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Okay. Are you ready to switch Collected Wisdom on for another feast of fun and information? Just hit that button marked "I" to power us up. And whatever you do, don't hit that thing with the "O" on it.
THE QUESTION: On many electronic products, "on" and "off" are indicated by the symbols "I" and "O." What's their origin? asked Ken Walker of Jasper, Alta.
THE ANSWER: The symbols are actually a 1 (one) and a 0 (zero), corresponding to the two possible digits in a base-2, or binary, number system, explains Pierre Langlois of Montreal. (In a base-10 system, there are 10 digits, 0 to 9 inclusive).
"In digital circuits and computers, which use base-2 arithmetic, the common meaning for the digit 1 is 'true' or 'active,' while for 0 it is 'false' or 'inactive,' hence the correspondence with 'on' and 'off,' respectively."
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THE QUESTION: Why is virtually all the rice eaten in Asia white rice rather than the healthier brown rice? Paul L. Richard of Vancouver wants to know.
THE ANSWER: Toronto's Christopher Pinney says polishing and removing the outer rice bran greatly improves the shelf life of the rice, as keeping the bran on can cause it to become rancid quite quickly.
However, early polished white rice was expensive and could be purchased only by the upper classes, making it a status symbol. Demand increased accordingly. As harvesting and polishing technologies improved, white rice became cheaper and more popular.
"Eating the new white rice had its consequences, though," says Mr. Pinney. "By the late 19th century, a disease called beriberi was quite prevalent in Asia. This deficiency disease is caused by an absence of thiamine (vitamin B1) in the diet. This vitamin is found in the bran of brown rice."
Fortifying white rice with vitamins and minerals has now became part of rice production.
THE QUESTION: Why were refrigerators originally designed with the freezer on top so the least used section of the appliance was the most accessible? asked Jason Thomson and Tara Phillips of Ottawa.
THE ANSWER: "Early refrigerators were modelled on the icebox that preceded them," writes Chris Peachment of Barbados. "A large block of ice was placed at the top of the unit, above the foods to be cooled, and convection air circulation resulted in the cool air falling down from the ice."
In early refrigerators, he says, the freezer part consisted of a hollow box of sheet metal with the coolant tubes in it or on it. This mimicked the block of ice.
However, today's frost-free fridges "use a fan to move the air instead of convection, so the design could be changed and bottom freezer units are now available."
But the last word on this goes to Herb Roblin of Napanee, Ont. "The freezer was originally put on top so fat guys (like me) could just reach in and get the ice cream without having to bend over."
HELP WANTED
Why is the skin on a bald man's head shiny when the rest of his skin isn't? asks Calgary's Roger Marler.
P. Briant of Toronto wonders why characters in forensic TV shows never turn on the lights at crime scenes but wander around with flashlights.
Send answers (and questions) to wisdom@globeandmail.com. Include your name, location and a daytime phone number.
