Q: While life without physical pain may sound ideal, in fact it can be an even bigger pain. How so?

A: Consider the people whose sense of touch is disturbed so badly that they feel no physical pain, a condition caused by a mutation of the gene SCN9A, says David Linden in his book "Touch: The Science of Hand, Heart and Mind," as reviewed by Katie Burke in "American Scientist" magazine. Often they don't live beyond their teen years, as cuts and scrapes go unnoticed and lead to serious infection.

"Even fatal injuries cannot be felt": In one tragic case, a "fearless" child trying to impress some friends jumped off a building, got up and walked away. He died later that day from internal bleeding he could not feel.

A very different disorder of this genetic mutation "can result in pain-sensing neurons 'like machine guns with a hair-trigger...' Even mild stimuli can initiate bouts of agonizing pain." These sufferers, though, can live long, full lives, unlike their pain-free brethren.

Q: Go to your kitchen cupboard and take out any large drinking glass. Which do you think is larger... its height or its circumference?

A: Most people think the height is bigger, but here you need to recall the definition of "circumference," or the distance around, says Arthur Benjamin in "The Magic of Math." Try this: Use your thumb and middle finger on opposite sides of the glass to determine its diameter. It's easy to see that three of your finger diameters will be enough to take in the whole height of the glass. Since circumference equals pi times the diameter—where pi is 3.14—you know the glass is somewhat bigger around.

Q: "Tiger, tiger, burning bright, in the forests of the night..." But what if the tiger issues a voluminous roar instead?

A: No two tigers sound the same, identifiable by the pitch and duration of their roars, so it's a more reliable method for tracking than using hidden cameras or following pawprints, says "New Scientist" magazine. Such thinking has come out of the U.S.-based Prusten Project, a conservation initiative. In this manner, the animals can be tracked and traced in the wild. "Already, the project has installed recording equipment in a forest in Thailand."

This is a "roar achievement," quips the magazine.

Q: Forget Einstein's relativity, special or general. What did this cosmological guru have to say that would likely knock you for a loop? Do you have TIME for this one?

A: Lovely lyricisms surround the mystical notion of time, such as Henry David Thoreau's "Time is but the stream I go a-fishing in. I drink at it; but while I drink I see the sandy bottom and detect how shallow it is. Its thin current slides away, but eternity remains." But perhaps nothing is stranger than the words of Albert Einstein, who maintained that "time is just another dimension of the universe and that its passage is an illusion, suggesting that past, present and future coexist simultaneously," says editor-in-chief Stephen George of "Discover" magazine. In essence, then, there is no difference between the past and the future as both are set in stone. Don't even ask what this notion does to birthdays, anniversaries, deadlines?

As George quips, "If time is an illusion I suppose that would mean that Einstein really didn't come up with this idea 110 years ago — he's coming up with it at the same time I'm writing about it, and at the same time that George Ellis, a conscientious cosmologist, is disputing that selfsame view of the universe." Specifically, Ellis holds that it is dangerous to suppose that the future is set in stone because it robs us of our free will and moral accountability.

Send STRANGE questions to brothers Bill and Rich at strangetrue@cs.com