Azrael wrote:Look at gravity. We consider it a proven fact today (well, proven theory rather than hypothesis). Thus, making decisions using our understanding of gravity (e.g. we will fall from a building if we step out the window) is rational. However, let's say tomorrow that our friends at CERN do something completely unanticipated and disprove the theory of gravity. That would make future decisions using the old theory of gravity irrational. But it would not reverse the rationality of our decisions at the time. We would not have been acting irrationally. We still would have been wrong.
Question for my own interest: Is it rational or irrational to use Newtonian physics in everyday scenarios? We know they're wrong - relativity is more accurate - but, for most things, they're not wrong enough to matter (for high-precision things like GPS they are, but for driving a car five miles to meet your friend, relativistic effects are negligible). Is it thus irrational to use a tool we know to be wrong, or is it rational as we know it gives the correct output to the degree of significance we care about? (I realize that even if it is irrational, it's danged *useful*, just because the equations are easier to work with.)
Or, does holding in mind the caveat "I know that this is just an approximation to the true answer which is close enough for my purposes" make it rational, as we're not truly holding the belief that it's right (which, for someone who knows of general relativity, would be irrational), just that it gives approximately accurate predictions for these sorts of scenarios (which has been borne out by the evidence provided by past trials)?