In Memorium - David W Henderson (1939-2018)

On December 19, 2018 we drove from Philadelphia, where we visited David's siblings, to Winterthur. It was a beautiful morning - sunny, with light frost covering fields, windy scenic road to the museum. There we enjoyed Garden Tour and then display of Christmas decorations, decided that we should return in spring to see all those beautiful flowers; had lunch - tasty wild mushroom soup. I asked David - would he like some pecan pie, and he answered - why not. How could we know that that was our last meal together... I wanted to stop for night at Lewes but David said we should continue a little further. We stopped at Bethany Beach. Checked in hotel and asked where could we have a nice meal. We were suggested Cottage Cafe, just across the road. I wish we would never tried to cross that road... It was the darkest day of the year. It became the darkest day of my life.

Remebering David here are some of his writing about mathematics from his journals.

10/5/1975

One learns by being confronted with an image different from one’s own image until one is confronted with a block in themselves. Learning is the breaking thru that block such that one sees more clearly. 

Mathematics (or should I say geometry?) is looking at how we see (view) our universe. The whole universe not just space-time but the mental and spiritual universe also.

December/77

It helps us to see what is behind the forms we construct to hold us in. These forms protect us, guide us, help us. These forms are formed by one’s consciousness.

To me mathematics have to be experienced/ In music we have musical notation ( or musical theory). Analogous we have mathematical notation and mathematical theory. But to, me the real meaning is directly experienced. Like listening to music.  

1981

By “experience” I mean more than physical experience. We experience ideas and images. We experience “seeing” the whole ball with its center all at once. We experience ourselves growing (changing). All I can physically senses is some aspects of myself at a given instant in time. Yet I have an image of (sense of) my life as a whole changing from one point in time to another. It’s very similar to imagining the ball as a whole

Intro to Math 451 Fall 1991

 Geometry can say something about you.Geometry is a way of looking at your world. Take charge of it – make it yours. Understand how you see things and see how you understand things.

Think of what we are embarking on together as a stroll in the woods. I will show you paths that I have trod and point to what I have seen. I have been there many times before – but oh! – there is much more to see that I have not yet seen. You, with your unique vision, will point out to me things that I have passed by. Feel free to explore – look under stones, down in hollow stumps. You can find a rivulet of water that if followed will lead to the sea. But just as valuable are the little surprises that spark something inside – a trillium in a spot of sun, a scarlet eft wriggling under a fallen leaf. Do not hurry “to get somewhere” – linger a while—listen—see what’s around where you are.