a type of WIMPs having masses about 10−10 of an electron mass
Big Bang
a gigantic explosion that threw out matter a few billion years ago
black holes
objects having such large gravitational fields that things can fall in, but nothing, not even light, can escape
word used to describe systems, the outcomes of which are extremely sensitive to initial conditions
an emerging field devoted to the study of complex systems
cosmic microwave background radiation (CMBR)
the spectrum of microwave radiation of cosmic origin
cosmological constant
a theoretical construct intimately related to the expansion and closure of the universe
cosmological red shift
the photon wavelength is stretched in transit from the source to the observer because of the expansion of space itself
the study of the character and evolution of the universe
critical density
the density of matter needed to just halt universal expansion
critical temperature
the temperature at which and below which a material becomes a superconductor
dark matter
indirectly observed non-luminous matter
electroweak epoch
the stage before 10−11 back to 10−34 after the Big Bang
escape velocity
takeoff velocity when kinetic energy just cancels gravitational potential energy
event horizon
the distance from the object at which the escape velocity is exactly the speed of light
flat (zero curvature) universe
a universe that is infinite but not curved
general relativity
Einstein's theory that describes all types of relative motion including accelerated motion and the effects of gravity
gravitational waves
mass-created distortions in space that propagate at the speed of light and are predicted by general relativity
GUT epoch
the time period from 10−43 to 10−34 after the Big Bang, when Grand Unification Theory, in which all forces except gravity are identical, governed the universe
Hubble constant
a central concept in cosmology whose value is determined by taking the slope of a graph of velocity versus distance, obtained from red shift measurements
inflationary scenario
the rapid expansion of the universe by an incredible factor of 10−50 for the brief time from 10−35 to about 10−32s
massive compact halo objects; microlensing objects of huge mass
a process in which light from a distant star is focused and the star appears to brighten in a characteristic manner, when a small body—smaller than about 1/1,000 the mass of the sun—passes between us and the star
negatively curved
an open universe that expands forever
a type of WIMPs having masses several orders of magnitude greater than nucleon masses
neutrino oscillations
a process in which any type of neutrino could change spontaneously into any other
neutron stars
literally a star composed of neutrons
positively curved
a universe that is closed and eventually contracts
Quantum gravity
the theory that deals with particle exchange of gravitons as the mechanism for the force
the moderately distant galaxies that emit as much or more energy than a normal galaxy
Schwarzschild radius
the radius of the event horizon
spontaneous symmetry breaking
the transition from GUT to electroweak where the forces were no longer unified
materials with resistivity of zero
hypothetical unified force in TOE epoch
Superstring theory
a theory to unify gravity with the other three forces, in which the fundamental particles are considered to act like one-dimensional vibrating strings
thought experiment
mental analysis of certain carefully and clearly defined situations to develop an idea
TOE epoch
before 10−43 after the Big Bang
weakly interacting massive particles; chargeless leptons (non-baryonic matter) interacting negligibly with normal matter