Euler's laws of motion also Euler's equations (rigid body dynamics). The distribution of internal forces in a deformable body are not necessarily equal throughout, i.e. the stresses vary from one point to the next. This variation of internal forces throughout the body is governed by Newton's second law of motion of conservation of linear momentum and angular momentum, which for their simplest use are applied to a mass particle but are extended in continuum mechanics to a body of continuously distributed mass. For continuous bodies these laws are called Euler’s laws of motion. If a body is represented as an assemblage of discrete particles,
Clarke's three laws into any typeface and size from Albertus Extra Bold to Zurich Calligraphic", referring to his memory of "seeing and hearing Linotype machines which slowly converted ‘molten lead into front pages that required two men to lift them’". A fourth law has been proposed for the canon, despite Clarke's declared intention of stopping at three laws. Geoff Holder quotes: "For every expert, there is an equal and opposite expert," which is part of American economist Thomas Sowell's "For every expert, there is an equal and opposite expert, but for every fact there is not necessarily an equal and opposite fact", from