Similarly, when people pass each other moving in opposite directions, there is always the choice of passing on the right or the left. It may seem peculiar to be using a facet of digital systems design as a means to illuminate the nature of change. But in fact digital systems such as computers were actually first envisioned as purely conceptual devices, to clarify issues in mathematics such as the nature of numbers and methods of reasoning. The engineering of computer systems provides a mirror for the general human effort to build a stable, reliable, predictable world. Often this mirror can show more explicitly and clearly the problems and paradoxes that arise but obscurely and mysteriously in the general effort.
Metastability is the pragmatic manifestation of the paradox of change.
It is not possible to build a device that can with perfect reliability report the time at which some feature of the world changes. On to next page. Back to top page.