Physics terms starting with M

Michelson Interferometer Optics m An optical instrument that splits a beam of light into two perpendicular paths and recombines them to create high-precision interference fringes. 2 d = m λ

Micrometer Screw Gauge Foundations of Physics mm An ultra-precise measuring tool that uses a calibrated screw thread mechanism to measure microscopic thicknesses or diameters. Reading = Main Scale + (Circular Scale Division × Least Count)

Microstate Thermodynamics & Statistical Physics N/A A specific detailed microscopic configuration of a thermodynamic system, specifying exact positions and momenta of all constituent particles. S = kB ln Ω

Milankovitch Cycles Geophysics & Environmental Physics Geologic Climate Cycles (Years) Cyclical variations in Earth's orbital eccentricity, axial tilt (obliquity), and precession that alter the seasonal and latitudinal distribution of solar insolation. Eccentricity (100ky), Obliquity (41ky), Precession (23ky)

Miller Indices Condensed Matter & Materials Physics Dimensionless Notation System A standardized three-integer crystallographic notation system (h k l) used to specify direction vectors and orientation of planes in a crystal lattice. (h k l) = Reciprocals of lattice axis intercepts

Minimum Deviation Optics Degrees (°) The minimum value of deviation angle achieved when light passes symmetrically through a triangular prism. n = sin[(A + δ_m)/2] / sin(A/2)

Minkowski Space Astrophysics, Cosmology & Relativity Flat 4D Spacetime Metric The flat four-dimensional spacetime manifold combining 3D Euclidean space and time used to formulate Special Relativity. ds² = -c² dt² + dx² + dy² + dz²

Mirage Optics N/A An optical illusion caused by continuous refraction of light rays passing through air layers with steep temperature and density gradients. n(z) = f(Temperature gradient)

Molar Heat Capacity Thermodynamics & Statistical Physics J/(mol·K) The heat energy required to raise the temperature of one mole of a substance by one Kelvin. C_m = Q / (n ΔT), C_p - C_v = R

Mole Foundations of Physics mol The SI base unit for amount of substance, containing exactly 6.02214076 × 10²³ elementary entities. n = m / M = N / Na

Molecular Dynamics Mathematical & Computational Physics Atomic Trajectory Simulation A computer simulation method for analyzing the physical movements of atoms and molecules by numerically integrating Newton's equations of motion. m_i d²r_i/dt² = F_i = -∇_i V(r₁, r₂, ..., r_N)

Molecular Motors Biophysics & Medical Physics pN (Piconewtons) & nm (Step Length) Protein-based molecular machines that convert chemical energy from ATP hydrolysis into mechanical work and linear movement. F_step ≈ 6 pN, Step Size d ≈ 8 nm (Kinesin on Microtubule)

Moment of Inertia Classical Mechanics kg·m² A quantitative measure of a body's rotational inertia - its resistance to changes in rotational motion about a given axis. I = ∑ m_i r_i² = ∫ r² dm

Momentum Classical Mechanics kg·m/s A fundamental vector quantity equal to the product of an object's mass and its velocity, representing its quantity of motion. p = m v

Monte Carlo Method Mathematical & Computational Physics Stochastic Numerical Method A class of computational algorithms that rely on repeated random sampling to obtain numerical solutions for complex physical systems. I ≈ (1 / N) ∑_(i=1)^(N) f(X_i) (Central Limit Theorem)

Moseley's Law Quantum & Atomic Physics Hz^(1/2) (Frequency Square Root) An empirical law establishing a linear relationship between the square root of characteristic X-ray frequency emitted by an atom and its atomic number Z. √ν = A (Z - b)

MOSFET Electromagnetism & Electronics A (Current) A Metal-Oxide-Semiconductor Field-Effect Transistor that uses an insulated gate voltage to control current flow through an underlying semiconductor channel. I_D = ½ μ_n C_ox (W/L) (V_GS - V_th)²

Most Probable Speed Thermodynamics & Statistical Physics m/s The particle speed corresponding to the maximum peak of the Maxwell-Boltzmann speed distribution curve. v_mp = √(2 kB T / m) = √(2 R T / M)

Moving Coil Galvanometer, Ammeter & Voltmeter Electromagnetism & Electronics A (Current), V (Voltage) An electromechanical instrument that measures small currents using magnetic torque on a pivoted coil, converted to an ammeter or voltmeter using shunts or series resistors. τ = N I A B = k θ; Ammeter: S = I_g G / (I - I_g); Voltmeter: R_s = (V / I_g) - G

Multiverse Astrophysics, Cosmology & Relativity Cosmological Hypothesis A hypothetical set of multiple co-existing universes that together comprise all of physical reality. Cosmic Inflation Bubble Universes & Many-Worlds Everett Branching

Muon Nuclear & Particle Physics MeV/c² (Mass Energy) A second-generation elementary charged lepton with a mass approximately 207 times greater than an electron. m_μ ≈ 105.66 MeV/c², τ_μ ≈ 2.2 μs, Spin = ½

Mutual Inductance Electromagnetism & Electronics H (Henries) The induction of an electromotive force in a secondary circuit loop caused by a time-varying current in an adjacent primary circuit loop. E₂ = -M (dI₁/dt), M = k √(L₁ L₂)

Terms starting with M