title: David W. Henderson
text: # David W. Henderson
  
  David Wilson Henderson (February 23, 1939 – December 20, 2018) was a Professor Emeritus of Mathematics in the Department of Mathematics at Cornell University. His work ranges from the study of topology, algebraic geometry, history of mathematics and exploratory mathematics for teaching prospective mathematics teachers. His papers in the philosophy of mathematics place him with the intuitionist school of philosophy of mathematics. His practical geometry, which he put to work and discovered in his carpentry work, gives a perspective of geometry as the understanding of the infinite spaces through local properties. Euclidean geometry is seen in his work as extendable to the spherical and hyperbolic spaces starting with the study and reformulation of the 5th postulate.
  
  He was struck by an automobile in a pedestrian crosswalk on December 19, 2018, and died the next day from his injuries.
  
  