Each and every day, whether we notice it or not, an endless current of change occurs without pause, flowing relentlessly on the river of time, through and around us. Surprisingly, we never see the vast majority of these vital processes. In fact we can't see them because these events happen much too quickly or too slowly for our human senses to perceive. Scientists are now opening new windows on this landscape, illuminating nature from the inner workings of atoms to the motions of the stars, from billionths of seconds to billions of years.