d'espresso Skrevet 9. oktober 2015 Del Skrevet 9. oktober 2015 Hei! Er på siste del av en lengre oppgave i Exphil nå, og der skal man redegjøre for moderne fysikks syn på kausalitet.. Lest pensum (nesten, i alle fall.. mangler ingenting som penser innom dette temaet). Googlet og.. Kan noen i korte trekk forklare, eller peke meg i riktig retning..? Takk! Lenke til kommentar
Budeia Skrevet 9. oktober 2015 Del Skrevet 9. oktober 2015 Det virker som moderne fysikk forholder seg til den spesielle relatvitetsteorien. Det endret betydningen av ordet "simultanous" eller "simultan". https://no.wikipedia.org/wiki/Den_spesielle_relativitetsteorien Fant noe her: https://en.wikipedia.org/wiki/Causality_%28physics%29 Spesielt avsnittet In modern physics, the notion of causality had to be clarified. The insights of the theory of special relativity confirmed the assumption of causality, but they made the meaning of the word "simultaneous" observer-dependent.[5] Consequently, the relativistic principle of causality says that the cause must precede its effect according to all inertial observers. This is equivalent to the statement that the cause and its effect are separated by a timelike interval, and the effect belongs to the future of its cause. If a timelike interval separates the two events, this means that a signal could be sent between them at less than the speed of light. On the other hand, if signals could move faster than the speed of light, this would violate causality because it would allow a signal to be sent across spacelike intervals, which means that at least to some inertial observers the signal would travel backward in time. For this reason, special relativity does not allow communication faster than the speed of light. In the theory of general relativity, the concept of causality is generalized in the most straightforward way: the effect must belong to the future light cone of its cause, even if the spacetime is curved. New subtleties must be taken into account when we investigate causality in quantum mechanics and relativistic quantum field theory in particular. In quantum field theory, causality is closely related to the principle of locality. However, the principle of locality is disputed: whether it strictly holds depends on the interpretation of quantum mechanics chosen, especially for experiments involving quantum entanglement that satisfy Bell's Theorem.Despite these subtleties, causality remains an important and valid concept in physical theories. For example, the notion that events can be ordered into causes and effects is necessary to prevent (or at least outline) causality paradoxes such as the grandfather paradox, which asks what happens if a time-traveler kills his own grandfather before he ever meets the time-traveler's grandmother. 1 Lenke til kommentar
d'espresso Skrevet 9. oktober 2015 Forfatter Del Skrevet 9. oktober 2015 Tusen hjertelig takk! Det var midt i blinken Lenke til kommentar
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