- In astronomy, absolute magnitude (M) is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object’s absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it were viewed from a distance of exactly 10 parsecs (32.6 light-years), without extinction (or dimming) of its light due to absorption by interstellar matter and cosmic dust. By hypothetically placing all objects at a standard reference distance from the observer, their luminosities can be directly compared among each other on a magnitude scale. For Solar System bodies that shine in reflected light, a different definition of absolute magnitude (H) is used, based on a standard reference distance of one astronomical unit.
- Alan Turing (plato.standford.edu)
Alan Turing (1912–1954) never described himself as a philosopher, but his 1950 paper “Computing Machinery and Intelligence” is one of the most frequently cited in modern philosophical literature. It gave a fresh approach to the traditional mind-body problem, by relating it to the mathematical concept of computability he himself had introduced in his 1936–7 paper “On computable numbers, with an application to the Entscheidungsproblem.” His work can be regarded as the foundation of computer science and of the artificial intelligence program.