The measure of a kilogram gets revised, as do other metrics

Q. “When School Got Cancelled Because of the Super Bowl,” the headline reads. When did THAT happen?

A. In 2001, on the island of Guam, an “unincorporated organized territory” of the United States, much closer to the Philippines than to the continental U.S., says Dan Lewis on his “Now I Know” website. As American citizens, islanders have adopted many mainland customs, including an interest in the big football game. But because Guam sits in the Chamorra Time Zone (a 15-to-18-hour shift forward, depending on the game’s location), kickoff was 9:30 Monday morning. “Year after year, Super Bowl Monday on Guam is marked with half-empty classrooms as kids (and some teachers, too) take the day off to watch the big game.”

In 2001, Guam’s Department of Education (DOE) called a strategic “time out,” drawing on one of its unused typhoon makeup days in the school schedule, “to give everyone a day off on the football-created pseudo-holiday that year.”

Fans were no doubt delighted but approval was not universal. According to the “New York Times,” one local paper berated the DOE for using the day “spuriously on trivial matters” and called it “a dangerous precedent.” Since then, there have been no reports of school in Guam being cancelled for the Super Bowl. Q. You may never have been on a safari, but that word and others have travelled through time and place to settle in the English language. Can you define these words and their origins: “aubade,” “kurbash,” “postiche” and “prosopography”?

A. “Safari,” you know, is “an expedition to observe (or, in the past, to hunt) wild animals in their natural habitat,” says Anu Garg on his “A.Word.A.Day” website. “Aubade” (O-bahd), from the French, Spanish and Latin “albus” (white), means “a morning song, poem or music.” “Kurbash,” “a whip, especially one made of hippopotamus or rhinoceros hide,” has its origin in Arabic and Turkish.

Derived from the French, Italian and Latin is “postishe” (poh-STEESH), a “hairpiece” or an “imitation” or “sham.” Finally, “prosopography” has its roots in German, Latin and Greek and means “a study of people in a group, identifying patterns, connections, etc.: a collective biography.” Its earliest documented use was 1577.

Q. The two scientists have had the equation tattooed on their arms, along with a French phrase, which in English translates as “for all times and for all people.” What are they celebrating?

A. As of May 20, 2019, the kilogram will no longer be defined by a metal cylinder carefully secured under several bell jars and sequestered in a controlled environment near Paris, says Emily Conover in “Science News” magazine. Instead, the mass of a kilogram will be defined by a fundamental constant of nature known as the Planck constant, “fixed at exactly 6.62607015 x 10 (to the minus 34th power) kilograms times meters squared per second.”

In 1795, France adopted a standardized system of units, the metric system, known formally as the International System of Units, with the goal that the seven units should be accessible to everyone and last forever. But the kilogram fell short of this, as did three other units. On May 20, 2019, the kilogram, as well as the ampere (unit of electric current), kelvin (temperature) and mole (amount of a substance), will conform to the ideal.

Though most people won’t notice the change, metrologist David Newell and physicist Stephan Schlamminger of the National Institute of Standards and Technology in Maryland will herald the event in distinctive fashion.