Newtoninan mechanics were once thought to be based on a set of laws. Settled truth, it was thought. A law is no longer a law when it fails to hold under particular conditions, although it might still be useful. The bulk of practical human knowledge fall into this same category. All current laws will eventually find their way there too.<p>Conditions where relativity manifests seem way out extreme to us today. How extreme would standing on Jupiter have seemed in 1500 when your goal is not to land a rocket on the moon but to develop a more accurate calendar or navigate the Mediterranean? What will they say of Newtonian mechanics after 500 more years of hindsight?