No, Mary. David and I are just gently ribbing ...
Erick is sincere in showing us his diagram.
You know Leonard DaVinci made many intricate drawings of various flying machines. Very few of them had any remote chance of actually flying.
.... an unworkable theory.
Certainly, if you say so. Some of us are just stay-at-home tinkerers and thinkerers. Nothing worthwhile ever came of that, obviously....
Obviously, you are right and Leonardo's idea of human-powered flight by flapping wings -- just nonsense -- I mean, you know, obviously, -- nonsense
. No one could actually do that....
Leonardo was hardly first -- Brother Eilmer beat him to it by about 400 years
in actual gliding flight -- but no one was listening to him, either. (600 foot glide is pretty good as a first flight achievement -- even with a bad landing and a couple of broken legs).
It was true at the time that Eilmer and Leonardo worked these things out, that one could actually "fly" -- with far more effective range AND much more power
using a trebuchet to launch oneself ballistically -- but even if the destination were thus achieved -- I think that misses the point by a wide margin ... and with a worse landing even than Brother Eilmer managed.