states (of matter)
Depending on parameters like temperature or pressure, matter can exist in different states with greatly varying physical properties. The most important states of matter are the solid, liquid, gaseous and plasma states (the latter three forms of matter are ...
star
A cosmic gas ball that is massive enough for pressure and temperatur in its core to reach values where self-sustained nuclear fusion reactions set in. The energy set free in these reactions makes stars into very bright sources of light and other forms of ...
standard model of elementary particle physics
The current state of the art for describing the basic properties of matter and forces. The standard model theories are based on special relativity and quantum theory and they describe the behaviour of elementary matter particles such as electrons, neutrinos ...
standard acceleration
The acceleration imparted by the earth's gravitation to a body located on the earth's surface: If you raise such a body up a bit and let it fall, it will accelerate 9.81 metres per second squared, in other words: in every second, its speed will increase by ...
spin
Fundamental quantum property of elementary as well as of compound particles. For elementary particles, the spin determines whether the particle is a matter particle (half-integer spin such as 1/2, 3/2, 5/2 etc.) or a force particle (integer spin such as 0, 1, ...
spin network
In loop quantum gravity (one of the candidates for a theory of quantum gravity), the underlying microscopic structure of space is a spin network - a graph consisting of lines and nodes where each line is assigned a label consisting of a half-integer number. ...
sphere
A spherical surface is a simple example for a curved surface. It is easily pictured as a surface embedded in three-dimensional space: a spherical surface is the set of all points at a certain fixed distance from a given point (the point being the centre of ...
