Acknowledgements 379 Traversing an Infinite plane with a Line Illustrated by James Tagg Spear and Hunter Illustrated by James Tagg Hilbert Hotel Video Link Kind permission of BBC, hosted on YouTube Holding Infinity in Your Hand Photograph by James Tagg Number Quiz 1 Illustrated by James Tagg Number Quiz 2 Illustrated by James Tagg Donate a Random Number Illustrated by James Tagg Which Number is Random Illustrated by James Tagg Smallpox Virus 3d4Medical.com/Corbis Smallpox Child Associated Press, SANTOSH BASAK Chapter 9 Donald Rumsfeld US Army, Wikimedia, PD Kurt Gédel, any Likeness is Accidental Unknown, Wikimedia, PD IAF Rule 164 IAF rules excerpt PM Paul Hermans, Wikimedia, CC3 Amazon Listing for PM Amazon excerpt (not in print version) 1+1 = 2, PM (1) PM excerpt 1+1 = 2, PM (2) PM excerpt Konigsberg’s Bridges Bogdan Giusca, Wikimedia, PD Peano Portrait Materialscientist, Wikimedia, PD Beer Mug, Table and Chair Photograph by James Tagg Einstein and Gédel Kind permission of the Archive of the Institute of Advanced Study Chapter 10 Alan Turing Portrait National Portrait Gallery Enigma Machine Sperling, Wikimedia, PD Can you decode this? Illustrated by James Tagg Correct the code Illustrated by James Tagg Lego Turing Machine www.LegoTuringMachine.org Old Fashioned Relay Mechanism Wikimedia, Signalhead, CS3 3D Printing Machine 360b / www.shutterstock.com Block Print from ‘No Silver Bullet’ Wikimedia, PD Chapter 11 Fred Brooks Copyright owned by SD&M, Wikimedia CC3 Web Page (James Tagg’s Home Page) Screen capture by James Tagg Dilbert Software Specification DILBERT © 2006 Scott Adams. Used By permission of UNIVERSAL UCLICK. All rights reserved. Long Multiplication Illustrated by James Tagg A Hypercube in Two Dimensions Mouagip, Wikimedia, CC3 Impossible Shapes, Devil’s Tuning Fork Illustrated by James Tagg Halting Program Illustrated by James Tagg Four Color Problem chas zzz brown, Wikimedia, CC3 Dalek Trouble Birkett 1981, Perm