Physical world and mathematics

M. Stanley Whittingham

M. Stanley Whittingham, born Michael Stanley Whittingham, is a British-born chemist at Binghamton University who pioneered the intercalation lithium battery and shared the 2019 Nobel Prize in Chemistry.

M. Suhail Zubairy

M. Suhail Zubairy, born in Lahore, Pakistan, in 1952, is a University Distinguished Professor of physics at Texas A&M University known for quantum optics research and a graduate textbook.

M. van der Klis

Michiel van der Klis, born 1953, is a Dutch astrophysicist who discovered quasi-periodic oscillations in X-ray binaries and was professor at the University of Amsterdam.

Sep 20, 2026

M. Zahid Hasan

M. Zahid Hasan is a condensed matter physicist and Eugene Higgins Professor at Princeton University, known for the experimental discovery of topological insulators and Weyl semimetals.

M/M/1 queue

The M/M/1 queue, also known as the MM1 Model, is a single-server queueing model with Poisson arrivals and exponential service times, stable only when the arrival rate stays below the service rate.

M/M/c queue

The M/M/c queue, or Erlang C model, is a queueing model with Poisson arrivals served by c identical parallel servers, published by A. K. Erlang in 1917.

M2-brane

The M2-brane is a two-dimensional membrane of M-theory, named after the 1995 M-theory revolution, appearing as a classical solution of eleven-dimensional supergravity found by Duff and Stelle in 1990.

M3GNet

M3GNet (Materials 3-body Graph Network) is a universal graph neural network interatomic potential for periodic materials, introduced by Chi Chen and Shyue Ping Ong at UC San Diego in 2022.

M42 lens mount

The M42 lens mount, also called the Praktica or Pentax screw mount, is a 42 mm screw-thread mount for SLR cameras, introduced in 1949 and easily adapted to modern mirrorless bodies.

M5-brane

The M5-brane is a five-dimensional brane of M-theory and the magnetic dual of the M2-brane; coincident M5-branes are described by the six-dimensional (2,0) superconformal field theory.

M51-ULS-1

M51-ULS-1 is an ultraluminous supersoft X-ray source in the Whirlpool Galaxy, 28 million light-years away, host of M51-ULS-1b, the first candidate planet beyond the Milky Way.

Oct 21, 2026

M62H

M62H (PSR J1701–3006H) is a 3.70 ms millisecond pulsar in globular cluster M62; its companion M62H b, confirmed in 2024 via MeerKAT pulsar timing, has a 3.2-hour orbit and mass above 2.47 Jupiter masses.

M81

Messier 81 (M81, NGC 3031, Bode's Galaxy) is a grand-design spiral galaxy in Ursa Major about 11.6 million light-years away, discovered by Johann Elert Bode in 1774.

M82

M82, also called the Cigar Galaxy, is a starburst galaxy in Ursa Major about 12 million light-years from Earth, forming stars ten times faster than the Milky Way.

M82 X-1

M82 X-1 is the brightest ultraluminous X-ray source in the starburst galaxy Messier 82, about 12 million light-years away, and a leading candidate for an intermediate-mass black hole.

M87*

M87 is the supermassive black hole at the center of the galaxy Messier 87, with a mass of about 6.5 billion Suns, first imaged in April 2019.

Maar

A maar is a broad, low-rimmed volcanic crater formed by explosive interaction of rising magma with groundwater, cutting below the pre-eruption surface and underlain by a funnel-shaped diatreme, with the type locality in Germany's Vulkaneifel.

Maarten B. J. Roeffaers

Maarten B. J. Roeffaers is a Belgian chemist and full professor at KU Leuven known for optical microscopy methods that visualize working catalysts at the single-molecule level.

Maarten Schmidt

Maarten Schmidt (1929–2022) was a Dutch-born American astronomer at Caltech who in 1963 identified the redshift of 3C 273, showing that quasars are distant, extraordinarily luminous objects.

Maastrichtian

The Maastrichtian is the youngest stage of the Upper Cretaceous, spanning 72.2 to 66 million years ago and ending at the mass extinction that killed the dinosaurs.

Macassa Mine

Macassa Mine is an underground gold mine in Kirkland Lake, northeastern Ontario, Canada, owned by Agnico Eagle and one of the world's highest-grade gold mines.

Macaulay2

Macaulay2 is a free, open-source software system for research in algebraic geometry and commutative algebra, created by Daniel Grayson and Michael Stillman and funded by the National Science Foundation since 1992.

Macdonald polynomials

Macdonald polynomials are a two-parameter family of symmetric polynomials indexed by partitions, introduced by Ian G. Macdonald in 1987 to unify the Hall-Littlewood and Jack symmetric functions.

MACE-MP-0

MACE-MP-0 is a foundation machine-learned interatomic potential for materials chemistry, released in December 2023 and trained on about 1.5 million DFT configurations from the Materials Project.

MACE-OFF

MACE-OFF is a series of short-range, transferable machine learning force fields for organic molecules, built on the MACE architecture and introduced by University of Cambridge researchers in 2023.

Mach cone

A Mach cone is the conical shock front trailing behind an object moving faster than the speed of sound, its angle set by the Mach number.

Mach cutoff

Mach cutoff is the atmospheric refraction phenomenon in supersonic flight where, below the Mach cutoff threshold, sonic boom rays bend upward before reaching the ground, enabling boomless flight.

Mach number

The Mach number, or Mach speed, is the ratio of an object's speed to the local speed of sound, defining subsonic, transonic, supersonic, and hypersonic flight regimes.

MACH-IV (test)

MACH-IV, Machiavellianism Scale by Christie and Geis (1970): 20-item self-report questionnaire measuring Machiavellianism, the standard Dark Triad Mach measure, with known factor-structure and wording criticisms.