Is the present just a sharp line between the past and the future with no time at all, or is the present a short frozen unit of time?
Could time be quantized into a fundamental units? Like Planck time or some other briefest unit of time? Does then time itself jump from one time unit to the next time unit, because there is nothing between? Could everything at the smallest timescale be a frozen 3D-picture, similar to the 2D-pictures in a motion picture? Could this reality be something like a 3D-motion picture with pictures shown with a time frequency?
I guess we will never know if time is quantized if we don't measure that it is quantized. Like if we find something with a high frequency that are affected by the frequency of the fundamental time units. There is one such observation of the redshifted light from galaxies which seem to cluster to specific bands in the energy spectrum:
"The redshifted light we observe is consists of photons, discrete 'particles' of light energy. The energy of a photon is the product of a physical constant (Planck's constant) times the frequency of the light. Frequency is defined as the reciprocal of time, so if only certain redshifts are possible, then only certain energies are present, and hence only certain frequencies (or, equivalently, time intervals) are allowed. To the extent that redshifts of galaxies relate to the structure of time, then, it suggests an underlying quantization.
"In our newest theoretical models we have learned to predict the energies involved. We find that the times involved are always certain special multiples of the 'Planck time,' the shortest time interval consistent with modern physical theories." http://www.scientificamerican.com/article.cfm?id=is-time-quantized-in-othe&page=2