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. 
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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. 
Dr. Hugh Willoughby, of Florida International University, was one of the first meteorologists to ever fly into the eye of a hurricane. Now the job is done by the Hurricane Hunters—a team of pilots, navigators and meteorologists who fly into these dangerous storms to help keep us safe. Here’s what I learned when I interviewed Hugh Willoughby: What is a hurricane eye? Hurricanes are circular storms so the wind blows around in a circle. The eye is the center of a hurricane. If a circular storm doesn’t have an eye, it is not a hurricane—it’s a tropical storm. The eye is surrounded by a ring of clouds called the eyewall. Within the eye, there is a calm area that is cloudless all the way up to space. The winds are strongest just at the inner edge of the eyewall, which is composed of violent thunderstorms with strong updrafts and downdrafts. The hurricane pinwheels out from the eyewall as spiral bands of wind and rain, which stretch for miles. When a hurricane’s eye passes over land, the storm suddenly stops and the sun comes out. But the relief is short-lived as the other side of the storm soon slams into the area. How do Hurricane Hunters help us? Hurricane Hunters fly into the eye of hurricanes that are heading towards our shores to help predict where the storm will make landfall. On every mission they must find the center of the storm at least twice and at most four times over a period of several hours because the change in position of the center of the eye tells us the direction the storm is moving and how fast it is moving. They also drop packages called dropsondes that contain measuring instruments for air pressure, humidity, and wind speed at the eyewall. These measurements tell us the destructive power of the storm or its “category.” During a hurricane season (from June 1 to November 30) the Hurricane Hunters and their fleet of ten airplanes can get data on three storms, twice a day. So flying into a hurricane’s eye is pretty routine for them. Is it dangerous? The planes can easily handle changes in air pressure and wind speeds that create “bumps” and it can be pretty bumpy going through the eyewall. But, in more than sixty years there have been only four accidents. All on board agree that the view of the eyewall from inside the eye is worth it! The plane has transported them inside nature’s most magnificent amphitheater. (c) Vicki Cobb 2014 Harvey and Irma have alerted everyone to the dangers of a hurricane. We can predict the course of a hurricane by flying into a hurricane and repeatedly measuring wind speed, humidity, air pressure, and temperature. Here's a video that will give you a taste of what it looks like as you approach an eye wall. It is filmed from a plane penetrating Hurricane Katrina. 
 MLA 8 Citation Cobb, Vicki. "Flying into the Eye of a Storm." Nonfiction Minute, iNK Think Tank, 18 Sept. 2017, www.nonfictionminute.org/the-nonfiction-minute/ flying-into-the-eye-of-a-storm. |
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For Vicki Cobb's BLOG (nonfiction book reviews, info on education, more), click here: Vicki's Blog *NEWSFLASH *
The NCSS-CBC Notable Social Studies Committee is pleased to inform you that 30 People Who Changed the World has been selected for Notable Social Studies Trade Books for Young People 2018, a cooperative project of the National Council for the Social Studies (NCSS) & the Children’s Book Council Categories
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