Envelope

To get what you've never had, you must do what you've never done

Pushing the envelope

“Pushing the envelope” is a phrase that originated with American test pilots like Chuck Yaeger and John Glenn in the 1940s. It described max stress situations for the metal skin (“envelope”) of a jet aircraft. In other words, the plane was designed to fly safely up to a certain speed for a certain distance at a certain altitude. The job of test pilots was to “push...