Today was the first day in several weeks that I got a chance to climb. While some climbers who were new to the area came by to chat their dog made herself at home.

It's not uncommon for computer manufacturers to sell the same hardware at multiple price points, with the lower‑priced models artificially slowed down. This isn't new, nor is it a deep dark secret, but it struck me as a bit weird when I first heard about the practice. (I was young and naïve to the ways of the business world).

I get the impression Amazon sometimes delays shipment according to the price paid. They use an economical next‑day carrier for shipments within California, but the customer doesn't enjoy that speed if they didn't pay for it. An order I placed this month with the cheapest (i.e., free) shipping option was shipped via a next‑day service—but only after Amazon sat on the order for five (calendar) days. Older electromechanical power meters had a rotating disk that let you gauge your rate of energy use at any moment. The disk made one revolution for each watt‑hour (i.e., each 3600 joules) of energy used. You could calculate how much power an appliance was drawing from how much faster the disk spun when you had the appliance turned on.

If you ever wondered how to glean the same information from a no‑moving‑parts meter like the one shown: the dots under the rightmost numeral are a "watt disk emulator". A dot turns dark or light with each watt‑hour used. (The "kWh" legend next to the dots refers to the numeric reading, not the dots.) The dots march left‑to‑right if you're consuming energy, right‑to‑left if you're sending energy into the grid.

Happy nineteenth, everyone. The position shown here arose in the last game of a chess tournament in St. Louis this month. It's black's turn; what's the only move that doesn't result in black losing the game?

click to reveal answer For about a week now I've seen the same lizard in the same spot day after day. He clings to the side of my house just below the eaves, about ten feet off the ground. I don't know what he thinks about but I permit myself to admire his example of composure and equanimity. He looks at me when I walk by.

He goes somewhere else in the nighttime and returns in the morning, except for Thursday when I didn't see him at all. The Moon was close to Mars and Saturn in the sky that day and perhaps he decided to keep a low profile until the baleful influence of that conjunction had subsided.

Ernest Barnes, Bishop of Birmingham, wondered how a creature as excellent as man could fail to be immortal. "His mind is a far finer instrument than anything that had appeared earlier—he knows right and wrong. He can build Westminster Abbey. He can make an airplane."

Yeah, but can he do this— I'm not sure which of these events surprised me the most:

• At Madrid-Barajas Airport last Friday, a passenger showed up late enough that his flight had already pushed back from the gate. He jumped to the ground from the jetway and ran after the plane.
• He was let on the airplane.
• A spokesman for the Spanish airport authority said, "The only person who can answer the question of why he acted like he did is the man who protagonized this incident."

Maybe I don't get out enough, but I was taken aback by protagonized as a transitive verb (although the meaning was clear enough). The aback‑takenness faded after I found out that protagonizar is an established verb in Spanish and Portuguese. Amazon Prime Air is registering freight airplanes with prime numbers. Their first Amazon-branded plane (a Boeing 767) has tail number N1997A. Now that they've gotten a mundane choice out of the way (Amazon went public in 1997), I'll be curious to see what other primes they pick.

If the prime number theme was intended to be endearing to geeks (and it is), the "Amazon One" text painted near the cockpit windows fails. One is not prime. Nor is it zero, the geek's choice of where to start numbering things. And this isn't Amazon's first plane, it's just the first they painted their name on. The president of the leasing company (which provided ten planes to Amazon before this one) jokingly said, "This is Amazon 11, as far as we’re concerned."