synchrotron radiation
Electromagnetic radiation produced when electrically charged particles (for instance, electrons) are made to follow a curved trajectory in a particle accelerator, or when these particles undergo comparable accelerations in nature. Due to effects that can ...
symmetry
A situation has a symmetry if certain changes make no difference. For instance: a mirror-symmetric image that you view in a mirror looks the same. A perfect sphere looks the same, even if it is rotated around an arbitrary axis through its centre point ...
surface
Geometric space with two dimensions. Examples include the plane or the surface of a sphere. ...
surface gravity
The acceleration due to gravity which is experienced by an object resting on the surface of some solid body is called the body's surface gravity (as most of the solid bodies in question are shaped by gravity, the value for the surface gravity ...
supersymmetry
Abstract symmetry that some of the models of particle physics satisfy: in such models, for every species of particles, there is a partner species with the same mass. If the particles are matter particles (fermions), then the partner particles are force ...
superstring theory
Synonym: supersymmetric string theory. String theory that satisfies the requirements of an abstract symmetry called superymmetry. All models of string theory that are realistic candidates for a theory of quantum gravity, are superstring ...
supernova
Highly energetic explosion that ends the life of stars with more than about ten solar masses. In this explosion, the outer layers of the stars are ejected into space, while the core regions collapse to form a neutron star or even a black ...
supermassive black holes
are black holes with masses of more than a million solar masses. As far as we know, such holes can be found in the central regions of almost all galaxies. Central black holes are the energy source for radio galaxies and other active galactic nuclei. Basic ...
