Christmas dinner staple gets its name from the country in roundabout way

Q. When it comes to food sizing, when might more be less than it seems?

A. “It’s harder to evaluate increases in the size of food servings than to judge decreases,” reports University of California Berkeley “Wellness Letter.” According to several studies in the “Journal of Experimental Psychology,” subjects who took part in a downsizing test were fairly accurate but when supersizing was involved, they “greatly underestimated” the numbers. Even professional chefs and servers who should have had a sense of food quantities were equally error prone.

Researchers hypothesize that “it’s easier to gauge a decrease in portion sizes because there is a ‘natural lower bound’” of zero, below which nothing goes, whereas when portions increase, there’s no upper bound to help determine how big something has become. Overall, “this may be why people are likely to notice when their favorite brands reduce the size of their packages, while being less aware when quantities increase.” Yet it’s not just a matter of feeling cheated or preferring to avoid losses but, the research suggests, it’s also a matter of perception.

Q. Accidentally mistype your credit card number into a website and you’re likely to get an immediate notification of the error, before any communication with your bank. Why? Are you ready for this one?

A. Not all 16-digit numbers are valid candidates for credit card numbers. According to Richard Webb in “New Scientist” magazine, there is a simple arithmetic procedure which checks validity, patented in 1954 by Hans Peter Luhn of IBM. Suppose you type in 0123456789012345 as your credit card number. The Luhn algorithm goes like this:

(1) Reverse the sequence of the digits, giving 5432109876543210.

(2) Add up the first, third, and fifth digits, and so on, to get 5+3+1+9+7+5+3+1 = 34.

(3) Double each of the second, fourth, and sixth digits, and so on, giving 8, 4, 0, 16, 12, 8, 4, 0. If any of these numbers have two digits (like 16 and 12), replace them with the onedigit number obtained by adding the two digits together (16 becomes 7, 12 becomes 3). Then add up all eight numbers to get 8+4+0+7+3+8+4+0 = 34.

(4) Add together the results of steps (2) and (3), giving 34+34 = 68. Only if this number ends in 0 is the entered credit card number a valid candidate. Since 8 is not 0, the entered number 0123456789012345 is not valid.

The Luhn test is a quick and convenient way of screening out most typos: it will flag any single-digit error and almost all transpositions of two adjacent digits.

Q. If the centerpiece of your Thanksgiving dinner is turkey, you might take a moment to ponder how the bird ended up with the same name as the country Turkey. So, how did it?

A. “Turkeys are indigenous to the U.S. and Mexico; in fact, Europeans only first came into contact with turkeys roughly 500 years ago,” likely during Cortes’s 1519 expedition to Mexico, says Dan Lewis in his book “Now I Know.” Five years later, the birds had reached England from the eastern Mediterranean Sea aboard merchant ships manned by so-called Turkey merchants, since much of the area then was part of the Turkish Empire. Back in England, buyers called the fowl “Turkey birds” or just “turkeys.”

Within 10 years, they had been domesticated, and by the turn of the century the word “turkey” had been in the English language long enough that Shakespeare used it in his play “Twelfth Night” (1601).

As Lewis says, “To this day, we’re simply carrying on the mistake of a few confused English-speaking Europeans.”