Our kids see the world with different eyes. Nothing can escape their attention — their curiosity truly has no limits! They’re constantly asking questions and want grown-ups to give immediate answers. But, all too often, such questions leave us scratching our heads.
Today, Bright Side presents 11 of the most often asked questions, complete with answers that should help to quench your little one’s thirst for knowledge!
11. Why does water boil?
When water heats up, its molecules begin to move about. As this movement intensifies, the distance between the molecules grows larger and larger. Finally, there comes a moment when the ties between the molecules become too weak. The molecules fly apart and become water vapor. This process is called ’evaporation.’
10. What keeps airplanes in the air?
What keeps a 162-ton ’Boeing-747′ from falling out of the sky? The force at work here is called ’lift.’ Lift is generated when air flows over and under an airplane wing simultaneously. Because air moves faster over the top of the wing, it exerts less pressure there. At the same time, the dense air underneath the wings pushes the plane upwards. The higher the speed at which the plane is traveling, the stronger the lift.
9. Why is snow white?
When looked at separately, each snowflake looks colorless and transparent. Then how come snowbanks appear white? The answer is that when snowflakes form a large mass, they tend to refract and reflect the sunlight. The reflected light is white because our sun is also white (even though passing through atmosphere makes sunlight look yellow).
8. Why can’t human hair naturally be blue?
Human hair contains pigments that can make it look black, brown, yellow, or red. Our hair also contains tiny air bubbles. The combinations of pigments and the numbers of air bubbles present in the hair determines the color. Pigments available in our hair cannot produce a blue or green color when combined.
7. Why do astronauts float in space?
Contrary to what many people think, astronauts aboard the International Space Station aren’t free from the pull of gravity. Earth’s gravity affects all objects in orbit. As for the weightlessness effect — it is present because the station and its inhabitants are actually falling towards the Earth’s surface at 7.9 km/s (4.9 mi/s)! But, the high altitude at which the station is situated makes this fall a perpetual one. It’s as if the orbiting object keeps missing hitting our planet’s surface, and it flys around the Earth instead. Imagine an elevator cabin, falling down from the top floor of a skyscraper. A person inside such cabin would experience temporary weightlessness. Astronauts in orbit experience exactly the same thing, but on a continuous basis.
6. Why is the sky blue?
As the sun’s rays enter our planet’s atmosphere, they get scattered and refracted. Initially white, sunlight splits into seven colors of the rainbow. Because blue is scattered more than other colors, it ends up dominating our sky’s palette. But the sky is never ideally blue due to the presence of other colors in the spectrum.
5. What causes fog?
Fog consists of myriads of tiny water droplets or ice crystals hanging in the air just above the ground. It is formed when the air is cold and the ground is warm, or vice versa. In both cases, a thick, shroud-like cloud of water vapor or ice particles appears and spreads across the surface.
4. Why doesn’t water burn?
Water is formed as a result of a chemical reaction where hydrogen is oxidized by oxygen and heat is produced. Because it has already surrendered its heat, water is incapable of burning under natural conditions.
3. Why do clocks run clockwise?
Before mechanical clocks were invented, people used sundials to tell time. Sundials first appeared in the Northern Hemisphere, where sun’s movement makes shadows move from left to right. Later on in history, mechanical timepieces inherited the dial setup from sundials
2. Why is a wheel round?
A round shape is perfect for rolling along flat surfaces. Because all points of a wheel’s rim are equidistant from its axis, the axis remains at the same height above the ground and the vehicle doesn’t jerk up and down as it moves along the road. If our roads’ surfaces were ridged, we would feel more comfortable driving cars with square-shaped wheels!
1. Why do we wear underwear?
Besides the feelings of comfort and confidence that underwear gives us, it also protects our private areas from infections and chafes. Historically, hygiene was the main reason to wear underwear. Clothes were very expensive, and people didn’t change their outfits very often. Today hygiene is also the most important reason to wear underwear.