You’ve probably heard the term “pushing the envelope.” You may also know that it means to push the limits or boundaries of performance. But where did the phrase come from and why would you push an envelope?
The phrase isn’t referring to a mail envelope as you may have surmised; but rather a mathematical envelope. The Envelope is defined as “the locus of the ultimate intersections of consecutive curves”.
Take a look at the image below.
In this two dimensional image you can see that it slightly resembles an envelope. The mathematical explanation is a little dry and complex to try and explain but basically- inside the graphed area= bad, outside= good. At least that’s what I gathered.
The phrase originated within the field of aeronautics. Essentially the term describes the upper and lower limits in which it is safe for a plane to fly. It takes into account the plane speed, altitude, maneuverability, wind speed, etc.
The term was used widely during World War II but became popular after publication of Tom Wolfe’s book about the space program, The Right Stuff (1979).