Two of the best science-blog articles of 2007 appeared early in the year at Cosmic Variance. They were written by John Conway (not the John Conway, the other John Conway) and gave an inside view of what happens in a large experimental collaboration when there’s a hint of glory in the air. The CDF experiment—one […]

When is a tree (large, woody plant) not a tree (connected acyclic graph)?

This has something or other to do with the topic of the previous post.
(The tree (?) is a crepe myrtle near the campus of North Carolina State University in Raleigh.)

David Aldous asked me that question over lunch one day. I didn’t have an answer, so he explained: In the simplest model of human genetics, you get half your genes from each parent, a fourth from each grandparent, and so on. Thus the fraction of your genes contributed by each member of the nth generation […]

The drawing below, brazenly swiped from a 1964 Martin Gardner column, illustrates the solution to a well-known puzzle. If you stack n bricks on a table, how far can you make them extend over the edge without toppling?

The answer given, for bricks of unit length, is one-half the nth harmonic number, the sum of the […]

The new issue of American Scientist is now available both on the web and on paper. The subtitle of my “Computing Science” column makes the following rash assertion:
Multicore chips could bring about the biggest change in computing since the microprocessor
It’s always wise to be a little skeptical of such superlative claims. In Redmond, Washington, […]

This morning I am enjoying the benefits of jet lead. My watch says it’s 7:30, but the hotel-room clock reads 4:30, so I have a few hours free to lie awake and solve the world’s problems. As a warmup exercise I’m doing mental arithmetic. I’m dividing integers, and trying to figure out how I do […]

From the Dorling Kindersley Eyewitness Travel Guide to the Pacific Northwest, page 218:
In spite of its name, False Creek is not a creek at all….