In this season of giving and getting, you’ve got to admire the marketing savvy of the One Laptop Per Child project. They named their introductory sales campaign “Give One, Get One.” The computers cost $200 apiece. For a donation of $400, you send one machine to a child somewhere far away (Afghanistan, Cambodia, Haiti, Mongolia […]

The latest cute trick from Google is a service for producing quantitative graphics on demand. For example, here’s a bar chart of the traffic to this web site over the past year:

The cute part is how you get Google to produce the graphic. The whole specification—including data, scales, labels and stylistic preferences—gets packed into a […]

It’s time for my bimonthly self-promotional horn toot. The new issue of American Scientist is now available online, and paper copies should soon be stuffing mailboxes everywhere. My “Computing Science” column is on a new class of “holographic” algorithms invented a few years ago by Leslie G. Valiant of Harvard. The ideas have been further […]

Don Elgee, a retired teacher of mathematics and computer science from Ottawa, sends the following inquiry:

In hockey, when a team is down by a goal with about one minute to go, the goalie is pulled in favor of another offensive player. This illustrates a key point in the strategy of most games.
The object is not […]

I have a few questions for the complexity theorists among us.
Have you ever tried to explain to your grandmother why NP is named NP? Does she get it when you say that problems labeled NP-complete are the hardest problems in NP, but NP-hard problems might be harder, and not in NP?
My concern here is not […]

Above: A throbbing, wheeling mob of several thousand restless starlings, near a strip mall in Clayton, North Carolina, 27 October 2007. Below: Snow geese on maneuvers near Ashburn, Missouri, 12 November 2004.

In the 1930s, Edmund Selous argued that flocking behavior could be explained only through some form of animal ESP: “thought transference” was the only […]

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.)

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 […]

Hardware is hard, whereas software is soft; the people who named these things knew what they were talking about.
A while ago, I volunteered to help a friend upgrade the disk drive of an Apple iBook. My first clue that this was going to be a fun project was learning that we needed a special […]