lived, heavier version of the down quark.
string A one-(spatial)dimensional extended object whose oscillations constitute elementary particles.
string coupling A quantity that determines the strength of the interaction between strings.
string theory The theory that posits that the ingredients of the universe are fundamental strings and which should consistently incorporate quantum mechanics and general relativity.
strong force One of the four known forces; the strong force is responsible for binding quarks in a proton or neutron, for example.
structure Constituents of matter.
substructure More elementary ingredients of constituents of matter.
supergravity A supersymmetric theory that includes gravity.
superpartner (of a particle) The particle that supersymmetry pairs with another particle; if the original particle is a boson, the superpartner is a fermion, and vice versa.
superspace An abstract space that incorporates the familiar four dimensions as well as theoretical fermionic dimensions.
superstring theory The supersymmetric version of string theory without tachyons that includes fermions in addition to gravity