relativity
/rɛləˈtɪvɪti
/- Welker claims his real concern is moral relativity.
- The apparent relativity of the moral impulse is an illusion which is created by the mind for the mind's own purposes.
- A response based on contemporary legal norms is unavoidable though the debate on cultural relativity and universality continues.
- General relativity explains the behaviour of gravity and its effect on both matter and energy.
- Penrose introduced the scope of modern physics and followed with a description of possible models of the universe based on criteria from the theory of relativity, including the effect of singularities.
The concept of relativity was set out in Einstein’s special theory of relativity, published in 1905. This states that all motion is relative and that the velocity of light in a vacuum has a constant value which nothing can exceed. Among its consequences are the following: the mass of a body increases and its length (in the direction of motion) shortens as its speed increases; the time interval between two events occurring in a moving body appears greater to a stationary observer; and mass and energy are equivalent and interconvertible. Einstein’s general theory of relativity, published in 1915, extended the theory to accelerated motion and gravitation, which was treated as a curvature of the space-time continuum. It predicted that light rays would be deflected, and shifted in wavelength, when passing through a substantial gravitational field, effects which have been experimentally confirmed.