Glossary – M


M-theory (physics): a physical theory that extends string theory into HD branes, postulating 11-dimensional spacetime.

Maat: the ancient Egyptian holistic concept of universal harmony. Maat’s polar opposite was Isfet: lies, chaos, and violence.

macaque: an Old World monkey of 22 species.

Macaronesia: 4 archipelagos in the North Atlantic Ocean off the coast of Europe and northwest Africa.

macaw: a long-tailed New World parrot of 18 species, often colorful.

MacDonald’s (1940–): American fast-food restaurant franchise company, founded by brothers Richard & Maurice MacDonald, and expanded as a franchise operation by Ray Kroc.

mace: a spice made from the aril of an evergreen tree in the Myristica genus, particularly Myristica fragrans.

Macedonia: an ancient kingdom on the northern periphery of Classical Greece which became the dominant state of Hellenistic Greece in the 4th century BCE.

macerate: to soften by wetting or chewing.

Mack Trucks (1907–): American truck maker.

macrobe: non-microbial life; any organism not requiring a microscope to be seen. Contrast microbe.

macroeconomics: the study of regional or national economic dynamics. Compare microeconomics. See political economy.

macrocephaly: an abnormally large head, only sometimes pathological.

macroevolution: origin of new species and evolutionary trends among related species. Contrast microevolution.

macrofungi: macroscopic fungi.

Macromedia (1992–2005) : an American graphics, multimedia, and web development software company; bought by Adobe Systems in 2005.

macromolecule: a large compound molecule, commonly created by polymerization of smaller subunits into polymer chains or 3D shapes. Nucleic acids, proteins, carbohydrates, and lipids are macromolecules.

Macronema transversum: a caddis fly with aquatic larvae that create elaborate protective cases.

macrophage (derived from the Greek for “large eater”): a type of phagocyte employed in vertebrate immune system defense.

macropod: a marsupial in the Macropodidae family, native to Australia, New Guinea, and nearby islands. Macropods include kangaroos, wallabies, and several others. Macropods have large, strong hind legs and powerfully muscled tails.

macroscopic: visible to the human eye. Contrast microscopic.

macrophage (derived from the Greek for “large eater”): a type of phagocyte employed in vertebrate immune system defense.

macrosmatic: having a highly developed sense of smell.

macrosociology: the study of societies. Compare microsociology.

macula (aka macula lutea): a yellow, oval-shaped spot near the center of the retina of the human eye with the fovea at its center.

mad cow disease (aka bovine spongiform encephalopathy): a fatal disease in cattle that turns the brain and spinal cord into spongy mush. The human variant of mad cow disease is called Creutzfeldt–Jakob disease.

Madagascar: a large island in the Indian Ocean off the coast of east Africa.

Madeira: an island in the north Atlantic Ocean, southwest of Portugal.

mafic: silicate mineral rich in in magnesium and iron. Basalt is a mafic rock. Mafic is a portmanteau of “magnesium” and “ferric” (referring to iron). Mafic rocks are 45–55% silica. Contrast felsic.

Magellanic Clouds: irregular dwarf galaxies orbiting the Milky Way.

Maghreb (previously known as Barbary Coast): a region of western north Africa comprising the Arab countries of Mauritania, Morocco, Algeria, Tunisia, and Libya. The Maghreb was originally inhabited by the Berbers.

magic number (nuclear physics): the number of nucleons (either protons or neutrons, separately) forming a complete nuclear shell for an element. The most common magic numbers are 2 (helium), 8 (oxygen), 20 (calcium), 28 (nickel), 50 (tin), 82 (lead), and 126 (for neutrons). The term came from Eugene Wigner in the mid-1940s.

magma: molten rock made underground. Igneous rocks come from cooled magma.

Magna Carta (Latin for great charter) (1215): a negotiated charter between King John I of England and his barony, who were at the point of revolt–and did so the next year in the 1st Baron’s War. The myth of the Magna Carta as a declaration of inalienable civil rights grew from later misinterpretation.

magnesium (Mg): the element with atomic number 12; an alkaline metal. Magnesium is the 4th most common element in the Earth, behind iron, oxygen, and silicon. Most magnesium is in the mantle.

magnet: a metal, such as iron, that sports an external magnetic field.

magnetic dipole moment: the potential exertion force of magnetism upon a particle.

magnetic moment (aka local moment): the torque a magnet will experience in an external magnetic field.

magnetic resonance imaging (MRI): a medical imaging technique used in radiology to form pictures of anatomy and bodily physiological processes.

magnetic reconnection: in conductive plasmas, rearrangement of magnetic topography and conversion of magnetic energy to heat, kinetic energy, and particle acceleration.

magnetism: a class of physical phenomena where atoms or molecules react from the influence of a magnetic field, which causes attraction or repulsion to nearby matter that is magnetically charged. Magnetism is a facet of electromagnetism. See ferromagnetism, antiferromagnetism.

magnetoencephalography: a technique using sensitive magnetometers to record magnetic fields produced by electrical currents in the brain, thereby allowing mapping electromagnetic brain activity.

magnetoreception: sensory reception of the Earth’s magnetic fields by biochemical means.

magnetosphere: the area of astrological space where charged particles are controlled by a heavenly body’s magnetic field. The Earth’s magnetosphere is an outer layer of the ionosphere.

Magnetospirillum: a genus of bacteria sensitive to magnetic fields. Magnetospirilla live in sediments and shallow fresh water.

magnon: a collective excitation of spin waves with magnetic effect.

magpie: a long-tailed corvid in the genus Pica.

mahasamādhi: intentionally leaving the body to die.

maintenance diet: the caloric intake needed to maintain present weight.

maize: See corn (an obvious American bias here).

major histocompatibility complex (MHC) (genetics): a group of vertebrate genes that code for cell-surface glycoproteins (MHC molecules) which are part of the immune system.

major histocompatibility complex molecule (molecular biology) (MHC molecule): a cell surface glycoprotein that consciously identifies a cell as native or not (biologically compatible or foreign).

major scale (music): a musical scale comprising 7 notes in an octave (diatonic) with only the 2nd and 7th notes as dissonant. Compare minor scale.

Majorana equation: a physics wave function using only real numbers. Most subatomic particles are defined by the Dirac equation, which necessitates complex numbers, with wave functions that result in complex conjugates. The Majorana equation characterizes Majorana fermions.

Majorana fermion: a fermion that is massless and chargeless, named after Ettore Majorana. Compare Dirac fermion, Weyl fermion.

malaria: a mosquito-borne infectious animal disease caused by Plasmodium falciparum, a parasitic protozoan.

malathion (C10H19O6PS2) (aka carbophos (Russia), maldison (Australia and New Zealnd), mercaptothion (south Africa)): an organophosphate insecticide that disrupts the nervous system.

Malay Archipelago: the archipelago between mainland Indochina and Australia, comprising over 25,000 islands.

mallard: a dabbing duck native to the temperate and subtropical Americas, Eurasia, and North Africa, and has been introduced elsewhere. Dabbing ducks are a subfamily (Anatinae) of the family Anatidae, which includes ducks, geese, and swans. Drakes have a glossy green head, and gray on their wings and bellies, whereas the hens have mainly brown-speckled plumage.

malleus (aka hammer): the hammer-shaped ossicle that rattles the incus.

mallow: an herbaceous plant in the Malva genus, with 25–30 species, widespread through Africa, Europe, and Asia, in tropical to temperate biomes.

maltose (C12H12O11; aka maltobiose or malt sugar): a disaccharide formed from 2 bonded units of glucose, formed via a condensation reaction.

malware: software intended to damage other computer software or take control of its operations.

mamavirus: a variant strain of the mimivirus.

mamba (Dendroaspis): a legendary, venomous, diurnal, African snake. Most mamba are arboreal, but the black mamba is terrestrial.

mammal: a class of air-breathing vertebrate animals, characterized by endothermy, hair, and females with mammary glands.

manakin: a 60-species clade of small passerines in the American tropics.

manatee: a large marine mammal in the same order (Sirenia) as dugongs.

Mānava-Dharmaśāstra (aka Manusmriti, Manu Smriti, Laws of Manu) (~200 BCE): an influential Hindu text on ethical governance.

Mandelbrot set: a 2D graphic representation from a formula for producing a fractal via construing each point on a plane by counting the number of times a complex number can be squared and added to itself before exceeding a set limit.

mandible: jawbone (the lower jaw in mammals).

mandrake: a plant in the genus Mandragora that produces powerful alkaloids which affect the nervous system, such as atropine and scopolamine. { Spokes 2 }

mandrake: a perennial in the Mandragora genus, native to southern Europe and the Levant. Mandrakes protect themselves with deliriants produced in the roots. Mandrake is mentioned in the Genesis 30:14–16 as a fertility drug. Yet its danger was well-known by that time. Ancient legend, carried for many centuries, has it that a mandrake root dug up screams and kills all who hear it.

“Shrieks like mandrakes’ torn out of the earth.” ~ William Shakespeare in Romeo and Juliet (1597)

Mandrake has long been associated with witchcraft and magic practices. { Spokes 4 }

mandrill (Mandrillus sphinx): an Old World monkey endemic to the western coastal region of equatorial Africa; closely related to the baboon.

mangabey: an Old World monkey of 3 genera. The name arose when mangabeys were mistakenly thought to be in a single genus. Whereas white-eyed mangabeys (Cercocebus) are closely related to mandrills, crested mangabeys (Lophocebus) are close kin to baboons. The highland mangabey (aka kipunji) is recently discovered – a single species in the genus Rungwecebus.

mangrove: various salt-tolerant (halophyte) trees that grow in coastal biomes in the tropics and subtropics.

mangrove snapper (Lutjanus griseus; aka gray snapper): a snapper species native to the western Atlantic Ocean.

mania: excessive excitement or enthusiasm.

manifest (adjective): a) capable or readily and instantly perceived by the senses; b) capable of being easily understood or recognized at once by the mind.

manifest destiny: the widely held belief by American settlers in the 19th century that they were destined to expand across North America.

manifestation: an outward, perceptible expression of Nature. Compare phenomenon.

manipularity: the ease with which an organism can manipulate its environment.

manipularity–intelligence hypothesis: a hypothesis by Ishi Nobu that the ease by which organisms can manipulate their environment is inversely related to acumen as a life-history variable.

Maniraptora: a clade of dinosaurs that begat birds and non-avian species.

manorialism: an agrarian estate feudal structure.

manspreading: a man spreading his legs while sitting on public transport so as to take up 2 seats.

manta ray (aka devil ray): a large ray in the Manta genus. Mantas are found near in warm marine waters. Many manta species migrate across open oceans singly or in groups, though at least 1 is resident and coastal.

mantis (plural: mantises or mantes): an order of tropical and temperate insects, with over 2,400 species in 430 genera. The closest relatives to mantes are cockroaches and termites.

mantis shrimp (aka stomatopod): a worldwide marine crustacean of around 400 species, typically solitary and aggressive. Mantis shrimp sport powerful claws which can spear, stun, or dismember prey. The ancient Assyrians called mantis shrimp “sea locusts.”

mantle: the layer of Earth above the core and below the crust.

mantle plume: the rising of hot rock from the core-mantle boundary through the mantle to become a diapir (intrusion) in the Earth’s crust.

mantra: a resonant vibration used to attain transcendence.

many-body problem: a set of equations that characterize a system comprising many interacting components. Attempting to solve a many-body problem is computationally intensive. Approximations are often relied upon.

“It would indeed be remarkable if Nature fortified herself against further advances in knowledge behind the analytical difficulties of the many-body problem.” ~ Max Born in 1960

many-body theory: a physics theory which models a system characterized by a plethora of interacting particles.

many-worlds interpretation (aka parallel universes): a fanciful extension of wave/particle duality (Schrödinger’s equation) which posits that quantum waveforms represent an infinity of actual parallel universes. First suggested by Erwin Schrödinger in 1952, then formally proposed by Hugh Everett III in 1956. The many-worlds interpretation discards Heisenberg’s uncertainty principle, which posits that figurative quantum waveforms collapse into actual quanta via observation; substituting an observer-free interpretation, in insisting that all the potentialities of quantum waveforms are actualized; whence many worlds.

Māori: the indigenous Polynesian people of New Zealand, who arrived in waves from the mid-13th century to the end of the century, then established their own unique culture.

marbled crayfish (aka marmokreb, Procambarus virginalis): a small (4–8 cm) freshwater crayfish, unique among decapods in being parthenogenetic. The marbled crayfish prefers warmer waters – cold waters kill. Unlike some other crayfish, marmokrebs do not burrow. Discovered in German pet stores in the late 1990s and let loose by pet owners, wild established populations are usually found in urban semi-natural water bodies.

Marbury v. Madison (1803): a landmark supreme court decision that established the principle of judicial review in the US, a power not clearly granted by the constitution.

margay (Leopardus wiedii): a spotted, nocturnal, arboreal cat, native to the Americas. Margays look much like ocelots.

marginalism: a school of economic thought emphasizing the incremental nature of economic activity.

Mariana Trench (aka Marianas Trench): a deep-ocean trench in the western Pacific Ocean, to the east of the Mariana Islands. With a maximum depth of ~11 km, the trench is 2,550 km long, averaging 69 km wide. The Mariana Trench forms where the Pacific tectonic plate subducts from the east beneath the Mariana plate to the west. Pressure at the bottom of the trench is over 1,000 times sea-level atmospheric pressure. Temperature is 1–4 ºC. Fish, crustaceans, and other animals live deep within the trench, which also hosts abundant microbial life.

marijuana (aka cannabis): a preparation of the cannabis plant. Marijuana is a popular psychoactive drug that induces a relaxed euphoria, and an increase in appetite, commonly called “the munchies.” Prolonged use diminishes intelligence and short-term memory.

marine iguana (aka sea iguana, saltwater iguana, Amblyrhynchus cristatus): an iguana endemic to the Galápagos Islands with the unique ability to forage in the sea, feeding almost exclusively on algae residing on rocks.

marine snow: see dissolved organic matter.

mariposa lily (Calochortus apiculatus): a lily with open wedge-shaped petals; endemic to California.

marjoram (Origanum majorana): a cold-sensitive perennial herb in the mint family, native to Cyprus and southern Turkey.

Mariana Trench (aka Marianas Trench): a deep-ocean trench in the western Pacific Ocean, to the east of the Mariana Islands. With a maximum depth of ~11 km, the trench is 2,550 km long, averaging 69 km wide. The Mariana Trench forms where the Pacific tectonic plate subducts from the east beneath the Mariana plate to the west. Pressure at the bottom of the trench is over 1,000 times sea-level atmospheric pressure. Temperature is 1–4 ºC. Fish, crustaceans, and other animals live deep within the trench, which also hosts abundant microbial life.

Mark I (aka Automatic Sequence Controlled Calculator (ASCC)): an electromechanical computer proposed by Howard Aiken. Work began in 1937. IBM funded the effort from 1939. The calculator was completed in February 1944, and officially retired in 1959.

market: an aggregation of buyers and sellers for a certain range of products and/or services.

market economy: an anarchic economy, reliant upon market transactions. Contrast command economy.

Markov chain: a stochastic process with the Markov property of memorylessness: randomness, as shown by a state status being relative only to the previous state, with no regard to what had gone on before.

Markov property: the memoryless property of a stochastic process, termed after Russian mathematician Andrey Markov. A Markov process depends only upon the present state, with no reference to antecedents.

marmoset (aka zari): a small New World monkey of 22 species in 4 genera.

marmot: a large, herbivorous squirrel found in mountainous regions in the northern hemisphere, of 15 species in the Marmota genus. Marmots typically live in burrows and hibernate there through the winter.

Mars: the 4th planet from the Sun, with 2 small, irregularly shaped moons.

marsh: a wetland that is dominated by herbaceous rather than woody plants.

Marshall Plan (officially the European Recovery Program) (1947–1950): an American aid program to western European nations after World War 2; named after Secretary of State George Marshall, as he had bipartisan political admiration for his soldiering during the War.

marsupial: a clade of mammals, characterized by giving birth to relatively undeveloped live young. An infant marsupial (joey) develops within its mother’s pouch.

marsupial mouse (aka pouched mouse, antechinus shrew): a small, shrew-like, carnivorous marsupial in the genus Antechinus, indigenous to Australia.

marula tree (Sclerocarya birrea): a medium-sized fruiting tree indigenous to the woodlands of South Africa.

Marxism: a worldview and method of societal analysis focused on the dynamics, especially the conflicts, of economic classes; conceived by Karl Marx.

mascon (mass concentration): a sizable gravity anomaly in a terrestrial body, often caused by compression from meteorite impacts.

masked hunter (Reduvius personatus): an assassin bug that lures its victims by attaching debris to itself and making itself a curiosity. Bed bugs are a favorite, though humans are tasty too. Its bite is painful.

mason bee: a bee so named for its practice of using mud or other masonry materials to build its nest.

mass (classical physics): a measure of inertia. Contrast weight.

mass (quantum mechanics): the energy level at which an elemental quantum may make an observable appearance.

mass extinction: the indiscriminate extinction of many species during an extinction event. Contrast background extinction.

Massachusetts Institute of Technology (MIT) (1861–): a private research university in Cambridge, Massachusetts.

mast cell: a tissue-resident granulocyte that promotes inflammation and wound healing.

mast seeding: a stratagem of some trees to greatly vary seed production from year to year, to stress animal seed eaters and improve plant survival prospects.

mastodon (26.8 MYA–11 TYA): an elephant-like animal hunted to extinction by humans.

Matabele ant (Megaponera analis): a termite-eating ant.

matamata turtle: a freshwater turtle native to South America, primarily the Amazon and Orinoco basins. Matamata are carnivorous, feeding exclusively on fish and aquatic invertebrates. Matamata swallow prey whole, as their mouth is not built for chewing.

materials science: the discovery and design of new configurations of matter, especially solids.

materialism (psychology, economics): a worldview valuing material consumption and possessions. Contrast freedom.

mathematics: the systematic treatment of relations between symbolic entities.

matriarchy: a social organization where females are dominant. Contrast patriarchy.

matric potential: the adhesive intermolecular forces that water has for solid particles; in other words, water’s cling to things.

matriline: a female-dominated social group. Matrilines are formed by females staying with their natal group. Males typically emigrate to another group upon reaching sexual maturity. Most Old World monkeys are matriline.

Matryoshka doll: a set of hollow wooden dolls of decreasing size which can be placed one inside another.

matter (physics): something with mass, constructed of fermions. See energy.

matterism (aka (philosophical) materialism): the monistic belief that reality is made of matter. Matterism supposes that the mind is a figment of something substantial. Contrast energyism.

Mauryan Empire (India) (322–185 BCE): an empire centered in northwestern India, founded by Chandragupta Maurya. One of the largest and most populous (~55 million) empire of its time, and the 1st political unification of India.

mavirus: a virophage that relies upon and fouls the works of CroV, a giant marine virus. The name mavirus is a contraction of “maverick virus.”

māyā (Hinduism, Buddhism): misperception of reality by not considering it an illusion.

Maya: an ancient people inhabiting Mesoamerica (central America). The earliest Mayan villages and agriculture date to ~1500 BCE.

McDonnell Douglas (1967–): American aerospace manufacturer and war machine provider. The parent companies were Douglas Aircraft (founded 1921) and McDonnell Aircraft (founded 1939).

meadowlark: a group of New World grassland birds comprising 7 species. Meadowlarks are largely insectivorous. Male meadowlarks have a black or brown back, and extensively yellow or red underparts. Compare longclaw.

mean (statistics) (aka expected value): a measure of the central tendency of a probability distribution.

meaning: import, purport, signification, significance; in communication meaning means intent or signification.

measles: a highly contagious viral disease, as it may infect through the air, with symptoms developing 7–10 days after infection.

meat (food): solid food, especially animal tissue.

meat ant (aka gravel ant, Iridomyrmex purpureus): an ant native to Australia.

mechanics: the branch of physics concerned with the actions of forces on bodies, and with motion.

mechanical isolation (evolutionary biology): reproductive incompatibility between a species and its descendant.

mechanical solidarity: societal adhesion among people with similar lives, united via shared values and social bonds. Contrast organic solidarity. Compare gemeinshaft, gesellschaft.

median: the value in an ordered set in which an equal number of quantities are above and below. See mean.

Medicaid (US): a US national health insurance program for the poor.

Medicare: (US): a US national health insurance program for those 65 and older, and the disabled.

Medieval period: the Middle Ages. See Middle Ages.

meditation: a practice intended to achieve a transcendental state of consciousness. Yoga is intended as a physical form of meditation.

Mediterranean basin: the terrestrial region around the Mediterranean Sea that has a Mediterranean climate of mild, rainy winters and hot, dry summers.

Mediterranean Sea: the sea connected to the Atlantic Ocean and enclosed by the Mediterranean region of southern Europe and western Anatolia, north Africa, and the Levant.

medulla (aka medulla oblongata): the lower half of the brainstem.

meerkat (aka suricate, Suricata suricatta): a gregarious mongoose with a decided social hierarchy, endemic to south Africa.

megabat (aka fruit bat, Old World fruit bat): a herbivorous bat in the suborder Megachiroptera, native to tropical and subtropical Eurasia, Africa, and Oceania. Fruit bats are relatively large and do not navigate via echolocation, with some exceptions.

megabyte (MB): 220 (1,048,576) bytes (= 1,0242).

megafauna: large animals.

Megalomyrmex: a genus of ant that are social parasites of attine ants.

megaphyll: a leaf with multiple veins. Contrast microphyll.

megapode (aka incubator bird): a stocky, chickenish bird with a small head and large feet, living in wooded habitats; endemic to Australasia. Megapodes are mainly solitary birds.

Meiji era (aka Meiji period) (1868–1912): the period in Japan immediately following the end of the Tokugawa Shogunate (Edo Period). The emperor was restored preeminence while the country modernized economically in the wake of threat of foreign incursion, especially by the United States. Japan became the 1st industrialized Asian nation.

meiosis: the special cell division for sexual reproduction, producing germline gametes. Meiosis also refers to the cell division process for making spores. Compare mitosis.

meiotic drive: manipulation during meiosis by a chromosome to become part of a gamete.

Meissner effect: the complete expulsion of magnetic field lines from inside a superconductor as it transitions to a superconducting state. Named after its discoverer: Walther Meissner.

Meissner’s corpuscle: a mechanoreceptor sensitive to light touch. Compare Merkel cell.

Mekong River: a river flowing south from west-central China, through southeast Asia (Myanmar, Laos, Thailand, Cambodia, and Vietnam), before discharging into the South China.

Melanesia: a region of Oceania, extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji. Melanesia including the countries of Papua New Guinea, Solomon Islands, Vanuatu, and Fiji.

melanin: a group of pigments found in most organisms.

melanogenesis: the production of melanin.

meliponine (aka stingless bee): a eusocial bee of ~500 species in the tribe Meliponini, closely related to honeybees, bumblebees, carpenter bees, and orchid bees.

melatonin: a hormone found in microbes, plants, and animals. In animals, melatonin levels cyclically vary every day, affording entrainment of circadian rhythms.

melinjo (tree) (Gnetum gnemon): a tree native to Southeast Asia and western Pacific Ocean islands. Melinjo seeds, fruit, flowers, and leaves are used in Indonesian cuisine.

mellitene (C12H18, in the structural formula C6(CH3)6; aka hexamethylbenzene): an aromatic hydrocarbon derivative of benzene, composed of 6 methyl groups where carbon atoms have 6 bonds (not the usual 4).

melody: the tonal pattern of music. Compare rhythm.

melon (botany): the fleshy round fruit of plants (e.g., watermelon, muskmelon (including cantaloupes, and the smooth-skinned honeydew)).

melon (zoology): the round organ at the top front of a dolphin’s head, used for echolocation.

melyrid beetle: a tiny beetle (up to 1 cm) noted for its toxicity.

membrane (cytology): a lipid bilayer surrounding a cell, providing a barrier between the cell and the outside world.

memory: mental storage of past events; casually, memory refers to long-term memory.

memory conformity: the process of a person conforming to the socially acceptable version of an event. Under private conformity, the person is brainwashed to conviction. With public conformity, a person complies while still believing in the veracity of a divergent private recollection.

memory inflation: see imagination inflation.

menarche: the initiation of menstruation.

Mendelian inheritance: biological inheritance following laws proposed by Gregor Mendel.

meninges: the protective membranes that envelop the central nervous.

meningitis: acute inflammation of the meninges.

meningococcus (Neisseria meningitidis): the bacterium that causes meningitis.

meniscus: the characteristic curve in the upper surface of a liquid at the top of the surface of a narrow container. A meniscus is caused by surface tension of the confined liquid. Water has a convex meniscus, while mercury has a concave meniscus.

menopause: the transitional period in vertebrates of reproductive senescence some time before natural death; typically occurring in women between 45–55 years of age.

mental time travel: remembering previous activity patterns and anticipating and planning for future events.

mental ecology: (the study of) the interfaces of internal mental operations and interpersonal interactions.

mental model: an internal representation of contextual information.

mental set: the tendency to approach a new problem the same way as one previously encountered.

mentalizing (aka mind perception): inferring the mental state of another being, typically another person. Compare dementalizing.

mentation: mental activity.

menthol (C10H20O): a mint oil.

mentotype: the psychological constitution of an organism, including cognitive orientations and capacities, awareness loci, and worldview. Compare phenotype.

mercantilism: the economic theory and praxis dominant in Europe in the 16th–18th centuries, promoting governmental regulation of the economy so as to augment state power. Today’s vestige of mercantilism is called economic nationalism.

Merced clarkia (Clarkia lingulata): a rare evening primrose endemic to California; now endangered, owing to herbicide use.

Mercury: the planet closest to the Sun, and the smallest. A Mercury year is equivalent to 88 Earth days.

mercury (Hg): the element with atomic number 80. Mercury is the only metal that is liquid at room temperature and pressure. Mercury has a melting point of –38.83 ºC and a boiling point of 356.73 ºC, making it a metal with one of the narrowest ranges for its liquid state.

mercury poisoning (aka mercurialism, hydrargyria): poisoning by exposure to mercury, typically methylmercury.

meristem: plant tissue where growth occurs. Meristematic plant cells are analogous to animal stem cells.

Merkel cell: an oval tactile receptor cell found in the skin of vertebrates, associated with prolonged pressure and discrimination of texture and shape. Compare Meissner’s corpuscle.

meroplankton: organisms that are planktonic for only part of their lives.

Merovingian (~450–751): a Salian Frank dynasty.

mesenchyme: a type of tissue in the lymphatic and circulatory systems and connective tissue, including bone and cartilage.

mesh: a crystal lattice.

Mesoamerica: the geographic area extending from central Mexico to South America, with shared prehistoric cultural characteristics.

mesocarp: the middle layer of a pericarp, comprising the pulp of a fruit.

mesoglea: a non-living jelly, sandwiched between 2 thin (single cell) layers of epithelium, which functions as a hydrostatic skeleton.

mesohyl: the gelatinous matrix within a sponge that resembles connective tissue.

Mesolithic (20–5 tya): the final period of foraging in human cultures as the predominant lifestyle, before giving way to agriculture, between the Upper Paleolithic and Neolithic; 20–8 TYA in southwest Asia, 15–5 TYA in Europe.

mesomorph: a somatype of an athletic build. Compare ectomorph, endomorph.

meson: a hadronic subatomic particle comprising 1 quark and 1 antiquark.

mesophile: an organism suited to moderate temperature: 20–45 ºC.

mesopic vision: a combination of photopic and scotopic vision in crepuscular light.

Mesopotamia: an area of the Tigris–Euphrates river system, widely considered the Western cradle of civilization during the Bronze Age. Indigenous Sumerians, Assyrians, and Babylonians were there at the onset of written history 3100 BCE.

mesosphere: the layer of Earth’s atmosphere below the thermosphere and above the stratosphere. The mesosphere is 53–85 km above Earth’s surface.

mesotherm: an animal with internal means to raise body temperature, but not with the precision of maintaining thermal homeostasis like endotherms. See ectotherm, endotherm.

mesotocin (C43H66N12O12S2): a peptide hormone which regulates sociability in birds; functionally like oxytocin in humans.

Mesozoic (252–66 mya): the geological era – called the Age of Reptiles by Gideon Marshall – which includes the Triassic, Jurassic, and Cretaceous periods.

messenger RNA (mRNA): an RNA molecule with the physical blueprint for a protein product.

metabolic pathway: a series of chemical reactions within a cell, typically with an intended biological end product.

metabolic rate: the speed at which a metabolic pathway transpires.

metabolism: cellular chemical reactions which provide energy for vital processes. See anabolism, catabolism.

metabolite: a product of metabolism.

metacognition: knowing what one knows. See introspection.

metacommunication: a communication qualifier ; indirect cues as to how information is meant to be interpreted. Animals employ metacommunication to convey the intent of communications that follow a metacommunication. An adult male lion bows before a cub as an invitation to play; a gesture that has no other context.

metagenome: (the idea of) the combined genome of an organism, which includes both host and microbiome genomes.

metal: an element that readily conducts heat and electricity. 91 of the 118 elements are metals. Some elements have both metallic and nonmetallic phases. Compare metalloid, nonmetal.

metallicity (astronomy): the proportion of matter in a heavenly body other than hydrogen and helium.

metalloid (aka semimetal): a chemical element with properties of metals and nonmetals. There is no standard definition of a metalloid, but the term is common in chemistry.

metallurgy: the extraction of metals from their ores.

metamerism: a plant or animal with a body comprising a linear series of segments, similarly in structure. Earthworms and centipedes are metameric.

metamessage: an underlying meaning or subtext.

metamorphic (rock): a rock arising from transformation via heat and pressure. The original rock (protolith) may be igneous, sedimentary, or a previous incarnate metamorphic. Compare igneous and sedimentary. See basement.

metamorphism (geology): the recrystallization of a rock owing to heat, pressure, or chemically active fluids.

metamorphosis: conspicuous and relatively abrupt changes in phenotype during the life cycle of an animal, usually accompanied by a change in habitat and/or behavior. Some insects, mollusks, amphibians, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis. The 3 types of metamorphosis are ametabolous, hemimetabolous, and holometabolous.

metaphysics: philosophy concerned with first principles, including ontology and epistemology.

metaplasia: a reversible transformation of one differentiated cell type to another.

metapleural gland: an antibiotic secretory gland unique to ants, and basal in the evolution of ants. Ants groom the secretion onto their exoskeleton to prevent bacterial and fungal growth. Some ant species lack metapleural glands, particularly arboreal ants, who suffer less exposure to parasites than terrestrial ants. Most male ants do not have metapleural glands, instead benefiting from shared secretions from female ant workers. Slave-making ants do not have metapleural glands, but their slaves do. These ants have their slaves groom the slavemakers and their brood.

metamonada: a group of anaerobic flagellate protozoa, most of which live as gut flora symbionts.

metaphase: the stage of cell division where chromosomes migrate to opposite poles of a cell.

metapleural gland: an antibiotic secretory gland unique to ants, and basal in the evolution of ants. Ants groom the secretion onto their exoskeleton to prevent bacterial and fungal growth. Some ant species lack metapleural glands, especially arboreal ants, who suffer less exposure to parasites than terrestrial ants. Most male ants do not have metapleural glands, instead benefiting from shared secretions from female ant workers.

metastasis: change of position, state, or form; commonly used to indicate spread of a disease within a body.

metazoan (plural: metazoa, metazoans): a multicellular animal.

meteorite: a sizable rock from space that managed to smack a terrestrial body’s surface. A meteorite might be a comet or an asteroid.

methane (CH4): a flammable, explosive gas, which is colorless, odorless, and tasteless to humans. Methane forms in marshes and swamps, from decaying organic matter.

methanogen: anoxic archaea that produce methane as a metabolic by-product.

methanol (CH3OH): a simple alcohol; a polar liquid; a byproduct of anaerobic metabolism; a key substrate in the synthesis of organic molecules leading to life.

methanotroph (aka methanophile): a prokaryote that consumes methane.

method of exhaustion: an approximate mathematical method for finding the area of a shape by inscribing within it a sequence of polygons whose areas converge to the area of the containing shape.

methodicalness: the tendency to habitually proceed systematically.

methodology: a body of methods, procedures, working concepts, postulates, and rules employed by a discipline of study. Note that all disciplines are knowledge oriented.

methylmercury (CH3Hg+): an organometallic cation that is a bioaccumulative environmental toxicant.

metoposaur: an extinct family of amphibians that arose during the Triassic; a trematosaurian temnospondyl. Though no relation, metoposaurs somewhat resembled crocodiles.

methoxy: a methyl group bound to oxygen.

methyl group: an alkyl derived from methane (CH4).

methyl jasmonate (C13H20O3): a volatile compound that plants employ for defense.

methyl salicylate (C8H8O3): an ester produced by plants for bacterial defense.

methylation: an epigenetic mechanism that stifles or inactivates a gene by attaching methyl groups to nucleobases.

methylene (H2C; aka carbene, λ2-methane): a colorless gas that is the simplest carbene.

Mexica (aka Aztecs): an indigenous people of the Valley of Mexico, known as the rulers of the Aztec Empire.

Mexican tetra (aka blind cave fish, blind tetra, Astyanax mexicanus): a pinkish-white, freshwater fish, native to rivers in Texas and eastern Mexico, that grows to 12 cm.

Mexican yam: a yam native to Mexico that grows an aboveground caudex dome.

MHC: see major histocompatibility complex.

Micaria: a genus of ground spider found throughout much of the world except Central and South America.

Michelson-Morley experiment: the 1887 experiment by Albert Michelson and Edward Morley to demonstrate the existence of the cosmic aether. The experiment failed and is widely considered the most famous failed experiment in physics history.

microaerophile: a microbe that requires only modest amounts of oxygen to survive.

microbe: a microorganism, too tiny to be seen without a microscope; often a single-celled prokaryote. Microbes include archaea, bacteria, and fungi. Contrast macrobe.

microbial loop: recovery of otherwise lost organic energy by bacteria.

microbiome: the endosymbiotic, microbial community that comprises every eukaryotic organism, especially multicellular eukaryotes. Commensal prokaryotic inhabitants are essential to eukaryotic life.

microbiota: the microbes in a microbiome.

microeconomics: the study of the economic dynamics of households and businesses. Compare macroeconomics.

microevolution: changes within species. Contrast macroevolution.

microfibril (botany): a fine fibril consisting of glycoproteins and cellulose. Plant cell walls comprise microfibrils.

microglia: a glial cell type that guides neural development and maintains nerve synaptic connection.

micrometer (aka micron) (μm): 1 millionth of a meter (1×10–6).

microparasitism: parasitic behavior by a microbe.

microphyll: a leaf with a single, unbranched vein. Contrast megaphyll.

microprocessor: an integrated-circuit semiconductor chip that incorporates a computer’s central processing unit (CPU).

Microraptor: a genus of small, 4-winged bird-like dinosaurs.

microRNA (miRNA): a class of post-transcriptional regulators which bind to microRNA response elements (MREs), thereby decreasing the stability of protein-coding messenger RNAs (mRNA) or limiting their protein translation. The result is typically stifling or silencing gene expression. See RNAi.

microsaccade: a tiny, jerky, involuntary eye movement. Microsaccade amplitudes vary from 2 to 120 arcminutes. Compare saccade.

microscopic: visible to humans only by using a microscope. Contrast macroscopic.

microsociology: the study of social interactions. Compare macrosociology.

Microsoft (1975–): American software company founded by Paul Allen and Bill Gates. Being contracted by IBM to develop the OS for the IBM PC in 1980 put Microsoft in the catbird seat in the software industry; a monopolistic position that it ruthlessly strived to maintain. Microsoft makes the world’s most popular operating system (Windows) and general productivity software (Office).

microsporidium (plural: microsporidia): a unicellular spore-forming intracellular fungal parasite in the phylum Microspora.

microtubule: a rope-like macromolecule of protein; part of the cytoskeleton. Macrotubules are employed in cell structural maintenance, intracellular transport, forming the spindle during mitosis, and other cellular functions. Microtubules are comprised of tubulins.

microwave: a radio wave with a wavelength ranging between 1 meter and 1 millimeter; equivalently, between 300 MHz (0.3 GHz) and 300 GHz frequency.

midocean ridge: a marine mountain range formed by plate tectonics.

midbrain (aka mesencephalon): the portion of the vertebrate brain associated with vision, hearing, motor control, alertness, sleep/wake and temperature regulation.

Middle Ages (aka Medieval period) (ca. 467–1400): the period of European history between the 5th and 15th centuries, beginning with the collapse of the Roman Empire and the onset of the Dark Ages.

Middle East: a region of western Asia, albeit including Egypt.

midge: a common term for a species-diverse group of tiny flies.

migration: purposeful travel over long distance by an animal.

Migration Period (aka Völkerwanderung) (376–800): a period of intensified human migration in Europe.

Milankovitch cycle: a 1920 hypothesis by Milutin Milanković relating changes in sunlight, and thereby climate, to variations in Earth’s orbit about the Sun. Earth has an elliptical orbit, with eccentricities in that orbit, as well in its axial tilt and precession (rotational orientation). Milankovitch cycles are now used extensively to explain the timing of glacial-interglacial cycles in Earth’s evolution.

militarism: subordination of civil society to the military as a virtuous ideal.

milk: a fluid secreted by female mammary glands for nourishment of their young offspring; also used for a liquid resembling milk, including the juice of a coconut, the latex of a plant, or the fluid contents of an unripe grain kernel.

milk snake (Lampropeltis triangulum): a nonvenomous kingsnake found from southeastern Canada through much of the United States, down to northern South America.

milkfish: a large schooling marine fish of the Indian and Pacific oceans. Milkfish are important seafood in southeast Asia.

milkweed: an herbaceous perennial dicot of over 140 known species in the Asclepias genus, native to North America. Milkweeds are among the most complex flowers, comparable to orchids.

milkweed butterfly (subfamily Danainae): a brush-footed butterfly that lays its eggs on milkweeds, upon which their larvae feed. There are ~300 danaine butterfly species worldwide, found mostly in tropical Asia and Africa.

Milky Way: the spiral galaxy containing the solar system, formed 13.2 bya; 120,000 light-years in diameter, containing up 200–400 billion stars, and at least 640 billion planets.

millet: a small seed grass in different taxonomic grain groups (tribes).

millipede: a segmented wormy arthropod comprising over 20 segments with 2 pairs of jointed legs on most body segments, of 15,000–80,000 species, of which 12,000 have been described.

milt: the seminal fluid of fish, mollusks, and other water dwellers, who reproduce by spraying milt, which is loaded with sperm, onto roe (fish eggs).

mimesis: imitative behavior; typically, an animal defense.

mimetic desire: desire provoked by what someone else wants.

mimicry (biology): trait imitation by a species.

mimivirus: a giant virus in the Mimivirus genus that infects amoebae.

mind: an intangible organ for symbolic processing.

mind perception (aka mentalizing): inferring the mental state of another being, typically another person. See theory of mind.

mind pop: spontaneous involuntary recall of something from the past, commonly somehow related to what had the subject of recent conscious thought (even though the link may be obscure or subconsciously made).

mind-body: the mind and body as an integral life form.

mind-body problem: the unsolvable inquiry into the functional interface between the intangible mind and the physical body.

mind-brain: the mind and animal brain as an integrated unit for mentation.

mind-set: a fixed mental orientation.

mindfulness (aka mindfulness meditation): the practice of paying attention to the prattles of the mind, which has ignorantly been popularized as a form of meditation when it is nothing of the sort. Compare introspection, metacognition.

mineral: a solid homogeneous crystal.

mineralogy: the study of minerals.

Ming Dynasty (aka Empire of the Great Ming) (1368 – 1644): the ruling dynasty of China for 276 years, noted by historians as “one of the greatest eras of orderly government and social stability in human history.”

minnow: a small freshwater fish in the carp family.

Minoan (civilization) (~2800–1420 BCE): an Aegean Bronze Age civilization flourishing on the island of Crete until overrun by the Mycenaeans from mainland Greece.

mint (aka deadnettle, Lamiaceae, Labiatae): a family of predominantly perennial flowering plants with 13–18 species, many of which have aromatic parts. Mint family plants include many widely used culinary herbs, such as basil, lavender, marjoram, mint, oregano, rosemary, sage, savory, and thyme.

Miocene (23–5.3 mya): the 1st of 2 epochs in the Neogene period, divided into 6 ages with corresponding rock stages.

miracle fruit (aka miracle berry, sweet berry, Synsepalum dulcificum): a west African plant with a tangy berry that causes subsequently consumed sour foods to taste sweet.

miraculin: a glycoprotein extracted from miracle fruit that is a natural sugar substitute.

mirror neuron: a nerve cell in the premotor cortex that responds both to sensed movement externally and self-initiated.

mirror test: the dumb idea by Gordon Gallup Jr. that some sense of animal self-awareness can be ascertained by gauging the reaction of an animal to a mirror (ostensibly seeing its own reflection).

miscibility: the capability of being mixed.

miso: a soup of fermented soy.

Mister Dog: a children’s book by Margaret Wise Brown. Belying a neatness fetish, Mister Dog smoked a pipe and wore a straw hat.

mistletoe: an obligate parasitic plant, though with evergreen leaves that perform photosynthesis. The host provides water and mineral nutrients. There are 1,300 mistletoe species.

mistletoebird (Dicaeum hirundinaceum): a bird native to Australia that eats assorted berries and insects, though favors mistletoe berries.

MIT: see Massachusetts Institute of Technology.

mite: a tiny arthropod in the subclass Acari, along with ticks. With 48,200 described species, mites are among the most diverse and successful invertebrates, having adapted to a vast array of habitats: living free in water or soil, and as parasites on plants, animals, and even mold. Studying ticks and mites is acarology.

mitochondrion (plural: mitochondria): an organelle that acts as a cell’s power plant, generating a supply of ATP. Mitochondria play other important roles in the cell life cycle, including growth and aging. Mitochondria maintain their own genome, independent of the cell nucleus. Some eukaryotic cells have multiple mitochondria, others none. Whereas human red blood cells have no mitochondria, liver cells may have over 2,000.

mitophagy: cell organelle recycling. Compare autophagy.

mitosis: the eukaryotic cell division process. Compare meiosis.

mitotic recombination: a relatively rare genetic recombination that occurs in somatic cells during mitosis.

mitral cell: a nerve cell in the olfactory bulb.

mixed emotion: the simultaneous experience of multiple emotions which may be incongruous.

mixotroph: an organism, typically a microbe, that can use a mix of different sources of energy and carbon. This affords taking advantage of different environmental conditions.

mnemonist (derived from mnemonic): a person with the superior innate recall.

moa: a large flightless bird endemic to New Zealand; the dominant herbivore there until hunted to extinction by men in the late 13th century. The 2 largest species reached 3.6 meters in height and weighed up to 230 kilograms.

moccasin (Agkistrodon piscivorus): a pit viper native to the southeastern United States.

mockingbird: a New World passerine known for their imitative songs, of 17 species in 3 genera.

model: a mathematical construct. See physical model.

modern physics: post-Newtonian conceptions of physics, including Einstein’s relativity theories and models related to matter at the subatomic scale. Compare classical physics.

modularity (biology): an organic system organized into identifiable units. Modularity appears at all biological scales, from macromolecules to organs and body plans.

modus operandi: a manner of operating.

Moho discontinuity: the boundary between the crust and mantle of the lithosphere; named after Andrija Mohorovičić.

moiety: a small molecule of a chemical functional group.

Moken (aka Sea Gypsies): a nomadic aquatic tribe that live among the hundreds of small islands that dot the coast of Myanmar (Burma) and Thailand leading out to the Andaman Sea.

moksha (aka mokșa, mukti): liberation from the perpetual cycle of reincarnation (samsāra) via realization (jnāna), according to Hindu belief.

mold (aka mould): a fungus that grows as multicellular filaments (hyphae). In contrast, fungi that grow as single cells are called yeast.

mole (chemistry): a standard molecular weight unit, with the unit symbol mol (because keeping that last letter in would make it too damn obvious). 1 mole equals 12 grams of carbon–12 (12C), the standard isotope of carbon.

mole (zoology): a small subterranean mammal found in the northern hemisphere, with powerful forelimbs for digging.

mole cricket: a burrowing insect with a cylindrical body 3–5 cm long, small eyes, and shovel-like forelimbs. Mole crickets have 3 life states: egg, nymph, and adult.

molecular motor: biological molecular motion agents. A molecular motor converts energy into movement or mechanical work. Protein motors are common.

molecule: a combination of atoms.

molecular geometry: the study of molecular shapes: the spatial arrangement of atoms in molecules.

mollusk (aka mollusc): a phylum of invertebrates. Mollusks are highly diversified in marine environments, comprising 23% of identified macroscopic marine species. There are also freshwater and terrestrial mollusks, such as snails.

molting (aka sloughing, shedding, ecdysis): shedding a body part, such as the epidermis (skin), during development or at a certain time of year, as with antlers. Arachnids, amphibians, and squamates are among animals which molt to grow.

Moluccas: see Spice Islands.

molybdenum (Mo): the element with atomic number 42. The metal molybdenum naturally occurs in various oxidation states in minerals; never as a free metal itself.

Molyneux’s problem: a philosophical question concerning the basis of knowledge and the senses: would a blind person be able to instantly recognize by sight what previously had been known only by touch if vision were restored?; posited by William Molyneux in 1688 to John Locke.

momentum (physics): mass times velocity. Momentum is a vector quantity, with both direction and magnitude.

monarch butterfly (Danaus plexippus): a large migratory butterfly. Its larvae dine on milkweed.

monarchy: absolute sovereignty by an individual. Compare despotism, autocracy.

monatomic: a molecule comprising a single atomic species. Helium is monatomic.

Moneke: the son of Martin the Ape in the 16th century German fable Reynard the Fox. The term monkey derived from this, albeit as a misclassification of monkeys as apes. See monkey.

monetarism (economics): the school of thought that emphasizes a government role in controlling the amount of money in circulation.

money: a medium of exchange, often, though not necessarily, symbolic; a fungible applicable to purchasing goods and services. Compare currency.

mongoose (plural: mongooses or mongeese): a small carnivore of 33 extant species, endemic to southern Eurasia and Africa.

monobasic acid: an acid with only 1 hydrogen ion to donate to a base in an acid-base reaction.

monochromacy: having a single type of vision receptor. Marine mammals, with only 1 color cone type, are monochromats, as are night monkeys.

monocot (monocotyledon): an angiosperm with a single embryonic leaf (cotyledon) in its seed. Compare dicot, eudicot.

monoculture: agricultural use of land for growing only 1 crop.

monogamy: a mating system comprising a male and female pair. Contrast polygamy.

monism: the metaphysical doctrine that there is a singular reality, either matterism or energyism. Contrast dualism.

monitor lizard: a large, venomous, carnivorous lizard in the Varanus genus, with ~79 species, native to Africa, Asia, and Oceania.

monkey: a primate, excluding apes.

monkey-flower (aka musk-flower): a flowering plant of 150 species in the genus Mimulus. Monkey-flower species diversity is greatest in western North America, with Australia another area of considerable diversity.

monochromacy: having a single type of vision receptor. Marine mammals, with only 1 color cone type, are monochromats, as are night monkeys.

monochronic (culture): a culture that views time as linear and divisible, and particularly monetary (time as money). Contrast polychronic.

monocot (monocotyledon): a plant with 1 embryonic leaf (cotyledon) in its seed. Compare dicot, eudicot.

monoculture: growing only 1 crop on a farm.

monoecy: the presence of male and female flowers on the same plant. Compare hermaphrodite.

monogamy: a mating system comprising a male and female pair. Contrast polygamy.

monogenesis: the false hypothesis by Charles Darwin that all human races descended from a single species.

monologue: prolonged one-way communication by an organism. Contrast dialogue.

monomer: a molecule that may bind with other molecules to form a polymer.

monopole: a magnetic pole considered (theorized) in isolation.

monophagy: an animal with a diet limited to a single specific type of food. Contrast polyphagy.

monophyletic: organisms descended from a single taxon; a clade.

monopoly (economics): a market condition where there is only 1 seller, with the power to set price and supply. Compare oligopoly.

monosaccharide (aka simple sugar): a simple carbohydrate with the formula (CH2O)n, where n = 3 (triose), 5 (pentose), or 6 (hexose). Glucose, fructose, and ribose are exemplary monosaccharides. See disaccharide.

monounsaturated: a fat molecule with one double carbon bond. Compare polyunsaturated.

montane: an ecosystem found in mountains, stratified by elevation.

monotheism: the belief in a singular god. Contrast polytheism.

monotheistic idealism: the idea that Nature is within the mind of God.

monotreme: a mammal that lays eggs. Although they were once more widespread, the only extant species are endemic to Australia and New Guinea: platypuses and echidnas (spiny anteaters).

montane: the biome of mountain regions.

mood: an emotive frame of mind.

Moon: Earth’s solitary satellite; the 5th largest satellite in the solar system.

mora (plural: morae): a phonological unit regarding syllable weight, related to emphasis and timing.

moral: conforming to a principle of appropriate behavior based upon respect of other life.

moral absolutism: the principle that acts are intrinsically right or wrong. See deontology.

moral philosophy: see ethics.

moral universe: the belief that a natural morality exists.

morality: the differentiation between social right and wrong based upon fairness. The philosophy of morality is ethics. A moral code is a creed of morality.

moray eel: an eel in the Muraenidae family, with 200 species across 15 genera. Moray eels are shy and secretive.

mordant: a chemical compound that sets dyes onto fabrics or tissue by forming a coordination complex with the dye, the combination of which attaches to the substrate. There are many mordants, including tannic acid and sodium chloride. A mordant is typically a polyvalent metal ion.

more (sociology): a folkway of central importance; a strongly held norm. See taboo.

Morgan Stanley (1935–): American investment bank and brokerage firm, formed by J.P. Morgan partners Henry Morgan and Harold Stanley in response to the 1935 Glass–Steagall Act, which required that banks could not pursue both commercial and investment banking, as it created an inherent conflict of interest within such a combined firm.

Mormonism: a Protestant Christian sect, founded by Joseph Smith in western New York in the 1820s. The term Mormon is derived from Smith’s Book of Mormon, which he claimed to have translated from golden plates with divine assistance. Unlike most other Christian denominations, Mormons have several canonical texts other than The Bible. Mormons consider polygyny favorably and believe in exaltation: eternal life in God’s presence, continuing to live as families (eternal marriage).

morning glory: a flowering plant of over 1,000 species in the Convolvoulaceae family.

Morocco: a monarchy at the northwestern tip of Africa.

morpheme: the smallest semantic language unit.

morphine (C17H19NO3): an opium extract, used medicinally for pain.

morphogen: a signaling molecule that directs cell movement and guides tissue development (morphogenesis).

morphogenesis: biological development of form.

morphology: the form and structure of an organism or other system. Compare physiology.

Morse code: a method of transmitting text through a series of short and long signals respectively denoted dots and dashes.

mosaic evolution: an evolutionary change in only part of an organism.

Mosaic Law (aka Law of Moses): ancient Jewish law, spelt out in the first 5 books of the Jewish Bible (Old Testament).

mosaic virus: a nontaxonomic name for viruses which cause plant leaves to speckle and stunt plant growth.

mosasaur: an extinct group of large marine reptiles, of 38 genera, which lived from the Early Cretaceous until the period’s end 66 MYA.

mosquito: a family of small, midge-like flies. The females of most mosquito species are blood suckers.

mosquitofish: a small freshwater fish in the Gambusia genus.

moss: a phylum of 12,000 species of small, soft, non-vascular plants that usually grow in clumps, typically 1–10 cm tall, though a few are larger. Moss are commonly confused with lichen. In their afterlife moss form peat.

moss rose (Portulaca): a flowering plant of 40–100 species found in the tropics and warm temperate regions.

moth: a flying insect related to the butterfly. Most moths are nocturnal. ~160,000 species are extant. Compare butterfly.

mother cell (aka parent cell): a cell that produces other cells.

motherboard (aka mainboard, system board): the main printed circuit board (PCB) in computers.

motile: capable of movement. Contrast sessile.

motion camouflage: movement that does not attract the attention of an intended target (typically a prey or predator).

motion parallax: a cue for depth perception based upon movement.

motivated reasoning: decision-making biased by emotion.

motivation: a stimulus that causes an organism to behave in a certain way. See desire.

motor protein: a class of proteins in cells which convert the chemical energy in ATP into movement.

mountain goat (Oreamnos americanus): a large, even-toed ungulate native to North America.

mountebank: a person who sells quack medicines.

Mousterian (industry): Middle Stone Age tool technology which represented refinements from Acheulean culture. Mousterian was named after an archeological site at Le Moustier, a rock shelter in the Dordogne region of France.

mouse (plural: mice): a small rodent of ~40 extant species.

mouse lemur: a nocturnal lemur in the Microcebus genus; the smallest primate.

mucin: a class of glycoproteins that form a viscous solution which acts as a lubricant or protectant; the main component of mucus.

mucus: a slippery secretion by animals of water and glycoproteins as protection against infection.

mucous membrane (aka mucosa): a membrane of epithelial cells over a layer of loose connective tissue.

mudra: a symbolic or ritual hand position or gesture in Hinduism and Buddhism.

mudskipper: an amphibious fish in the goby family that walks through the mud on its pectoral fins.

mujahedeen (singular and plural): a Muslim guerrilla fighter, especially in Afghanistan and Iran.

mulberry (aka fig): an angiosperm of over 1,100 species in ~38 genera. See fig.

mule: a hybrid between a male donkey and a mare (female horse). Compare hinny.

Müller glia: a glial cell found in the vertebrate retina that processes visual information.

Müller-Lyer illusion: an optical illusion devised by Franz Carl Müller-Lyer in 1889 – that the mind offsets the center point of an arrow (toward the tail).

Müllerian mimicry: poisonous species that share a common predator mimicking each other’s warning signals. The mimicry need not be visual: it may be any sense that a predator employs to select its prey. Named after its discoverer, Fritz Müller.

multi-stability (perception): given sensory ambiguity, the inclination to alternately experience distinct interpretations.

multicellularity: an organismal structure comprising multiple cells. Contrast pluricellularity.

Multics (an acronym for Multiplexed Information and Computing Service): a cooperative project between MIT, GE, and Bell Labs that began in 1964 to develop a scalable time-sharing operating system. Bell pulled out in 1969, convinced of the project’s economic infeasibility.

multimedia : the combined use of different media in software applications, such as sound and animation or video.

multiple inheritance (object-oriented programming): the ability of a class to inherit from multiple superclasses.

multiple sclerosis: a debilitating inflammatory disease in which the glia cells which direct myelin production are damaged.

multiplicity reactivation (cells): restoration from damage.

multipole: a form of monopole with no pole strength or net charge.

multituberculate: a group of rodent-like mammals that lived 165–35 mya.

multiverse: the idea that a multitude of universes eternally exist on a vast HD canvas. Many multiverse models are nonsensical in mistaking wonky math for possible reality (e.g., parallel universes). See cyclic cosmology. There are various distinct multiverse concepts, some far-fetched. These arise from the assumption that simplistic physical models mirror Nature. See many-worlds interpretation.

Mundaka Upanishad: a primary Upanishad, and one of the most widely translated. As with other Upanishads, the Mundaka chronology is unclear, but perhaps the 6th century BCE.

mung: a gathering of female animals for males to pick a mate. Contrast lek.

muon: an unstable lepton, similar to an electron.

murein (aka peptidoglycan): a polymer comprising sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria.

murre (aka guillemot (UK), turr (Canada)): a large black-and-white diving auk that spends most of its life over northern coastal seas, only venturing onto land for colonial breeding. There are 2 species in the murre genus (Uria): the common murre (U. aalge) and the thick-billed murre (U. lomvia).

muscle (tissue): 1 of the 4 primary animal tissue types. Muscle cells are capable of contraction, and so provide for movement. See also epithelium, connective (tissue), and intelligence (tissue).

muscle memory: a procedural memory of physical activity.

muscovite: a mineral high in aluminium and potassium.

muscular dystrophy: a group of muscle diseases that eventuates in weakening and breakdown of muscles.

muscular hydrostat: a set of muscles that can move without skeletal support. Since muscles can only produce force via contraction, different muscle groups must work against each other: one group lengthens by relaxation while another produces force through contraction.

mushroom: a fleshy, spore-bearing fungal fruiting body, typically produced aboveground. See toadstool.

mushroom body (corpora pedunculata): a brain structure in arthropods and some annelids, notably the ragworm.

music: sound perceived as patterned via repetitive elements.

musk: a class of aromatics originally named for the strong odor of a certain musk deer gland. Various plants and animals produce musky scents despite their often having distinctive chemical structures and molecular shapes.

Muslim: an adherent of Islam.

mussel (aka clam): a bivalve mollusk.

mustard (botany): any of several plants in the Brassicaceae (mustard/crucifer/cabbage) family.

mustard: a flowering plant in the Brassica genus with seeds that serve as a spice. { Spokes 4 }

mustard gas (sulfur mustard; (ClCH2CH2)2S): a cytotoxic and vesicant chemical warfare agent developed by Germany in 1916.

mustelid: a carnivorous mammal in the Mustelidae family, which includes badgers, minks, martens, otters, polecats, weasels, and wolverines. Owing to its diversity and lack of unified lineage, mustelid classification remains unsettled.

mutation: a change in a DNA sequence.

mutualism: a regular interaction between 2 organisms that provides mutual benefits.

mya: millions of years ago. my as an acronym for “million years” is deprecated in modern geophysics, in favor of Ma, shorthand for megaannum.

mycelium (plural: mycelia): a thread-like filament of mesh-like mass of fungal filaments (hyphae).

Mycenaean (civilization) (1600–1100 BCE): an ancient civilization during the Late Bronze Age. Mycenae is the historical setting for much ancient Greek literature and myth, including the epics of Homer.

mycoheterotrophy: a plant that is a mycorrhiza parasite.

mycoheterotrophyte: a plant that practices mycoheterotrophy.

mycology: the study of fungi.

mycophagy: fungus eating (by a fungivore or mycophagist).

Mycoplasma: a genus of tiny bacteria that have no cell wall.

mycorrhiza (plural: mycorrhizae or mycorrhizas): a mycelial fungus that has a symbiotic relationship with a vascular plant.

myelin: the dielectric (electrically insulating) material coating nerve cells, largely comprising fats and proteins.

myelin sheath: the myelin coating of an axon; an outgrowth of a glia cell.

Myers-Briggs Type Indicator (MBTI): an introspective questionnaire intended to reveal psychological preferences which indicate personality type, based upon a theory by Carl Jung. MBTI was developed by Katharine Briggs and her daughter, Isabel Myers, from the early 1920s, and published in 1944.

myoelastic-aerodynamic theory: a theory of vocalization corresponding with Bernoulli forces (negative pressure) on elastic tissue folds muscularly controlled (myo refers to muscles).

myoglobin: an iron- and oxygen-binding protein in vertebrate muscle tissue, employed for oxygen transport.

myosin: an ATP-dependent motor protein, best known for its role in muscle contraction, but involved in a wide range of eukaryotic motility actions.

Myristica: a genus of trees in the Myristicaceae family, with over 150 species native to Asia and the western Pacific. The most commercially significant species is Myristica fragrans, the source of mace and nutmeg.

myristicin (C11H12O3): a compound found in minute amounts in nutmeg, dill, and parsley; employed as a pesticide.

myrmecochory: a plant-ant mutualism. Some plants bribe ants to disperse their seeds by coating them with an elaiosome.

Myrmecolacidae: a family of insects in the Strepsiptera order, with 4 genera and ~98 species.

myrmecology: the study of ants.

Myrmica: a genus of 200+ species of ant, endemic to temperate and mountainous regions of Southeast Asia.

mystical: non-empirically obscure. The commonly bandied definition of involving something supernatural needs to confine itself to magical.

mysticism: the doctrine that knowledge of ultimate reality may be subjectively intuited.

myxamoeba (plural: myxamoebae or myxamoebas): a single amoeboid that forms a plasmodium (slime mold colony) when it finds friends.

myxobacteria (aka slime bacteria): a group of soil bacteria.

Myxozoa: a group of microscopic aquatic parasites. Once considered protozoan, myxozoans are instead cnidarians that shrank and dumped much their genome to make their livelihoods from infestation.