The Twins Paradox isn't a paradox. Special Relativity is only for inertial ( i.e. non-accelerating ) _frame_s for reference; the Twins Paradox involves acceleration, so calculus ( e.g. General Relativity ) is required. As for why one observes standard clocks ticking slower when they ( but not the observer ) are accelerated.. The coordinate speed of light ( in the far-distant, human _frame_ ) slows to zero at an event horizon of an ideal black hole because light ( climbing out of the gravity well ) is infinitely redshifted. So, for us humans, an infinite amount of time passes before an SI maser at the event horizon has a chance to move one SI wavelength ( 1 / 30.66 meters; 299,792,458 / 9,192,631,770 ). Jeff: There was a time when printed texts were considered outdated by the time the ink was dry. Technical magazines were more current. Now, changes can be tracked, daily, on the NET. But you are still using some old Einstein text as the standard for what is what. Trust your own smarts. My Einstein disproofs are easy enough for middle schoolers to understand. So, you may be... TOO smart!
