- theory of relativity (physics) the theory that space and time are relative concepts rather than absolute concepts
- general theory of relativity a generalization of special relativity to include gravity
- special theory of relativity a physical theory of relativity based on the assumption that the speed of light in a vacuum is a constant and the assumption that the laws of physics are invariant in all inertial systems
- theory of gravity (physics) the theory that any two particles of matter attract one another with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them
- general relativity a generalization of special relativity to include gravity
- refractivity the physical property of a medium as determined by its index of refraction
- theory of probability the branch of applied mathematics that deals with probabilities
- correlativity a reciprocal relation between two or more things
- relativity the quality of having significance vis-a-vis something else
- peripheral device (computer science) electronic equipment connected by cable to the CPU of a computer
- Einstein's theory of relativity (physics) the theory that space and time are relative concepts rather than absolute concepts
- special relativity a physical theory of relativity based on the assumption that the speed of light in a vacuum is a constant and the assumption that the laws of physics are invariant in all inertial systems
- principle of relativity (physics) a universal law that states that the laws of mechanics are not affected by a uniform rectilinear motion of the system of coordinates to which they are referred
- theory of gravitation (physics) the theory that any two particles of matter attract one another with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them
- reflectivity the capability of quiet thought or contemplation
- derivative a compound obtained from another compound
- transitivity (logic and mathematics) a relation between three elements such that if it holds between the first and second and it also holds between the second and third it must necessarily hold between the first and third
- Theodore Harold White United States political journalist (1915-1986)
- territorial division a district defined for administrative purposes
- overactivity excessive activity