Why is the sky blue? -- Why are moths attracted to lights? -- Can the Great Wall of China be seen from space? -- Why were neckties invented? -- What causes jet lag and how can it be prevented and cured? -- Why do we yawn and why is it contagious? -- What is a blue moon? -- Does water travel down the drain in different directions in the Northern and Southern Hemispheres? -- Do you get wetter when walking in the rain than you do when running? -- Is one dog year equal to seven human years? -- Why do buses often come in threes? -- Why do women talk more than men do, but can't read maps as well as men? -- Why do people need sleep? -- Is the drink Red Bull dangerous? -- Why do people often wake up just before the alarm? -- Do we really use only 10 percent of our brains? -- How do mobile phones work? -- Was the 1959 moon landing a fake? -- When did the game Rock, Paper, Scissors begin? -- Why do people twitch as they fall asleep? -- What is the common cold and how is it cured? -- What is the Internet and how does it differ from the World Wide Web? -- When was toilet paper invented and what was used before then? -- Why do people dream? -- How similar are humans to apes? -- Who wrote the Bible, and when? -- Where does the saying "As mad as a hatter" come from? -- Why do women and not men take birth control pills? -- Why do people have tonsils? -- How intelligent are dolphins? -- How do people count cards in casinos? -- Why do some coins have ridges around the edge? -- Did Robin Hood actually exist? -- Where did the term "rock 'n' roll" come from? -- Why is the professional baseball championship called the World Series? -- How do people pick locks? -- What is the history of the Leaning Tower of Pisa?

Do hair and fingernails continue to grow after people have died? -- Why do people cry? -- Can babies hear voices while inside the womb? -- Are cats and dogs colorblind? -- How do people speed-read? -- Was Nostradamus able to predict the future? -- What is subliminal advertising and does it work? -- Why does the date for Easter change? -- How do salmon find their exact birthplace? -- What is the origin of the term "rule of thumb" -- Where did the name "Ku Klux Klan" originate? -- How do rabbits and hares differ? -- What is the small thing that hangs at the back of the mouth? -- What is the difference between an ocean and a sea? -- Why is New York City called "the Big Apple"? -- Why do men and women gain weight in different parts of the body? -- What makes a valuable diamond? -- Why do whales beach themselves? -- Why does coffee keep you awake? -- Why do phone numbers in movies all start with 555? -- Why is bellybutton lint generally blue? -- How did the marathon race begin? -- What are aphrodisiacs and do they work? -- Why does human hair turn gray? -- Why does catnip affect cats? -- How do mirrors work? -- Why is Friday the 13th thought to be unlucky? -- How did the word "shit" originate? -- How can you tell if someone is lying? -- Why do men feel sleepy after sex? -- Why do snooze alarms go off every nine minutes? -- Why is "God bless you" said after a sneeze? -- Why can't you tickle yourself? -- Why do bottles of tequila contain worms? -- Why do many prices end in ninety-nine cents? -- What is the difference between AIDS and HIV? -- How can direction be found without a compass? -- Where did the fabric denim originate and why is it stitched with orange thread? -- Why do people have appendixes? -- Why do golf balls have dimples? -- What is the origin of the term "OK"? -- Does an elephant truly never forget? -- Why does sweat smell? -- Why does metal rust? -- Why do we have earwax? -- Why do people shrink with age?

Why do men have nipples? -- What is acid rain and what causes it? -- What is the purpose of pubic hair and why is it curly? -- Does chewing gum really take seven years to digest? -- Why did Kentucky Fried Chicken change its name to KFC? -- Is drinking too much water bad for you? -- Why are unidentified people called John and Jane Doe? -- What is Coca-Cola made from and did it once contain cocaine? -- How do crocodiles and alligators differ? -- Why did the Romans wear togas? -- Why do we hiccup, and what causes them? -- Why do onions make people cry? -- Can it be too cold to snow? -- Why is getting married called "tying the knot"? -- Why do people stick out their tongues while concentrating? -- How does the Atkins diet work? -- What makes stomachs growl? -- Why do some people sometimes see "stars"? -- Is chocolate addictive? -- Is using a tanning bed bad for your skin? -- How does Viagra work? -- Why is a dollar called a "buck"? -- Where do flies and mosquitoes go in winter? -- Why are people's eyes different colors? -- Does shaved hair grow back thicker and darker? -- What are rainbows and how are they formed? -- Do swimming pools really contain a chemical that reveals urine? -- How did the saying "dressed to the nines" originate? -- Why do people get dizzy if spun around? -- What causes "ringing" in the ears? -- What are the origins of the hamburger and the hot dog? -- What is menstrual synchrony and does it exist? -- Does water pressure plummet during television commercials during the Super Bowl? -- Why do restaurants allow you to taste wine before buying it? -- What is the history of St. Valentine's Day? -- What are computer viruses and how do they work? -- Why does alcohol cause people to urinate so much? -- When was lipstick invented and what was its original purpose? -- Why does the sound of scraping fingernails make people cringe?

What is the difference between a hurricane and a typhoon? -- How did the word "cocktail" originate for some alcoholic drinks? -- Why is it thought that blonde women have more fun? -- Why is the pirate flag called the "Jolly Roger"? -- Why does the penis shrink when it's cold? -- Is the Caesar salad named after Julius Caesar? -- What is snot and why is it sometimes green? -- How do flies land and walk upside down? -- Why is a rabbit's foot considered good luck? -- Does speaking to plants encourage them to grow? -- What makes people get motion sickness? -- What is the horizon and is the distance to it always the same? -- Why do pregnant women get morning sickness? -- What is the origin of the tattoo? -- What causes people's ears to pop? -- What is the G spot and where is it? -- How do hummingbirds hover? -- What is cancer? -- Why do you never see baby pigeons? -- Why do people get acne? -- How did the "missionary position" get its name? -- Why don't igloos melt on the inside? -- Does wearing tight underwear affect a man's sperm count? -- Where does the expression "pipe dreams" come from? -- Why are parrots the only birds that talk? -- Why do people sneeze? -- Does sitting close to the TV or reading in poor light ruin your eyes? -- How did April Fool's Day originate? -- What is the difference between monkeys and apes? -- How can you tell if someone is flirting with you? -- Why is the number thirteen referred to as a "baker's dozen"? -- When and where did the game of chess originate? -- Why are the terms "bull" and "bear" used in connection with the stock market? -- What are the JFK assassination theories? -- Why does alcohol make people drunk? -- Does penis size vary depending on race? -- What makes animals warm- or cold-blooded? -- Why do pepper shakers have more holes than salt shakers do? -- What is the difference between a donkey, an ass and a mule? -- Is suicide illegal?

How do microwave ovens cook food? -- Is homosexuality a genetic trait? -- Did Dracula really exist? -- Why do kamikaze pilots wear helmets? -- Why do men often shiver after urinating? -- What are the Seven Wonders of the Ancient World? -- What causes a heart attack? -- Why do some beer heads disappear faster than others? -- What is hypnosis and is it possible? -- Where does the word "hooray" come from? -- Why are some men more likely to cheat on their partners than women are? -- Do camel humps contain water? -- What is gravity and Einstein's theory of relativity? -- Why do people crave salt, and why is too much considered bad for you? -- Are green potato chips poisonous? -- What is the difference between an herb and a spice? -- Do taxi drivers have better than average memories? -- Can stress cause illness or death? -- How can water be found in dry conditions? -- Why does the sound of running water give people the urge to urinate? -- Where did the term "red herring" originate? -- What are the greenhouse effect and global warming? -- Why was Stonehenge built? -- Why is the Mona Lisa painting so famous? -- What are crop circles and what causes them? -- Why do people say "Cheers" and clink glasses before drinking? -- How can a fire be lit without matches? -- What evidence exists about the Loch Ness monster? -- What is sea level and does it vary? -- What is the best way to immobilize or kill a person using bare hands? -- What caused the two World Wars? -- Which came first, the chicken or the egg?