Q: When people go out to buy their dog a toy, what mistake do they commonly make?
A: They purchase popular toy colors like red or safety orange (the bright orange red of traffic cones or safety vests) that are difficult for dogs to see, says psychologist Stanley Coren in "Do Dogs Dream? Nearly Everything Your Dog Wants You to Know."
Tests show dogs have trouble seeing red, which can appear to them as dark brownish gray or even black.
Not that dogs are color-blind, as many people believe, but they are "color-challenged."
We humans have three different kinds of light-catching cones affording us our full range of color vision; dogs have only two.
University of California, Santa Barbara, researcher Jay Neitz tested dogs by showing them a set of three light panels -- two of the same color, the third different. Only if the canines picked out the lone color did they get a treat. Thus Neitz confirmed that dogs do see colors but many fewer than normal humans do.
Instead of seeing a rainbow of colors, "dogs see the world as basically yellow, blue and gray."
So, Coren says, that bright red toy so visible to you may not be what your dog sees.
"If your own pet version of Lassie runs right past the toy you tossed, she may not be stubborn or stupid. It may be your fault for choosing a toy with a color that is hard to discriminate from the green grass of your lawn."
Q: "Not only has the horse been outgunned by the car, but it faces the further indignity of not being able to keep up with itself," says one "Discover" magazine writer. What might he be driving at here?
A: First, let’s talk horsepower. In 1760 outside London, King George III housed about 30 horses, or only about one-fifth the horsepower of the typical 150- horsepower-engine in today’s compact car, says "Discover" magazine’s Corey S. Powell in "20 Things You Didn’t Know About Cars."
"By the formal definition of horsepower, which is the power needed to lift 33,000 pounds by 1 foot in 1 minute, a real horse musters only 0.7 horsepower."
Wow! It really can’t keep up with itself.
And some other surprising car facts: In a mishap that didn’t live up to the victim’s name, H. H. Bliss of New York City became the first documented U.S. auto fatality, on Sept. 13, 1899, after exiting a trolley car.
Fortunately, the average fatality rate per mile of driving has dropped by 80 percent over the past 50 years, largely due to seat belt use.
Q: From a Parma, Ohio reader: "Why is Greenland considered an island while Australia is a continent?"
A: Greenland’s surface area is roughly 836,000 square miles, while Australia at 2,941,000 square miles is 3.5 times larger, answers Dr. Matthew Edney, director of the History of Cartography Project. Moreover, Greenland is part of the North American tectonic plate, whereas Australia has its own plate, plus distinctive flora and fauna.
The real question, poses Edney, is why so many people think Greenland is of sufficient size that it should be considered a continent. The answer is that most world maps since the late 19th century have been made on the Mercator projection, but when used to map large areas on a single sheet, "it distorts areas exponentially."
On the basic form used for the world map, the equator is the central axis of projection, where the scale is correct; moving away from the equator, distortion increases so rapidly that the poles cannot be shown.
Therefore, Australia, near the equator, is shown relatively close to its proper scale, but Greenland, near the North Pole, appears greatly enlarged.