Editing Predictability (section)

==Predictability and causality==

[[Causal determinism]] has a strong relationship with predictability. Perfect predictability implies strict determinism, but lack of predictability does not necessarily imply lack of determinism. Limitations on predictability could be caused by factors such as a lack of information or excessive complexity. 
 
In experimental physics, there are always observational errors determining variables such as positions and velocities. So perfect prediction is ''practically'' impossible. Moreover, in modern [[quantum mechanics]], [[Werner Heisenberg]]'s [[indeterminacy principle]] puts limits on the accuracy with which such quantities can be known. So such perfect predictability is also ''theoretically'' impossible. <!-- [To the author: please, take care that the indeterminacy principle defines the state of a particle to be indetermined until it is observed and, therefore, if it is not observed it cannot be measured. It has nothing to do with the accuracy of measurement.] -->

=== Laplace's demon ===
[[Laplace's demon]] is a supreme intelligence who could completely predict the one possible future given the Newtonian dynamical laws of classical physics and perfect knowledge of the positions and velocities of all the particles in the world. In other words, if it were possible to have every piece of data on every atom in the universe from the beginning of time, it would be possible to predict the behavior of every atom into the future. Laplace's determinism is usually thought to be based on his mechanics, but he could not prove mathematically that mechanics is deterministic. Rather, his determinism is based on general philosophical principles, specifically on the principle of sufficient reason and the law of continuity.<ref>{{Cite journal|last=van Strien|first=Marij|date=2014-03-01|title=On the origins and foundations of Laplacian determinism|journal=Studies in History and Philosophy of Science Part A|volume=45|issue=Supplement C|pages=24–31|doi=10.1016/j.shpsa.2013.12.003|pmid=24984446|bibcode=2014SHPSA..45...24V |url=https://hal.archives-ouvertes.fr/hal-01610331/file/article.pdf}}</ref>