Index of physics articles (L)

This is an index page for physics articles beginning with the letter L. It is designed to help users navigate Wikipedia's coverage of physics-related topics. Below is a list of physics concepts, laws, scientists, experiments, and related fields, ordered alphabetically, starting with the letter "L".

• Laboratory frame of reference: A frame of reference fixed with respect to the laboratory.

• Ladder operators: Operators that raise or lower the eigenvalue of another operator. Commonly used in quantum mechanics, particularly for the quantum harmonic oscillator and angular momentum.

• Lagrange point: A location in space where the gravitational forces of two large bodies cancel each other, allowing a smaller object to remain in a relatively stable position.

• Lagrangian mechanics: A formulation of classical mechanics based on the Lagrangian, a function of the generalized coordinates and their time derivatives.

• Lagrangian: A function that summarizes the dynamics of a physical system. Often defined as the difference between the kinetic and potential energies.

• Lambda-CDM model: The standard model of Big Bang cosmology, incorporating a cosmological constant (Lambda) associated with dark energy and cold dark matter (CDM).

• Laminar flow: A type of fluid flow in which the fluid moves in smooth, parallel layers.

• Landau damping: A phenomenon where waves in plasma are damped due to interaction with particles moving at similar velocities.

• Landé g-factor: A factor relating the magnetic moment of an atom to its total angular momentum.

• Langevin equation: A stochastic differential equation describing the motion of a particle subject to random forces, often used to model Brownian motion.

• Laplace's equation: A second-order partial differential equation widely used in physics, especially in electrostatics, gravity, and fluid dynamics.

• Larmor frequency: The frequency at which the magnetic moment of an electron precesses in a magnetic field.

• Laser: A device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation.

• Latent heat: The heat required to change the state of a substance (e.g., solid to liquid) without changing its temperature.

• Law of conservation of angular momentum: A physical law stating that the total angular momentum of a closed system remains constant if no external torque acts upon it.

• Law of conservation of energy: A fundamental principle of physics stating that the total energy of an isolated system remains constant; energy can be transformed from one form to another, but cannot be created or destroyed.

• Law of conservation of mass: A principle stating that mass is neither created nor destroyed in ordinary chemical reactions and physical transformations. This is an approximation that holds well at non-relativistic speeds.

• Law of cooling: Newton's law of cooling, stating that the rate of heat loss of a body is proportional to the temperature difference between the body and its surroundings.

• Law of gravitation: Newton's law of universal gravitation, stating that every particle attracts every other particle in the universe with a force proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

• Laws of motion: Newton's three laws of motion, describing the relationship between a body and the forces acting upon it.

• Lepton: A fundamental particle that does not experience strong nuclear forces. Includes electrons, muons, tau particles, and their associated neutrinos.

• Liénard-Wiechert potential: Relativistic electromagnetic potentials for a point charge in arbitrary motion.

• Light: Electromagnetic radiation within a certain portion of the electromagnetic spectrum. Usually refers to visible light.

• Light cone: A representation of the possible paths of light rays emanating from or converging on a point in spacetime.

• Light-year: A unit of distance equal to the distance that light travels in one year.

• Linear accelerator: A type of particle accelerator in which particles are accelerated along a straight line.

• Linear algebra: A branch of mathematics concerned with vector spaces, linear equations, and linear transformations. Essential for many areas of physics.

• Linear momentum: A measure of the mass in motion; defined as the product of mass and velocity.

• Liquid: A state of matter that has a definite volume but no fixed shape.

• Liquid crystal: A state of matter that has properties between those of a conventional liquid and those of a solid crystal.

• Lorentz force: The force exerted on a charged particle moving in an electromagnetic field.

• Lorentz transformation: A transformation relating the spacetime coordinates of two observers moving at constant relative velocity, consistent with the postulates of special relativity.

• Luminosity: The total amount of energy emitted by an object per unit time.

• Lyman series: A series of spectral lines of hydrogen atoms in the ultraviolet region, resulting from electron transitions to the lowest energy level (n=1).