I've had the hardest time grasping the bite of Parmenides' argument against change. His argument is summarized in ch. 5 "Article One: Potency Really Distinct From Act" of Reality: A Synthesis of Thomistic Thought by Réginald Garrigou-Lagrange:
If a thing arrives at existence it comes either from being or from nothing.
Now it cannot come from being (statue from existing statue). Still less can it come from nothing.
Therefore all becoming is impossible.
Now, can this be better understood as an application of Zeno's paradox, but instead of physical distance to be covered, a distance of time to be covered? For example, suppose I go from being short to being tall. Attach a device to my arm that continuously registers a "No" if I am short, and a "Yes" if I am tall. Then start the clock. Now, presumably, the device goes from registering a "No" at some point in time, to registering a "Yes" at another. However, we have an infinite number of half time distances to cover before we can go from "No" to "Yes", and hence eventually getting there is logically impossible.
What do you think?