 A land surveyor sends a heliograph to his partner more than 100 years ago. He must have been fluent in Morse Code How do you know it’s the holiday season? There are lights everywhere sending that message. But that’s not the only kind of message light can send. A little more than 100 years ago when a telegraph began to become popular, people sent wireless messages called heliographs. They were made of flashes of light in Morse code (the same pattern of short and long as used in telegraphs) by reflecting the sun’s rays with a mirror. When the mirror was at a particular angle to the sun, it reflected a flash of bright light to observer miles away.  Note where the red light from the bulb emerges on the opposite side. Some internally reflected light is emerging from a ridge in the glass. Photo by Alexandra Siy Maybe there’s another way to send light. Put a holiday light on one rim of a heavy glass measuring cup or dish. See where the light emerges on the rim on the opposite side. Move the light back and forth and watch what happens on the other side. The light travels down the side, and bends to go across the bottom and up the other side, but if you look at the cup sideways you can’t see the beam. Light stays inside the glass as it travels from rim to rim. Could we make something like a wire from glass that can transmit light? Absolutely! An optical fiber is a flexible, transparent fiber made of glass or plastic that acts as a wire for light. Imagine a beam of light entering a fiber at exactly the right angle to bounce off the inside wall of the fiber where it meets the air. It is then reflected at exactly the same angle to bounce off the opposite wall making a zig-zag path until it reaches the end of the fiber. This internally reflected light stays inside the glass fiber as it travels at the speed of light. HUGE quantities of all kinds of information—words, pictures, music, and videos—can now be sent through optical fibers, much more than through wires. A modern network with copper wiring can handle about 3,000 telephone calls at the same time, while a similar system using fiber optics can carry more than 30,000! So when you hit “send,” know that your holiday message is a blinking beam of light, bouncing off the inside walls of a glass fiber on its speedy journey to friends and family. How ‘bout that!  Fiber optics can be made into holiday decorations. Note the bright light emerging from the ends of the fibers.  Want to know more about optics? Have a look at Vicki Cobb's book Light Action! She co-authored it with her son, Josh, who is an optical engineer and her other son, Theo, drew the pictures. It's full of experiments that let you use optics to: -Bend light around corners - Stop time with a pair of sunglasses - Capture light on a silver tray - Magnify pictures with an ice cube - Pour light into your palm - Project a big-screen image from your small TV - Fool a doorbell with a bike reflector! For more information, go here. Vicki 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 Cobb, Vicki. "What Can You Learn from a Holiday Light and a Glass Cup?" Nonfiction Minute, iNK Think Tank, 14 Dec. 2017, www.nonfictionminute.org/ What-Can-You-Learn-from-a-Holiday-Light-and-a-Glass-Cup. 
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Polar bears are built to withstand some of the coldest temperatures on the planet. Their brown and black bear cousins avoid the winter cold by digging dens and sleeping. But, except for pregnant females, polar bears spend the arctic winter outside where temperatures could be -40° F (which equals-40 °C) and windy. That’s too cold for humans. You could go outside, but only for only a few minutes with every part of your body completely covered. And if you didn’t wear goggles, your eyelashes would freeze and break off if you touched them. Polar bears are warm-blooded like us with a body temperature of about 98°F/37°C. But they are invisible to night-vision goggles that pick up the infrared rays that warm-blooded creatures, including humans, give off. Why? Nature has given polar bears enough insulation to prevent body heat from escaping. They are toasty warm and comfortable in the frigid arctic. Their heat insulation is in several layers. Under their skin, there is a 4-inch (21.5 cm) layer of fat. Next to the skin is a dense layer of woolly fur that also keeps heat in. The fur you see is a thick layer of long, colorless guard hairs that shed water quickly after a swim. They are stiff and transparent and hollow. In the arctic sunlight, the hairs act like mirrors and reflect white light, which acts as camouflage against the snow so the bears are not seen by their prey. Polar bear skin is actually black, so that it can absorb the invisible warm infrared rays of the sun and the bear’s own body heat, both of which are reflected back by the guard hairs. Most warm-blooded animals raise their body temperatures through exercise. Polar bears hunt seals, which they don’t often chase. They prefer to sit at the edge of an ice floe and wait for dinner to arrive. At best, they’ll lumber after a seal at four and a half miles (7.25 km) an hour, raising their body heat to 100°F (38°C). When that happens, they go for a swim to cool off. Cold won’t kill off the polar bears, but global warming can. As polar ice disappears, so does the hunting ground for seals. Not so cool!  The polar bear is the largest land carnivore. Its long non-retractable claws help it get a grip on the icy surface it prowls for prey. Wikimedia Commons  Close up, the polar bear guard hairs are transparent. This allows the infra-red light (heat) from the sun to pass through them to be absorbed by the black skin under the hairs. The hairs also act like mirrors , reflecting back to the skin any infra-red radiation escaping from the bears body so it can be reabsorbed. Thus, the insulation is just about perfect with no infra-red radiation escaping. The hairs are also coated with oil so they drain quickly after a swim.  The polar bears’ white appearance serves as ideal camouflage in a snow-covered environment. Art by Barbara Lavelle from This Place is Cold by Vicki Cobb.  Vicki Cobb's This Place Is Cold shows how the latitude of Alaska affects the lives of the plants, animals and people who live there. It is gloriously illustrated by Barbara Lavallee, a long-time Alaskan resident and artist. Vicki is a member of Authors on Call—she can visit your classroom with interactive videoconferencing: Read more about her here. MLA 8 Citation Cobb, Vicki. "The Way Polar Bears Keep Warm Is Cool." Nonfiction Minute, iNK Think Tank, 29 Nov. 2017, www.nonfictionminute.org/The-Way-Polar-Bears-Keep-Warm-Is-Cool.  
Are your two nostrils exactly the same size? Don’t struggle to find out by looking in a small mirror. Put your nose right above the mirror and breathe down on it. You will see two circles of moisture as the warm moist air from your nose condenses into water when it hits the cool mirror surface. One circle will be a LOT larger than the other. You might conclude that yes, one nostril is bigger than the other; that you will have to live with being lopsided. But wait! I mean wait an hour or so and do it again. Surprise! This time the small nostril is now the BIG one! The larger nostril is dominant and takes in more of the air. You can do scientific study of your nose and see just how long each nostril dominates. Perhaps if you check often enough, you’ll discover a time when the two circles will be about the same size. This will be the moment of the changing of the nostrils. Of course, you have to do this study when you don’t have a stuffy nose. What’s behind this? It seems that your nostrils are on an automatic timer from your brain so that they take turns being dominant. It’s very interesting. But I’m not sure if it is important. Not many people know about this. But your dentist might. A dentist is always looking at peoples’ nostrils. See if your dentist knows about this. He or she might even know why this happens. This just might be a medical mystery worth investigating. And you might be just the one to do it.
 Vicki Cobb ‘s “Discover Your Senses” series of books are available through the iTunes store. She begins by asking: “Know how to stop smelling? Hold your nose.” Also, check your library for copies. I mean wait an hour or so and do it again. Vicki 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 Cobb, Vicki. "The Mystery of the Alternating Nostrils." Nonfiction Minute, iNK Think Tank, 21 Nov. 2017, www.nonfictionminute.org/the-mystery-of-the-alternating-nostrils.  
How well do you handle spicy food? Do you find food with a “kick” eye-watering and difficult to swallow? Or are you a real “fire eater;” nothing can be too hot?
A scientist, named Wilbur Scoville, figured out how to rank spicy food for hotness in 1912. The “heat” from peppers comes from a chemical called capsaicin (cap-say-sin). Pure capsaicin registers 16 million heat units on the Scoville scale. Zero is a sweet green, red or yellow pepper. A fresh, green Jalapeño (ha-la-pen-yo) is rated 2,500-8,000 units, a lot less hot than pure capsaicin. The fact is that you don’t “taste” the heat. The sensation of heat comes from nerve endings in your tongue that respond to pain. Of course, these nerve endings are not just in your tongue. They are all over your body. So a good scientific question is: Can you “taste” hot sauce with, say, your wrist? Check it out. Rub the inside of your wrist with a cut Jalapeño pepper or some hot sauce. Wait a few minutes. Feel the burn? Rinse off your wrist well with cool water. Your tongue, of course, is much more sensitive than your wrist to many chemicals because it is always wet. Capsaicin, like a lot of other chemicals dissolves in water and reaches those nerve endings more quickly. Another liquid that triggers your pain nerves in your tongue is soda. The carbon dioxide in the bubbles reacts with an enzyme in your mouth to form a weak chemical called carbonic acid. This acid fires the pain nerve endings in your tongue giving soda its “bite.” How well can you tolerate this pain? Stick your tongue into a freshly opened glass of soda and hold it there. See how long you can keep it in the drink. One minute? Two minutes? Most people can’t last a minute. But maybe you’re tougher than that. Some Mexican parents give their kids mixtures of sugar and red chili powder when they’re little to build up their tolerance for spicy foods. Do you think that people who love spicy food could also be champions at keeping their tongues immersed in soda? Design an experiment to find out at your next party. Hot Stuff from Vicki Cobb on Vimeo. atonguelashing from Vicki Cobb on Vimeo. 
These videos were made from Vicki Cobb’s book We Dare You! She invites you to join her video project and make your own videos from her book and post them on the www.wedareyouvideos.com website. Vicki Cobb 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
Cobb, Vicki. "Some Painful Truth." Nonfiction Minute, iNK Think Tank, 17 Oct. 2017, www.nonfictionminute.org/the-nonfiction-minute/some-painful-truth. 
Ever taste a stale potato chip? If not, here’s how to make one:
Take a close look at an opened bag of potato chips. It is foil-lined to make it light proof. An unopened bag is very puffy because it is filled with a gas. This puffiness protects the chips from breaking. But the gas in the bag is not air, which is a mixture of about 20% oxygen and 79% nitrogen. It is air without the oxygen, so it’s mostly nitrogen. You can prove this. Oxygen is needed for fire to burn. If the air around a flame is flooded with nitrogen, the flame goes out. So you can use the gas in a bag of potato chips to put out a candle. Here’s how:
Now go educate some grown-up.
 Vicki Cobb’s best known book is Science Experiments You Can Eat. This is the new third revision published in 2016. Vicki Cobb 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 Cobb, Vicki. "How to Extinguish a Fire with a Bag of Potato Chips." Nonfiction Minute, iNK Think Tank, 2 Oct. 2017, www.nonfictionminute.org/the-nonfiction-minute/how-to-extinguish-a-fire-with-a-bag-of-potato-chips. |
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