How Come?

Why are hurricanes named after people, and in a certain order? ask Melissa Vallance and Kelli Day, students in Holtsville, NY.

While a tornado would have skipped to the next county and disappeared before you could call it “Ralph,” hurricanes take their sweet time building up their winds, moving towards coastlines and back out to sea at a stately pace. So it’s important to identify these big storms for pilots, ships, and people living in a hurricane’s path.

In the U.S. before the 1950s, hurricanes were identified by latitude and longitude, a system that became confusing when there was more than one tropical cyclone brewing at a time. In the early 50s, the U.S. decided to name storms using the Army/Navy phonetic alphabet, devised for World War II military communications: Able, Baker, Charlie, etc. So in 1952, the news reported on Hurricane Dog, Hurricane Easy, and Hurricane Fox. (If the tropical storm season had been busier, coast-dwellers might have been threatened by Hurricanes How, Item, Love, Sugar, Uncle, X-ray, and Zebra.)

Human beings have a long history of personifying nature (as in Thor, the Norse god of thunder), so using human names for big storms makes sense. Hurricanes that hit the West Indies in the 19th and early 20th centuries were named after saints. And in the 1940s, weather forecasters often gave hurricanes women’s names, like World War 2 fliers naming their fighter planes.

Read the rest of this entry »

How come your hands get all wrinkled after they’ve been in water? asks Kelsey Steck, a student in Holtsville, NY.

While nearly everyone gets pruny fingers after a long bath, their exact cause is still a mini scientific controversy.

Part of the explanation involves how skin responds to water. While skin is a good protective covering for our bones and organs, it isn’t waterproof. In fact, skin is nourished and plumped up by water, even absorbing it from the air around us.

The skin’s outer layer, the epidermis, is attached to the thicker layer underneath, called the dermis, but there is some “give” between the two. Hair follicles in the dermis pump out sebum, an oil that protects and lubricates the skin. But the undersides of fingers and toes (as well as palms and soles) don’t have hair, and don’t have as much protective oil.

Read the rest of this entry »

Why does a penny at the bottom of a glass of water sometimes look like it’s floating on the surface? asks a reader.

Tricks of light and water are all around us. Gaze at a goldfish through the curved wall of its bowl: The fish looks both bigger and at a different depth than it appears when we look down through the open top. And if the fish decides to hang out on the bottom of the bowl, you may see a fishy mirage, floating on the surface.

And then there’s the drinking-straw-in-the-glass illusion. Put a straight straw in a glass of water, and voila: Instant bendy straw. The fact that a straw appears bent or broken is caused by something that really is bent: light.

Light moving from thin air into solid glass slows (and the light wave bends) as it passes into this denser material. It bends again when it travels out of glass and into water. Reflecting off objects underwater, the light travels back through the water and glass, re-emerging in the open air. At each junction, it has bent a bit more. By the time it reaches your eyes, the light is seriously off course. So the part of an object that is submerged in water, like a drinking straw, appears to have moved seriously out of place.

Read the rest of this entry »

Why do things made of rubber bounce? asks Khiana Lowe, a student at Long Island Lutheran Middle and High School in Brookville, NY.

If you’ve ever tried dribbling a wooden ball, or attempted to shoot a piece of string across the room, you know there’s something different about rubber. Rubber, whether natural or manmade, is very elastic. An elastic material is one that can be stretched to several times its own length without breaking – and then snap back to its original size.

Bouncy is just another word for highly elastic. And rubber is very, very bouncy. Natural rubber is made of long, flexible chains of carbon atoms, connected here and there to hydrogen atoms, coiled up into a tangled mass. In plastic, another material whose molecules are arranged in long chains, the chains are rigid. But rubber’s chains can twist and flex. When a piece of rubber stretches, the molecular chains uncoil; when the rubber is released, the chains retract, curling back into place.

Read the rest of this entry »

Why do leaves change color in the fall? asks Patricia Brown, of New York City.

Autumn’s cool days are trimmed with deep blue skies and golden light, and brilliant leaves of yellow, orange and red. Leaves changing color in the fall are a tree’s way of preparing for long winter, rather like we put up storm windows and pull warm clothes and blankets out of storage.

In summer, the leaves on trees like pin oaks and sugar maples are green because they are chock-full of the green pigment chlorophyll.

Trees need sunlight to produce chlorophyll. In turn, chlorophyll uses sunlight’s energy to split water (H2O) into hydrogen and oxygen. Meanwhile, leaves also absorb carbon dioxide gas from the air. The end products of leaf chemistry: carbohydrates (homemade plant food for the tree), and oxygen, released into the air (the gas we need to breathe). The whole process is called photosynthesis.

Read the rest of this entry »

How does a boomerang return to the person who threw it? asks Rajendra Singh, of Jaipur, India.

Baseballs don’t. Footballs don’t. Even frisbees don’t. But boomerangs do–come back, that is.

If boomerangs were a new toy on the market–just invented–there would probably be a boomerang craze going on. Everyone would rush out and stand in long lines to be the first on the block to have one.

But in fact, boomerangs are very old. People were playing with the come-back toys thousands of years ago.

Read the rest of this entry »