Kids are often credited for being ultra-curious, and rightfully so. How else would they learn the basics of functioning as among human beings, or of the universe, or within various complex institutions? We lose some of our inquisitiveness as we physically grow up, along with our knowledge base. People tend to become a bit overconfident when judging their cognizance when it comes to mundane subject matter. But how many of you will actually know the answer to these 5 basic questions?
1) Why do parrots imitate humans?
Parrots have vocal tracts that make them capable of human speech. While other species of birds can mimic sounds as well, parrots' lower vocal range allows them to more accurately replicate sounds, particularly human voices. From an evolutionary perspective, parrots' calls are learned through imitation instead of being developmentally hard-wired because it helped in the mating process. Parrots with above average imitative vocal skills usually have strong control over the neural functions of hearing and memory, sending a positive signal to future mates. Additionally, calls vary between divergent parrot clans. Keeping a distinctive sound allows for easy location of local, territory-holding mates. And once parrots have found their mates, their distinguishable call allows for easy communication.
2) Why is space black?
Space, contrary to earth, has too few air molecules to reflect the light of stars back to us. The molecules act like tiny mirrors, so the lack of them keeps space black, even close to the sun. But why don’t all the stars in the universe produce a bright, blinding glare all the time? Olber’s Paradox from the 1800s concluded that dust in space absorbed light from distant stars, heavily shrouding them and making them appear invisible. Later, scientists calculated that the light from starlight should heat dust enough to reflect light, creating a glowing space. Some scientists argued that light from stars was simply too far away to be bright, but opponents countered that if there were an infinite number of stars in the universe, then the light should still keep the sky bright all the time. Finally, astronomer Edward Harrison proved that stars and the universe were in fact finite, however debate still continues over the theory's accuracy and whether there's an "edge to the universe." And since light takes millions of years to travel to us from far distances, we can see as many as 10 billion years back in time by looking into space.
3) How do we hear the sound of the ocean in seashells?
Even weeks after coming home from the beach, the familiar tumultuous roar of the ocean can be heard in a cavernous shell, like a portion of the sea rests inside it. However, these sounds are the echoes of all the noises around it. Shells with many smooth inner surfaces provide excellent walls for sounds like music, doors slamming, and even your own heartbeat, to bounce off of and create a cacophonous roar.
4) Why are yawns contagious?
Many species yawn, but for different reasons. For example, male fish yawn when they spot competition, and lions yawn when they’re hungry. An outdated theory concluded that yawning increases oxygen flow to the brain, keeping humans more alert. However, current studies have shown that yawning provides a cooling effect on an overheated brain, which often occurs with sleep deprivation, and stops oxygen carrying blood from leaving the brain, which stimulates us to wake up. However, the causes of contagious yawning are quite inconclusive. Some data show it’s linked to empathy, as individuals with psychopathic traits and children with autism, groups that lack empathy, are less likely to yawn in social settings. New studies have even linked an increase in age with a decrease in contagious yawning; a multitude of variables can cause contagious yawning. Thousands of years ago, yawns were used to synchronize a group’s behavior, signaling hunting time or sleeping time.
5) Why do people say cats have nine lives?
Contrary to the popular belief of many six-year-olds, cats don’t in fact have nine lives. They're just very good at falling. Your cat could fall from a 30-story building and survive with just a few broken ribs or a bloody nose, while humans (and most animals) wouldn’t live to tell the tale. They have an excellent balancing mechanism in their inner ears, so if a cat is falling upside down, it can easily turn itself over in mid-air. The cat lands on all fours with its knees bent, so the impact of the fall doesn’t go straight to its breakable bones. And, cats are more likely to survive longer distance falls than short ones, because they have more time to reach terminal velocity. All objects accelerate at the same rate as they fall, but air resistance acts on an object to reach terminal velocity, at which the object stops accelerating downward, and instead falls at a constant rate. When cats reach this velocity, they spread their legs out, almost acting as a parachute that further increases their air resistance.