  Consider a car moving off from rest at exactly noon. What is its state of motion at the instant of change? If it is in motion, when did it start? And if it is motionless, when could it ever begin? This problem was explored by Medlin (1963), Hamblin (1969), and others. Put this way, a solution for at least some special cases is readily available. Locate the time origin \(t = 0\) at noon. If the car’s position function \(f\) is given by, say, \(f(t) = t^{2}\), then its speed is \(2t\). If motion is defined as having non-zero speed, then the car is motionless at \(t=0\). On the other hand, at all \(t \gt 0\) it is in motion, so there is surely no puzzle about when it could ever begin: there is no first instant of motion.