NavList:

Sorry John,

re. Off topic, suggest new topic

I think I am one of those.

Not sure how it started, but the subject drifted into the area of “early graphic methods of plotting LOPs etc direct”. Which led on to questions about   Lunar clearance by same.

Perhaps for those still interested in this different topic, we could open a new discussion re-titled as such? I still have some un-answered questions, including one to you stimulated  by  your excellent book. (on which subject, thanks for that!)

Looking at it from a different perspective, in my years of experience in  medical research, great ideas often come out of roaming and wide ranging, “free-range”  discussions from diverse specialities and from lateral thinking.  I hope Nav list remains a “broad church” that continues to cover the wide range of interests locked up in the wonderful discipline of cel nav.

Sometimes, I agree, we need to focus and stick to the subject so that we can see the wood from the trees. But I personally know of  one brilliant medical colleague who narrowly missed a Nobel prize type discovery because he was so focused on what he thought was right in front of his eyes! He should have briefly looked left field, because there it was! (someone else, no more brilliant, did and indeed is now a Knight of the Realm and Nobel laureate!)

Best wishes and thanks to all who have joined in all these interesting discussions.

Francis