I keep my office like I keep my coffee: dark. So when the door creaked open, and the light streamed in, I knew it was trouble. The dame walked toward me and started firing off questions. She was the pushy sort, and she shot "˜em off rapid-fire: "Why's the sky blue? Why are tennis balls fuzzy? Why do llamas spit? Why? Why? Why?" The gal was merciless, and she didn't take "Go ask mom" for an answer. This was a four-year-old who needed explanations, and she needed "˜em fast. I looked over my shoulder, took a long swig of courage, then opened the drawer. I could see it was time to crack open this case.
THE WHY FILES
WHY DOES THE UNITED STATES PRINT $2 BILLS?
After 1963, the government pretty much gave up on trying to popularize the $2 bill. However, they did reissue the denomination (with newly-designed back) in 1976 to commemorate the nation's bicentennial. And even though about $1 billion of them were still in circulation in 1996, the Treasury decided to print $200 million worth of new ones. Why? Profit, of course. The bills cost about four cents each to print, and, if collectors buy them and put them away for safe-keeping, the government "earns" $1.96 on each one. Incidentally, this is the same reason the government loves making "state quarters" and commemorative postage stamps.
WHY DO TONGUES STICK TO METAL IN COLD WEATHER?
Few things could be funnier than the infamous tongue-on-a-flagpole scene in "A Christmas Story," but if it happened to you, you probably wouldn't be laughing. The scary reality is that your tongue is not the only body part that can bond to a cold, metal surface. Any moist, warm part of the skin can succumb to this cruel twist of nature, so even a sweaty palm on a cold doorknob can be a recipe for disaster. Metal makes a great conductor, which means it instantly responds to the heat of a person's body and crystallizes any moisture caught in between. If you're ever caught in this humiliating situation, a cup of warm water can help save your skin cells, but few things can save your reputation.
WHY DO WE CHRISTEN SHIPS BY BREAKING A BOTTLE OF CHAMPAGNE?
The whole thing may seem like a waste of a perfectly good bottle of bubbly, but a quick overview of early boat-christening practices should have you smashing bottles of Cristal in no time. Back in the day, Vikings used to christen a boat by splattering it with blood, which, like most asinine rituals, was meant to "please the gods" and thus guarantee a safe voyage. Seems like some sheep blood would have worked just fine, but the Vikings chose to use the blood of a young maiden. The practice, known as "roller reddening," involved strapping the victim onto the shipyard rollers that guided boats into the water, and then lowering the ship to sea. Luckily, someone convinced the Vikings that the gods might be just as happy with red wine, which eventually led to the usage of champagne in the late 17th century. Still think the tradition is silly? Consider this: No one performed the ritual on the Titanic upon its departure in 1912, and you know how that story ended.
WHY ARE TENNIS BALLS FUZZY?
The five o'clock shadow on a tennis ball is necessary; otherwise, the game would be too difficult to play. The textured edge helps to slow the ball down as it hits the surface of the court and the players' racquets. Without the gripping fuzz, a tennis ball would bounce too high and travel too fast, and the game wouldn't be nearly as much fun to watch.
WHY ARE OCEANS SALTY BUT NOT LAKES?
Oceans act like big dumping grounds for all the minerals (including salt) that wash off the land and get carried by rivers into the sea. As salt collects in the ocean, some of it evaporates with water, but most of it stays put. Evaporated salt and water take a ride in the clouds back over land, and the cycle continues. This means that rainwater does contain some salt, so, in truth, lakes are a little salty too. So why are the Great Salt Lake in Utah and the Dead Sea in the Middle East excessively salty? It's because they don't have an outlet. All lakes are fed by a water source (usually a river), and, in most lakes, the water flows out through a river as well, eventually reaching the sea. Salt lakes take water in from rivers or rain, but since they can only lose water by evaporation, some of the salt is left behind. Over time, these lakes have developed a high percentage of salt (even more than that of the world's oceans).
WHY DO LIGHTNING BUGS LIGHT UP?
When a male firefly larva finally gets old enough to develop wings, he does what every other male in the animal kingdom does when he can finally get away from home: He goes cruising for chicks. Fireflies can't entice the ladies with fancy dinners or nice cars, but they can emit glowing signals from their bodies because they have a bioluminescent enzyme known as luciferase, which the women just go crazy for. The downside is that fireflies only live for about seven days, which means their nighttime glowing expeditions are particularly frantic. So think twice before stuffing a bunch of those guys into a Mason jar; you may be ruining their one and only chance to "get it on" or, at the very least, seriously cramping their mojo.
More essential answers after the jump...
WHY DOES IT HURT SO BADLY TO CHEW ON ALUMINUM FOIL?
Sure, you're probably not snacking on balls of Reynolds Wrap every day, but most of us have had a little foil trespasser make it into our mouths every now and again. And when it happens, it can hurt really badly, but only if you have fillings in your teeth. Terrible as it is to imagine, when the silver in a tooth filling chomps down on aluminum, the reaction of the two elements creates a tiny electrical charge.
WHY IS YAWNING CONTAGIOUS?
First things first: Yawning is not triggered by a lack of oxygen in the body. These days, the prevailing theory claims that yawning is a primal behavior meant to signal the body's transition from one mental state to another, like moving from a sleep state to an awake state. So why's it contagious? Nobody's certain, but most believe that it used to be the way our animal ancestors would motion to their clans that it was time to move on to new territory or to start hunting for the day. Consequently, clan members would follow suit by repeating the transitional signal. Others claim that whatever stimuli would cause one person to yawn makes bystanders who view the act more susceptible to behaving in the same way.
WHY DOES IT HURT SO BADLY WHEN YOU HIT YOUR FUNNY BONE?
Because your funny bone isn't a bone, that's why. It's actually the ulnar nerve, which runs from your shoulders to your hands and is responsible for things like dexterity. The ulnar nerve sits rather close to the skin in the area around the elbow, so—like contact with any exposed nerve—it hurts really bad when you hit it. It's actually one of the body's biggest design flaws because we really could have used some more padding around that nerve. Primates like orangutans and chimpanzees have the same problem. So maybe the person who came up with the nonsensical name saw a chimp hitting his ulnar nerve, because, really, that's just funny.
WHY DO SOME PEOPLE HAVE "INNIE" BELLY-BUTTONS AND SOME PEOPLE HAVE "OUTTIES"?
No, it's not a conspiracy. The disappointing (i.e., boring) answer is that it's pretty random. Only seconds after you were dragged into this world, a doctor placed two clamps on your umbilical cord and cut it off a few centimeters away from your belly-button. Though this was probably your first emotionally scarring experience, the first scarring experience of a physical kind occurs when that little piece of umbilical cord still attached to your body eventually deadens and falls off, leaving—normally—a concave scar, or an innie belly-button. People with outties simply healed differently during this process. If you're bummed about your outtie status, mental_floss would like to remind you that things could be a lot worse: Several conditions, usually developed later in life, can cause urine, blood or, yes, even intestinal parts to leak out of the body by way of the navel.
>> Be sure to come back tomorrow for part II of the Y-Files. Oh, and if you enjoyed this piece, back issues are available for purchase here.