For my fellow MathPhys nerds, Bang-bang control is a serious area of Automatic Controls in Mechanical Engineering (also known as the dumping ground for Physics when a theory becomes well-established, e.g., Thermodynamics, Quantum Mechanics, etc.) that may provide a wonderful ice-breaker for you at your next pizza party or whatever on those occasions where an actual girl shows up. They all love double-entendre, let's be frank.
Anyway, in addition to the link above, here's a sample where Bang-bang is introduced in my college textbook (in 1978) "Introduction to Automatic Controls", by Harrison and Bollinger, page 367:
"Bang-bang control is an approach which involves the strategic switching of maximum corrective actions. It provides optimal control in cases where the requirement is for either minimum error, or minimum time. As an illustration of a minimum-time problem, consider an automobile at rest; we wish to bring it to rest a block away in the least amount of time. Obviously, full throttle followed by full braking is the solution. This is bang-bang control, that is, the strategic switching of maximum corrective actions."
There's more but we'll leave it as an exercise for the reader.
Figure 3-10 Bang-Bang Control with Soft Start Circuit, from here.