In physics, a rigid body is an idealization of a solid body of finite size in which deformation is neglected. In other words, the distance between any two given points of a rigid body remains constant in time regardless of external forces exerted on it. Even though such an object cannot physically exist due to relativity, objects can normally be assumed to be perfectly rigid if they are not moving near the speed of light.
In classical mechanics a rigid body is usually considered as a continuous mass distribution, while in quantum mechanics a rigid body is usually thought of as a collection of point masses. For instance, in quantum mechanics molecules (consisting of the point masses: electrons and nuclei) are often seen as rigid bodies (see classification of molecules as rigid rotors).
Read more about Rigid Body: Kinetics, Geometry, Configuration Space
Famous quotes containing the words rigid and/or body:
“It’s fairly obvious that American education is a cultural flop. Americans are not a well-educated people culturally, and their vocational education often has to be learned all over again after they leave school and college. On the other hand, they have open quick minds and if their education has little sharp positive value, it has not the stultifying effects of a more rigid training.”
—Raymond Chandler (1888–1959)
“The body dies; the body’s beauty lives.
So evenings die, in their green going,
A wave, interminably flowing.”
—Wallace Stevens (1879–1955)