Blog

Remembering Glen Langdon's kindness, his contributions to computer engineering and arithmetic coding, and a compression utility I put together in his honor.

What a cryptographically relevant quantum computer would require, why RSA and Diffie–Hellman are vulnerable, and how Shor's algorithm turns quantum interference into factors.

What I taught in Dangerous World: nuclear physics, weapons effects, proliferation, biological and chemical warfare, and attacks on the systems that keep a civilization running.

A startup proposes to sell sunlight after sunset. We can calculate the added heat, from Los Angeles to the world's population centers, over a century of operation.

UC Santa Cruz fought over whether a professor could write a letter grade in a narrative evaluation. I was on the committee that said yes.

Larry McCraw was my Kenpo teacher. A small, fast champion, a mountain man, and a powerlifter after back surgery. Larry was, and remains, unstoppable.