Mathematicians Disprove Conjecture Made to Save Black Holes
> In classical physics, the universe is predictable: If you know the laws that govern a physical system and you know initial state, you should be able to track its evolution indefinitely far into the future. ... [According to physicist Demetrios Christodoulou:] "This is the basic principle of all classical physics going back to Newtonian mechanics. You can determine evolution from initial data."<p>This is a famous mantra repeated by physicists but it is not correct. Newtonian physics cannot even predict the future positions of three body from their initial positions. And Newton knew and stated that his doctrines could not predict planetary orbits in long term and he invoked the very scientific and physical notion (or maybe footballers term) of Hand of God. Thus, Newton claimed his doctrine could not make accurate prediction not because they were wrong but because God erred to create the universe according to Newton’s doctrines. Consequently, according to Newton, God once in a while nudged the orbits to make them move correctly according to Newtonian doctrines. According to Newton himself initial states cannot predict long term behavior.<p>So how come NASA can predict so accurately planetary motions by using the so-called Newtonian Mechanics? The answer is easy: by not using Newtonian mechanics. NASA uses sophisticated mathematical methods or numerical integration to calculate orbits. But since they use as a unit conversion factor the strategically named Newton's Constant of Gravitation as one of their mathematical terms they feel they are justified to declare that they use Newtonian mechanics to compute orbits.<p>So what happened is that at some point, maybe in the 18th century this philosophical -not physical- assumption entered the physics literature and gained the status of truth after centuries’ of repetition. But if we question the mantra we see that the so-called classical theories do not claim that they can predict future states by the initial state. Phycists do.