Science through the lens
Which lunch food has a shape that resembles a falling raindrop?
b. potato chip
c. hot dog
d. hamburger bun
e. all of the above
f. none of the above
If you chose (f), you’re like most people who think raindrops are shaped like tears.
If you chose (e), you’re probably just hungry.
In either case you’re wrong.
That leaves us with lunch. Let’s start from the top.
Choice (a), orange, is a sphere. Water droplets are spherical because water is cohesive, meaning it sticks to itself. The “skin” that holds the drop together is surface tension and the reason insects can walk on water.
If you chose (a), you made a logical choice based on the properties of water, but you are wrong. Notice that you were not asked to identify the shape of a raindrop sitting on a leaf. You were asked to identify the shape of a falling raindrop. (Always read questions carefully!)
Moving down the list to (b), we encounter the potato chip. Potato chips come in many shapes, ranging from relatively flat to completely crumpled. Have you ever seen a raindrop that looks even a little bit like a potato chip? If you chose (b) you are wrong, but have a good sense of humor.
Choice (c), hot dog, is an interesting option. Could a spherical drop of water morph into the cylindrical shape of a hot dog? After all, a hot dog is a cylinder with a hemisphere (half sphere) on each end. Could a water droplet in free fall separate itself into two hemispheres with a long drip of water in between? Although this is an imaginative idea, the laws of physics make it impossible.
Choice (d), hamburger bun, is the only remaining choice, and is the correct answer. Here’s why:
A raindrop is acted upon by three forces: gravity, buoyancy, and drag. Gravity is the force that pulls the drop toward the earth, while buoyancy of the surrounding air pushes it upward and keeps it from falling. When the force of gravity is greater than the force of buoyancy, the raindrop falls. The air around it creates drag, slowing the drop down to its maximum speed. In the process, the sphere is distorted into a shape that resembles a hamburger bun.
Got it? Now, you may go to lunch.
Bugs bite, drink blood, and rob food from gardens and fields. They can even kill plants, animals, and, occasionally, people. Is bugging a crime? In her latest book, Bug Shots, Alexandra Siy compiles "rap sheets" on several of the major categories of bugs and takes a very close look at some of the types of insects in an engaging text. For more information, click here.
Alex Siy is a member of iNK's Authors on Call and is available for classroom programs through Field Trip Zoom, a terrific technology that requires only a computer, wifi, and a webcam. Click here to find out more.
MLA 8 Citation
Siy, Alexandra. "The Race for the Sky." Nonfiction Minute, iNK Think Tank, 7 Dec. 2017, www.nonfictionminute.org/ A-Raindrop-Quiz.
The Running Encyclopedia
The Renaissance began in Europe in the 15th century and marked the change from the medieval period to the modern world. Towering figures such as Michelangelo, Galileo, and especially Leonardo da Vinci were known as Renaissance men because of their talents and lasting achievements in several important areas of knowledge. They were also accomplished musicians, public speakers, athletes, poets, and so forth. And they were expected to do all this stuff without breaking a sweat.
You could give the same title to an ancient Egyptian named Imhotep, who lived about 2600 BCE. He was the vizier, the most important government official, during the reign of Pharaoh Djoser. He served as the high priest of the god Ra and was an expert astronomer.
Imhotep designed and oversaw the building of the first major pyramid in Egypt. Located at Saqqara, at the time it was the world’s tallest structure. He innovated the use of stones rather than mud bricks to build it, and it was that added strength that enabled the pyramid to rise so high. He is also credited with the invention of several devices that facilitated the construction.
Many people believe that Imhotep, rather than the Greek Hippocrates who lived more than 2,000 years later, is the real “Father of Medicine.” In an era when most physicians relied on magic spells and appeals to the gods, Imhotep prescribed dozens of effective down-to-earth treatments for illnesses and injuries.
He is credited with ending a seven-year famine in Egypt. He advised the pharaoh to make sacrifices to Khnum, the god of the annual flooding of the Nile River, and thereby provide desperately needed water to farmers. On a more practical level, he invented an improved irrigation system to carry water to the crops even if the river level was abnormally low.
In addition to these accomplishments, an inscription at the base of one of his statues notes that he was “Chief Carpenter, Chief Sculptor, and Maker of Vases in Chief.” In his little spare time, he wrote poetry and dispensed philosophical advice.
Imhotep can also boast of two accomplishments that eluded even Leonardo da Vinci. He was deified after his death and worshipped for many centuries, an honor accorded to hardly anyone besides the pharaohs. And today the comic book community gives him the credit for founding S.H.I.E.L.D., the Marvel Comics espionage and crime-fighting agency that became the basis for blockbuster movies such as Iron Man, Thor, and Captain America.
Jim Whiting has written a book on another great Egyptian leader -- Ramses the Great who lived about 1350 years after Imhotep. He fully lived up to the "Great" part of his name. His reign lasted for 67 years, the second longest in Egypt’s 3,000-year history. He had dozens of wives and more than 100 children, outliving many of them. He was a military leader who expanded the borders of his country. That resulted in decades of peace and prosperity for his people. He ordered huge statues of himself to be erected all over Egypt. For more information, click here.
MLA 8 Citation
Whiting, Jim. "A Renaissance Man - 4,000 Years before the Renaissance."
Nonfiction Minute`, iNK Think Tank, 8 Feb. 2018,
For Vicki Cobb's BLOG (nonfiction book reviews, info on education, more), click here: Vicki's Blog
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