Hey, Matt:

My friend read in a book somewhere that people are taller in the morning than they are at night. Is that possible? The book didn’t say why. Do you know why if it’s even true at all?

— Kid Dynamite, via email

If you wake up in the morning with your feet hanging over the edge of the bed, don’t be surprised. People really are taller when they’re huddled under the covers, occasionally hitting the snooze button. It’s because during the night your body can undo what gravity has done to it during the previous day. As gravity pulls down on your defenseless bod, the discs in your spine are squished and you literally become a shorter person. When you lie down, gravity loses its grip on your backbones, and they can resume their original position. The difference in height is only a few centimeters, but it is measurable if you have the proper gear.

Hey, Matt:

I’ve always wondered what happens to the tire tread on cars as it wears out. I mean, where does it go, onto the pavement, dust in the atmosphere, vanish into thin air? I figured if it was rolling onto the pavement then there would be huge globs of rubber on the road, or if it was in the air then it would cause everyone to have black lung.

— Don, San Diego

About 318 million tires are sold in the U.S. each year, sez the Rubber Manufacturers Association. Which of course means that there is an equal number of old discards whose treads have failed the penny test, exposing Lincoln’s dome to the elements. (If you’re real rich you probably use the quarter test and measure tread against Washington’s wig.) So you might well wonder where all that rubber went. Well, consider what’s going on when Grandma finally has to dust the elves off when they’ve been piled up for days in front of the tube on one of their Lifetime channel movie marathons. What’s she flicking off? Sand from the Sahara, industrial pollution from Ireland, dust from Denmark, bacteria from Belgium, viruses from Vietnam, and yes, tire tread from Turkey. Some tread gets stuck to the road — usually in patterns that veer across three lanes and off into the bushes, making us all wish we’d been there to see that happen. But most tire tread is worn off, bit by bit, and is whisked up into the upper air currents and carried across the planet along with bug parts and plant bits and whatever else can be lifted by the wind. All this crud in the air hasn’t reached crisis proportions yet, so you don’t have to worry about black lung in your lifetime.

Matt:

I hate it when my kids ask me questions that just make me scratch my head and say “Wha?” I got another one the other day when my daughter and I were sharing some (air quotes) quality time at McDonald’s. I don’t know how it came up, but I said something about my pinkie finger, and my daughter immediately demanded to know why the little finger is called “pinkie” and why the other fingers don’t have names. I really don’t have time for this kind of stuff. Can you help me?

— Very Good Mom, San Diego

Well, yeah, if I can finish the rest of your fries. And that shake? Thanks. So, anyway, pinck in Dutch means “small.” For some reason the Scots took a liking to the word and “pink” became the word of the day in the Scots’ language to describe almost anything small. The English saw how much fun Scotland was having with the word, so they grabbed it around 1700, and our little fingers got pinked. The color pink, the flower called a pink, and the disease pink eye all come from the same source as pinkie, but it would take another order of large fries and a shake to get that story out of me. As to why none of our other fingers are named, well, we can solve that. How about pinkie, then ringie, then birdie, then pointie, and, finally, opposable thumbie? Run those by your daughter and see what she says.