Blue Ridge Mountains

Escher dice

Myth of the squirrel proof feeder

Flower by Yuan Zhang

Black rat snake, Durham, June 2013

Azalea in backyard, Durham, March 2013

Sophie Gromoll, Charlottesville, November 2012

Hiking in Banff with Ed Perkins and Nathanael Berestycki

Durham house before we moved in

House in Ithaca Feb 27, 2010

Raccoon on suet feeder in Ithaca

Turkeys in tree in Ithaca.

View of backyard, Ithaca.

Signing the book, NAS induction April 2008

Snow on April 17, 2006 in Ithaca