### Is there a lowest possible speed in physics?

by **Positor** on November 26th, 2010, 4:33 pm

Consider an ideal (frictionless) series of gears arranged to give progressively reduced speeds. If the gear system is run for a short period, e.g. 1 hour, and the theoretical distance travelled by the rim of the last gear (i.e. the one furthest from the power source) in that time is less than the Planck length, can that gear and its shaft be regarded as effectively stationary? If so, could the system be run in reverse, so that the "stationary" gear could impart motion to the preceding gears?

Is there a speed limit below which a body cannot be regarded as moving continuously? At extremely slow speeds, is motion to be thought of as being in discrete steps, with longer and longer intervals between them as speed is further reduced? And can this process be continued without limit?