Wired 13.06: Time's Up, Einstein

"Lynds' paper, 'Time and Classical and Quantum Mechanics: Indeterminacy vs. Continuity,' is the latest chapter in a story that begins with Zeno and runs through Newton and Einstein to today. The question they struggled to answer: How does matter move through time and space?

Newton described motion as a change in position over time. (In the process of figuring that out, he invented calculus.) That allowed for infinite series of infinitesimal steps, which polishes off Zeno. But for his model to make sense, Newton needed what he described as 'absolute, true and mathematical time, which of itself flows equably without relation to anything external.' It's a God clock, ticking out discrete instants, or, if you prefer, a universal CPU, doling out reality one cycle at a time, a series of static instants giving only the appearance of motion like the successive frames of a movie.

But Einstein didn't buy it. The heart of relativity is that everything depends on your point of view - if you're traveling at close to the speed of light (a constant), then time moves differently for you than for your slowpoke friends back home. Einstein died before he had worked out the implications of his own brilliant ideas. Among the problems left unsolved: Time could go faster or slower (or even backward), but was it divisible? And were there irreducible 'atoms' of time, quantum flecks now called chronons?" (more at link)
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