SPACE AND TIME
SYSTEMS THEORY
A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z

                  
  • HOME
  • ABOUT
  • CATEGORIES
  • SITE MAP
  • COPYRIGHT
  • ADVERTISE
  • CONTACT
    •

    entire Web this site



    causality

    The principle that a precisely determined set of initial conditions will always result in the same effect at a later time. Causality was a basic tenet of classical physics which assumed, both physically and philosophically, that it would always be possible to establish the initial state of a system to any desired degree of accuracy. The impossibility of such a precise determination and the consequent breakdown of causality at the subatomic level is a fundamental result of quantum mechanics and, in particular, of the Heisenberg uncertainty principle.

    In relativity theory one event can have a causal influence on another only if energy or information sent from the first reaches the second. See also causal structure.

    Causality and unity
    "Science is all about cause. Now, if really everything is connected to everything, if there really is only a oneness, everything then affects everything, and the whole idea of causality has to be revised."

      – Willis Harman, Metaphysics and Modern Science
    Causality on a large scale would be undermined should some means be found to (1) open a portal enabling matter to travel backward in time, or (2) send a message into the past, or, equivalently, at a speed faster than that of light. Just such a breakthrough was claimed in a paper in Physical Review Letters (May 22, 2000) based on the work of Anedio Ranfagni of the Italian National Research Council. See also time and time travel.

    The Scottish philosopher David Hume held that causes and effects are not real, but instead are imagined by our minds to make sense of the observation that A often occurs together with or slightly before B. All we can actually observe are correlations, not causations. This is also expressed in the logical fallacy, "correlation implies causation."


    Reference
    1. Krasnikov, S. V. "Causality Violations and Paradoxes." Physical Review D, 55 (6): 3427-3430 (1997).

    Related categories

       • SPACE AND TIME
       • PHILOSOPHY
       • SYSTEMS THEORY



    Also on this site:

    Encyclopedia of Alternative Energy & Sustainable Living
    Encyclopedia of History
    Transport Concepts & Designs (partner site)


    BACK TO TOP