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Luisa Neubauer
Luisa Neubauer (Luisa-Marie Neubauer), born 1996 in Hamburg, is a German climate activist co-organizing Fridays for Future Germany and lead plaintiff in Neubauer vs. Germany.
Luisa Torsi
Luisa Torsi is an Italian chemist, full professor of Chemistry at the University of Bari Aldo Moro since 2005, known for organic transistor biosensors and single-molecule detection.
Luitzen Egbertus Jan Brouwer
Luitzen Egbertus Jan Brouwer (1881–1966) was a Dutch mathematician and logician who founded modern topology, proving the fixed-point theorem, and founded intuitionism, which rejects the law of excluded middle.
Lukas J. Gooßen
Lukas J. Gooßen is a German organic chemist, born 1969 in Bielefeld, who holds the Evonik Chair of Organic Chemistry at Ruhr-Universität Bochum and is known for decarboxylative cross-coupling.
Lukas Novotny
Lukas Novotny (Lukáš Novotný), born 1966 in Czechoslovakia, is a Czech-born physicist, Professor of Photonics at ETH Zurich, known for near-field microscopy, optical antennas, and nanoparticle levitation.
Łukasiewicz logic
Łukasiewicz logic, also called Lukasiewicz fuzzy logic, is a many-valued logic introduced by Polish logician Jan Łukasiewicz in 1920, with truth values between true and false.
Łukasiewicz–Moisil algebra
A Łukasiewicz–Moisil algebra, also known as an LM algebra, is a bounded distributive lattice with nuance operations, introduced by Grigore Moisil in 1940 as an algebraic counterpart of Łukasiewicz's many-valued logic.
Lumen (unit)
The lumen (lm), commonly rated as ANSI lumens on projectors and lamps, is the SI unit of luminous flux, the rate at which a light source emits visible light weighted by the eye's sensitivity.
Luminance
Luminance is the photometric measure of luminous intensity per unit projected area in a specified direction, measured in candelas per square meter, and the quantity most closely matching perceived brightness.
Luminescence
Luminescence is the spontaneous emission of light from an excited substance not in thermal equilibrium with its surroundings, distinct from incandescence; Eilhard Wiedemann coined the term in 1888.
Luminescence dating
Luminescence dating, also called optical dating, is a family of geochronological methods that date when quartz or feldspar grains were last exposed to sunlight or heat.
Luminescence imaging
Luminescence imaging is a camera-based technique that maps light emitted by a sample, typically after electrical or optical excitation, to reveal defects and material properties.
Luminescence spectroscopy
Luminescence spectroscopy measures the light a substance emits after excitation, using the emitted spectrum to characterize electronic states, defects, and composition in materials and molecules.
Luminescence thermometry
Luminescence thermometry is a contactless technique that reads temperature from temperature-dependent features of light emitted by phosphors or nanoparticles, mapping temperatures in microfluidics, nanomedicine, and strong electromagnetic fields.
Luminex xMAP technology
Luminex xMAP technology, short for Multi-Analyte Profiling, is a bead-based multiplexing platform developed by Luminex Corporation that measures many analytes simultaneously in a single sample.
Luminiferous aether
The luminiferous aether, also spelled ether, was the hypothetical medium in which light was thought to travel as waves, abandoned after Einstein's 1905 relativity made it undetectable.
Luminosity
Luminosity is the total energy a star emits per second at all wavelengths, an intrinsic property distinct from apparent brightness; for main-sequence stars it rises steeply with mass.
Luminosity distance
Luminosity distance is the distance assigned to an astronomical object by comparing its observed flux with its intrinsic luminosity; Type Ia supernovae and gravitational-wave standard sirens measure it to probe cosmic expansion.
Luminosity measurement in particle physics
Luminosity measurement in particle physics is the set of techniques by which collider experiments determine how many collisions occurred, enabling conversion of event rates into cross sections.
Luminous blue variable
A luminous blue variable, also called an S Doradus variable, is a massive evolved star that shows large, irregular changes in brightness, with Eta Carinae a famous member.
Luminous efficacy
Luminous efficacy is a measure of how well a light source produces visible light, in lumens per watt; a traditional 60 W incandescent lamp achieves about 14 lm/W.
Luminous fast blue optical transient
A luminous fast blue optical transient is a rare cosmic explosion that rises and fades within days, 10 to 50 times brighter than a typical supernova.
Luminous flux
Luminous flux is the measure of the total light a source emits in all directions, weighted by human eye sensitivity and measured in lumens, central to lighting design.
Luminous infrared galaxy
A luminous infrared galaxy (LIRG) is a galaxy radiating more than 10^11 solar luminosities in the infrared, powered by dust heated by starbursts or active black holes.
Luminous intensity
Luminous intensity is a measure of the visible light a source emits in a particular direction, measured in candela, the SI base unit weighted by human-eye sensitivity.
Luminous red nova
A luminous red nova, or red nova, is a stellar outburst from two merging stars, redder and dimmer than a supernova but more energetic than a classical nova.
Luna Leopold
Luna Leopold (1915–2006) was an American hydrologist and geomorphologist, son of Aldo Leopold, who led the USGS Water Resources Division, taught at Berkeley, and turned river science quantitative.
Lunar and Planetary Institute
The Lunar and Planetary Institute (LPI) is a research institute in Houston, Texas, founded in 1968 to study Apollo lunar samples and now covering all planetary science.
Lunar calendar
A lunar calendar is one whose months follow the Moon's phase cycle, so a purely lunar year of 354 days drifts through the seasons in about 33 years.
Lunar distance
Lunar distance, also called Earth-Moon distance, is the separation between Earth and the Moon, averaging about 384,400 km and ranging from roughly 356,500 to 406,700 km.