The Time Uncertainty Interval: This is from appendix 5 (The Science of Time) of my new book, How to Time Travel, due to be published on Amazon early September 2013.
Since the smallest unit of time is only definable as the Planck interval, this suggests there is a fundamental limit to our ability to measure an event in absolute terms. This fundamental limit to measure an event in absolute terms is independent of the measurement technology. The error in measuring the start or end of any event will always be at least one Planck interval. This is analogous to the Heisenberg uncertainty principle, which states it is impossible to know the position and momentum of a particle, such as an electron, simultaneously. Based on fundamental theoretical considerations, the scientific community widely agrees that the Planck interval is the smallest measure of time possible. Therefore, any event that occurs cannot be measured to occur less than one Planck interval. This means the amount of uncertainty regarding the start or completion of an event is only knowable to one Planck interval. In our everyday life, our movements consist of a sequence of Planck intervals. We do not perceive this because the intervals are so small that the movement appears continuous, much like a watching a movie where the projector is projecting each frame at the rate of approximately sixteen frames per second. Although each frame is actually a still picture of one element of a moving scene, the projection of each frame at the rate of sixteen frames per second gives the appearance of continuous motion. I term this inability to measure an event in absolute terms “the time uncertainty interval.”