## One Flip Sends Many Bits

* Another coins on a chessboard puzzle *

Cropped from Ashley’s TwiCopy source |

Hou Yifan and Maurice Ashley are champions of chess in several senses. Hou just regained the Women’s World Champion title by defeating Mariya Muzychuk of Ukraine 3-0-6 in their match which ended today in Lviv. Along with her male Chinese compatriots who reign as Olympiad team champions, she headlines an extraordinary growth of the game in southeast Asia. Ashley became the first ever grandmaster to play a tournament in Jamaica where he was born and has been one of the game’s premier video commentators and ambassadors for over two decades. The past two years he teamed with entrepreneur Amy Lee of Vancouver to create and run the Millionaire Chess open tournaments in Las Vegas, to raise the professional profile of the game.

Today Ken and I present another puzzle in our “Coins on a Chessboard” series, theming it after Ashley’s “Millionaire Square” promotion.

Read more…

## Stonefight at the Goke Corral

* Will there be any man left standing? *

Sensei’s Library player bio source |

Lee Sedol of South Korea, who is currently ranked #4 on the unofficial GoRatings list, may be on his way to being #5. AlphaGo, a computer project sponsored by Google DeepMind, is ahead 2-0 in their five-game match.

Today I take stock, explain some of what has happened, and briefly discuss the prospects for AI and human ingenuity.

Read more…

## David Johnson: 1945-2016

* David just passed away *

David Johnson was a computer theorist who worked on many things, with special emphasis on the care and treatment of hard computational problems.

Ken and I are sad today to hear that David just passed away.

Many will announce this sad event; we expect that the whole community will express how much they miss David. He was unique among theorists in his dedication to see how hard so-called “intractable” problems really are. He dedicated much of his career to building *challenges*: A typical one asked you to design an algorithm that solved some hard problem, often an NP-complete one. These challenges were of great importance in pushing forward the field of attacking difficult but important problems.

Read more…

## A Matter of Agreement

* On the 2015 Turing Award *

Mirror image of source |

Whitfield Diffie, Martin Hellman, and Ralph Merkle publicly broke the yoke of symmetry in cryptography in the 1970s. Their work created the era of modern cryptography—all previous work, including the great work of Claude Shannon in 1949, implicitly assumed that the system must be symmetric.

Today Dick and I congratulate Diffie and Hellman on winning the 2015 ACM Turing Award and discuss the contributions of all three.

Read more…

## The Pierce-Birkhoff Conjecture

* A kind of hierarchy collapse? *

Cropped from father-son bio source |

Garrett Birkhoff was a mathematician who is best known for his research on lattices, and also his work on teaching of abstract algebra. He was at Harvard almost his whole career.

Today we wish to discuss a conjecture that he made with Richard Pierce that remains open today.

Read more…

## Coins on a Chessboard

* A 35-year-old puzzle with extras *

DeLong Lecture Series source |

Maxim Kontsevich has established deep connections between algebraic geometry and mechanisms of physics. He won a Fields medal in 1998 for “contributions to four problems of geometry” and recently won one of the inaugural Breakthrough Prizes in Mathematics, having earlier won the corresponding prize in Fundamental Physics. He divides his time between the University of Miami and the Institut des Hautes Études Scientifiques (IHES), which boasted Alexander Grothendieck at its inception. His IHES bio says that he is known for

…drawing on the systematic utilization of known deformations of algebraic structures and the introduction of new ones that have been revealed to pertain to many other questions where there were no

a-prioriconnections.

Today we discuss a much lighter topic he thought up as a teenager that uses coins on a chessboard.

Read more…

## Waves, Hazards, and Guesses

* Some matters of gravity in science *

Moshe Vardi is famous for many things, including his brilliant turn as the Editor-in-Chief of the Communications of the ACM. In the current issue he contributed an Editor’s Letter titled “The Moral Hazard of Complexity-Theoretic Assumptions.”

Today Ken and I want to comment on Moshe’s piece and the larger issue of guesses and possible hazards in science.

Read more…