Science

Linus Pauling was an American chemist and peace activist whose research explained chemical bonding and protein structure and earned him two unshared Nobel Prizes.

The Lorentz force describes how electric and magnetic fields exert force on an electrically charged particle, governing its acceleration and deflection.

A Lorentz transformation relates spacetime coordinates while preserving the spacetime interval, providing the mathematical foundation for relativistic changes of reference frame.

Louis Pasteur was a French chemist and microbiologist whose research transformed understanding of fermentation, infectious disease, and vaccination.

Lymphoma is a diverse group of cancers arising from lymphocytes, with subtypes that differ in biology, clinical course, and treatment.

Macroscopic quantum coherence is the persistence of quantum phase relationships across many-particle systems or between distinct collective states.

Macroscopic quantum tunneling is the passage of a collective physical variable through an energy barrier that classical dynamics would prevent it from crossing.

A magnetic field describes magnetic forces on moving charges and magnetic moments, arising from electric currents, changing electric fields, and magnetized matter.

Magnetic flux quantization is the restriction of superconducting fluxoid—and, under suitable conditions, magnetic flux—to discrete multiples of h/2e.

The magnetic flux quantum, h/(2e), is the fundamental unit of fluxoid quantization in conventional superconductors.

Magnetic susceptibility quantifies a material’s magnetization response to a magnetic field, revealing its magnetic behavior and microscopic interactions.

Magnetization is magnetic dipole moment per unit volume, describing the magnitude and direction of a material’s magnetic state.

Maize is a cereal crop domesticated in Mexico and cultivated worldwide for food, animal feed, and industrial products.

Marie Curie was a Polish-born French physicist and chemist who discovered polonium and radium and received Nobel Prizes in two sciences.

Mass is a physical quantity that measures inertia, participates in gravitation, and corresponds to a system’s rest energy.

Mass number is the total number of protons and neutrons in an atomic nucleus, distinguishing isotopes without measuring their actual mass.

Mass spectrometry identifies and quantifies substances by measuring the mass-to-charge ratios and abundances of gas-phase ions.

Mass–energy equivalence relates a system’s invariant mass to its rest energy through Einstein’s equation E₀ = mc².

Max Planck was a German theoretical physicist whose work on thermal radiation introduced energy quanta and helped establish quantum theory.

Maxwell’s equations describe how electric and magnetic fields arise, interact, and propagate, providing the foundation of classical electromagnetism.

The measurement problem concerns how quantum theory’s continuous evolution and superpositions relate to definite measurement outcomes and their probabilities.

Measurement uncertainty quantifies the dispersion of values reasonably attributed to a measured quantity, using the information available about the measurement.

Meiosis is a specialized form of cell division that halves chromosome sets and reshuffles genetic information during sexual reproduction.

The Meissner effect is the expulsion of magnetic fields from a superconductor’s bulk in its equilibrium low-field state, distinguishing superconductivity from perfect conductivity.

A meson is an integer-spin hadron, conventionally described as a bound state of a quark and an antiquark.

Messenger RNA carries genetic information to ribosomes, where its sequence directs protein synthesis.

A MOSFET is an insulated-gate transistor that controls semiconductor conduction through an electric field, enabling electronic switching, amplification, and integrated circuits.

Methane is the simplest hydrocarbon, a major component of natural gas, and a greenhouse gas produced by biological and geological processes.

The metre is the SI base unit of length, defined through the exact speed of light in vacuum and the duration of the second.

The Metre Convention is the 1875 treaty establishing permanent international cooperation on measurement standards and the institutions that oversee the International System of Units.

Metrological traceability links a measurement result to a specified reference through a documented, unbroken calibration chain with evaluated uncertainties.

Metrology is the science of measurement, encompassing units, standards, calibration, uncertainty, and the comparability of measurement results.

Microbiology studies microorganisms and viruses, examining their structure, functions, diversity, interactions, and roles in health, industry, and the environment.

A microorganism is a microscopic organism belonging to diverse groups that sustain ecosystems, interact with hosts, and support industrial and scientific processes.

An instrument that reveals structures too small for unaided vision by forming images with light, electron beams, or scanning probes.

A microtubule is a hollow tubulin polymer that organizes cells, supports intracellular transport, enables chromosome segregation, and forms the structural core of cilia and flagella.

Miller indices are integer labels that describe crystal-plane orientations and identify diffraction reflections relative to a chosen crystallographic basis.

A mitochondrion is a double-membrane organelle that produces ATP and participates in metabolism, cellular signaling, and programmed cell death.

Mitosis is eukaryotic nuclear division that separates duplicated chromosomes into two daughter nuclei, normally preserving chromosome number and genetic information.

A dynamic microtubule-based apparatus that aligns and separates duplicated chromosomes during mitosis.

Molality expresses the amount of a dissolved substance per kilogram of solvent, providing a mass-based measure of solution composition.

The mole is the SI unit of amount of substance, defined by an exact number of specified elementary entities.

Mole fraction is the amount of one constituent divided by the total amount of all constituents in a mixture.

Molecular biology studies the molecular mechanisms of life, particularly how genetic information is stored, expressed, regulated, and transmitted.

Molecular recognition is the selective association of molecules through complementary structures and noncovalent interactions.

A molecular sieve is a porous material that selectively admits, adsorbs, or transports molecules according to their dimensions and interactions with its pores.

Moment of inertia measures how mass is distributed about an axis and determines a body's response to rotational acceleration.

Momentum is a vector quantity describing motion, conserved in isolated systems and fundamental to classical, relativistic, and quantum physics.

A muon is an unstable elementary particle similar to the electron but about 207 times heavier, important in cosmic radiation, precision physics, and materials research.

A mutation is a lasting change in genetic material that can generate biological variation, alter cellular functions, and contribute to evolution or disease.

Natural gas is a methane-rich fossil fuel extracted from geological deposits and used for heating, electricity generation, and chemical production.

Natural selection is differential reproductive success associated with heritable variation, changing populations across generations and producing adaptations.

An electrically neutral elementary particle that interacts weakly with matter, occurs in three known flavors, and exhibits oscillations demonstrating nonzero neutrino masses.

Neutrino oscillation is the quantum-mechanical change of neutrino flavor during propagation, revealing that neutrinos mix and have nonzero mass differences.

An electrically neutral subatomic particle that forms atomic nuclei with protons and plays essential roles in nuclear reactions and materials research.

A neutron star is an exceptionally dense stellar remnant whose structure is governed by gravity, quantum physics, and nuclear interactions.

The newton (N) is the SI unit of force, equal to one kilogram metre per second squared.

Nicolaus Copernicus was a Renaissance astronomer whose mathematical model of a moving Earth transformed European astronomy.

Niels Bohr was a Danish physicist whose work on atomic structure, quantum theory, and nuclear physics helped establish modern physics.

Nitrification is the microbial oxidation of ammonia or ammonium to nitrite and then nitrate, a major transformation in the nitrogen cycle.