[Jeff]

Yodas Luke

You wrote-: "I cannot see the fingers of the pianist playing Mozart that misses a key, but I can hear it. Must everything been seen to know?"

I think that's a weak argument. You are using your auditory sense organ to assess the accuracy of a pianist's note-playing. That's appropriate because you are using the appropriate sense organ to sense sound waves. However, if you want to assess whether the pianist's fingers are moving in space properly, then you must use the appropriate sense organ - the visual sense organ (or its appropriate surrogate substitute, a high speed swing video camera).

If the clubshaft hosel is actually moving around the clubhead sweetspot in space during the golf swing, then surely it must be visually-apparent.

Jeff.