2 Comments.

please would you tell me what "envelope-pushing" exactly means? I'm italian.
Thank you

Diana

To me it means working on the edges of what's possible, or discovering that what's possible extends a little farther than anticipated. Perhaps it comes from the field of aviation? The range of parameters within which a plane can successfully fly — speed, altitude, angle of attack, engine power, etc. — could be envisioned as forming a multidimensional shape, an "envelope" ... and when test pilots "push the envelope" they explore the space of possibilities to discover what can and can't be done. - ^z