Large Hadron Collider
The Large Hadron Collider is a particle accelerator in the research centre CERN. From the point of view of relativity theory, it has several points of interest: First of all, it accelerates protons to higher energies than ever, allowing new tests of the ...
Lamb shift
Typically, electromagnetic radiation is emitted by atoms only at very specific frequencies that depend on the type of atom. For a number of these characteristic frequencies, the relativistic quantum theory of electromagnetism (called quantum electrodynamics) ...
Klein-Gordon equation
Equation regulating the behaviour of relativistic quantum particles with spin 0.
kinetic energy
A type of energy that has to be ascribed to an object simply because that object moves relative to the reference frame. In classical, pre-Einstein physics, the amount of energy is given by one half, times an object's mass, times the square of its ...
kilogram
In the international system of units (SI), the unit of mass; until May 2019 defined by a reference mass that is kept in Paris, France. From then on by definition of the Planck constant and of the Avogadro number that has an exact experimental value used for ...
