You are here: Home
Personal tools

Did you not find what you were looking for? Try the Advanced Search to refine your search.

Search results 480 items matching your search terms

Subscribe to an always-updated feed of these search terms

resonant detector
Detector for gravitational waves in which it is attempted to measure the influence of these waves on an oscillating test mass. More information about how such ...
reference frame
Already in special relativity, motion is relative, and whenever there is talk about a moving clock, one must give the additional information: Moving relative ...
redshift
The frequency of a simple light wave is directly related to its colour (cf. spectrum). For the lowest frequencies of visible light, that colour is red. If the ...
radio waves
Variety of electromagnetic radiation with frequencies of a few thousand to a few billion oscillations per second, corresponding to wave-lengths of a few ...
radio telescope
Any antenna used for radio astronomy, for instance to observepulsars or radio galaxies.
radio galaxy
One variety of the active galactic nuclei of young galaxies, whose central region radiates extremely great amounts of energy. Radio galaxies are distinguished ...
radio astronomy
Branch of astronomy dedicated to the detection and evaluation of radio waves from outer space. Such observations have led to the discoveries of radio galaxies, ...
radiation
In a general sense: Collective name for all phenomena in which energy is transported through space in the form of waves or particles. In a more restricted ...
radar
Abbreviation for "radio detection and ranging" - how to detect objects, and measure their distance, by means of sending out radio waves and detecting their ...
quasar
Class of active galactic nuclei. First noticed by radio astronomers as exceedingly bright radio sources that, in the night sky, did not appear more extended ...
quark
Elementary particle that is subject to the strong interaction. Quarks come in six species: up, down, strange, charme, bottom and top (with the last two ...
quantum theory
The framework for formulating the physical laws that govern the world at microscopic length-scales - the physics of the micro-world, for instance of atoms, ...
quantum physics
Quantum physics comprises all theories, models, experiments and applications connected that are based on the laws of quantum theory.
quantum particles
In classical physics, one can picture particles as little clumps of matter. At every time, such a clump has a definite location in space. In quantum theory, on ...
quantum mechanics
In a more general sense: synonymous with quantum theory. In a more restricted sense: The quantum theory of particles moving under the influence of forces - ...
quantum gravity
Theory based both on the effects, concepts and laws of quantum theory and on those of general relativity. To date, no complete such theory exists; the ...
quantum field theory, relativistic
Collective name for theories that are quantum theories based on the principles of special relativity. Typically, in relativistic quantum theory there exists ...
Quantum electrodynamics
Quantum theory of electromagnetic interactions. These interactions are described via the exchange of carrier particles called photons, for instance: when two ...
quantum effects
All effects and phenomena that follow from the fact that, deep down, our world obeys not the laws of classical physics, but those of quantum theory. Examples ...
Quantum chromodynamics
Quantum theory of the strong nuclear interactions between quarks (or compound particles made of quarks). These interactions are described via the exchange of ...
quantum cosmology
According to the big bang models, the energy density of the very early universe was extremely high, with the contents of the observable universe compressed ...
quantize
First of all, quantization is the process by which from a classical theory is constructed the corresponding quantum theory. For instance, if you quantize ...
Pythagoras' theorem
For a triangle in the plane (or in a more general flat space), two of whose sides form an angle of 90 degrees, the following holds: The lengths a and b of the ...
pulsar
Rotating neutron star from which regular pulses of radiation reach the Earth. Behind those pulses is the fact that the pulsar sends out narrowly focussed beams ...
PSR1913+16
A specific binary system consisting of two orbiting neutron stars, one of which is a pulsar from which we here on Earth receive regularly spaced radio pulses. ...
proton
Particle that carries positive electric charge and is comparatively massive; the atomic nuclei consist of protons and neutrons. Protons are not elementary ...
primordial
In cosmology: At, from, or relating to the beginning (or at least the early phases) of the universe. For example, the primordial abundances of the chemical ...
pressure
A measure for the strength of the resistance with which matter (for instance a gas) resists attempts to decrease the volume it occupies.
potential energy
When an object is being acted upon by a force like the electric or gravitational force, then it can be assigned an energy that depends only upon its location ...
post-Newtonian formalism
For situations in which gravity is very weak, general relativity and Newton's theory of gravity lead to very similar predictions for the motion of bodies and ...