Thomson (1881) first demonstrated electromagnetic field's role in inducing mass. Heaviside (1889) simplified Thomson's work to m = (4/3) E / c². Poincaré (1900) predicted electromagnetic field as fictitious fluid with mass
Supermassive black holes (SMBHs) are extremely large, ranging from hundreds of thousands to billions of solar masses. Only a few galaxies show clear dynamical evidence for SMBHs. The M-sigma relation suggests strong connection between black hole mass and galaxy velocity dispersion
Kilogram (kg) is the base SI unit of mass. Gram (10^-3 kg) is an SI derived unit. Tonne (t) is SI-compatible for masses above 10^3 kg
Weight equals mass multiplied by gravitational acceleration (g = 9.8 m/s²). Weight is measured in Newtons (N), mass in kilograms (kg). Gravitational acceleration can be expressed in meters per second squared (m/s²)
Gravity is universal and depends on masses and distance between objects. Universal gravitational constant G is 6.673 x 10^-11 Nm²/kg². Distance between objects (d) must be in meters (m)
Force is the push or pull exerted on an object to make it move. Newton's second law relates force to mass and acceleration. Greater mass requires greater force to move an object