Light-second
Units of distance: A light-year is the distance a light signal travels during one year of flight-time, a light-second the distance it travels in a second. The following table translates these units into the more familiar kilometres or seconds: 1 ...
light elements
According to the big bang models, the early universe underwent a brief period of primordial nucleosynthesis between a few seconds and a few minutes cosmic time, during which nuclei of light elements such as heavy hydrogen, helium and lithium formed. A ...
light-cone
In special as well as in general relativity, the speed of light sets the upper limit for the transmission of influences and signals. Thus, studying the propagation of light, one can find out for an event A which other events can influence A, which can be ...
length contraction
Effect of special relativity theory: An observer (more precisely: an inertial observer) measures a shorter length for a moving object than for an identical copy of that object resting beside him (here, length refers to extension in the direction ...
lead
Chemical element with the symbol Pb; each lead nucleus contains 82 protons. Lead nuclei, stripped of their electrons, are among the types of heavy ions which are brought into collision in particle accelerators such as the Relativistic Heavy Ion Collider in ...
laser
Abbreviation for "Light Amplification by Stimulated Emission of Radiation". Technique for the production of very concentrated, strong light with a fixed frequency, which propagates as a very simple electromagnetic wave in which wave crests and ...
