Category: Cobb Vicki

Flying into the Eye of a Storm

9/20/2022

Vicki Cobb

The Master Chef of Kids’ Hands-On Science

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.

When you hear about a Category "3" hurricane, or any other category number, the Saffir-Simpson Scale tells you just what that number means.

Look at the amazing number of instruments contained in a Dropsonde.

Vicki Cobb's latest book, How Could We Harness a Hurricane? shows how the scientific understanding of air, water and energy come together to form hurricanes. It includes lots of hands-on activities that you can do. Engineers look at science and try and figure out ways the steer a hurricane away from populated areas or weaken them. There are lots of questions in the book and some of them don't have answers, yet.

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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Earth's Emergency Heat Valve: The Hurricane

6/2/2022

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Vicki Cobb
The Master Chef of Kids' Hands-on Science

Earth has a problem. The sun creates hot spots over land, in the air and in the water. That’s why there are winds, weather, and currents in the ocean as Earth tries to even out the heat, moving warmer masses of air and water to cooler areas.

During hurricane season ( from June 1-November 30), only 10 or 11 of the 80 tropical disturbances off the west coast of Africa (where most of our hurricanes originate) become large enough storms to be given a name. Only two or three of them hit the United States. They are not frequent but they are massive wind storms that can destroy life and property.

Do they do anything good at all? As far as the Earth is concerned, these largest of all storms are a safety valve to rapidly move heat that has been accumulating in the oceans up to the stratosphere (from 7 to 31 miles above the Earth’s surface). From there it will be transported through the air to over the North Pole. It’s the way Earth stops a fever.

Once a hurricane forms, it must have an ocean surface that is at least 80°F to keep moving and to grow. Under the storm, huge amounts of warm water become water vapor. Warm moist air rapidly rises through the spinning winds of the hurricane, up to the stratosphere. When moist air reaches the frigid (-70°F) stratosphere the water vapor quickly condenses to liquid water (rain) releasing its heat. This heat makes surrounding air molecules move faster forming winds.

How do hurricanes cool off the oceans? How do they move the heat? Here’s a clue: Wet your finger and wave it in the air. How does it feel? Pretty cool, I bet! That’s because the heat from your finger changes liquid water into water vapor (a gas) as your finger dries. Water vapor molecules store this extra heat. They rise because they are lighter than other air molecules.

So, a hurricane is a heat engine that moves water vapor from the ocean’s surface high enough to condense back into liquid water and release heat safely to the stratosphere forming rivers of wind that move it to the poles.

Scientists predict that global warming will increase the number and the power of the hurricanes as the ocean surfaces become increasingly warmer during our summers.

This diagram of the anatomy of a hurricane shows the direction of the winds. The blue represents cold air descending while the pink shows warm moist air rising. The outflow surface clouds form as water condenses into a "table-top" cloud, releasing heat that becomes wind. Kelvinsong via Wikimedia

Hurricane Isabel (2003) as seen from orbit during Expedition 7 of the International Space Station. The eye, eyewall, and surrounding rainbands, all characteristics of hurricanes, are clearly visible in this view from space. Image courtesy of Mike Trenchard, Earth Sciences & Image Analysis Laboratory, NASA Johnson Space Center

Vicki Cobb's How Could We Harness a Hurricane? offers questions and provides new points of view that may just change peoples' thinking by showing young readers the work scientists and engineers are doing to avoid future disasters. The book includes hands-on experiments that make science fun, be it at home or in the classroom. Here's a link to the book' s Trailer.

How Could We Harness a Hurricane was named a 2018 Best STEM Book K-12 by the National Science Teachers Association and the Children's Book Council.

Vicki is a member of iNK's Authors on Call so you can invite her to your classroom via iNK's videoconferening Zoom Room. Click here to find out more:

MLA 8 Citation
Cobb, Vicki. "Earth's Emergency Heat Valve: The Hurricane." Nonfiction Minute,
iNK Think Tank, 24 Apr. 2018, www.nonfictionminute.org/
the-nonfiction-minute/Earths-Emergency-Heat-Valve-The-Hurricane.

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The Battle Hymn of the Chicken Pox Troopers

5/23/2022

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Vicki Cobb
The Master Chef of Kids’ Hands-on Science

How does a virus cause a disease? A virus is not a complete living thing. It is like a free-floating nucleus of cell. It doesn’t “grow” but under certain conditions it can make a copy of itself or reproduce. It invades the cells of other living things to use the internal structure of the host cells to reproduce. At a certain point, the number of new viruses in a cell is so large that the cell ruptures and dies, spilling out newly made viruses to continue the invasion to other uninfected cells.

One virus we understand very well is chicken pox. Chicken pox is a very contagious disease that enters the body through the air and affects mostly children. When I was young almost every kid got chicken pox but, since 1995, there has been a vaccine, which makes you immune and protects the spread of the disease to others. Is there another way to explain how this virus works? Suppose I imagine a virus could think, which it can’t. But, imagination gives me the freedom to think differently.

So I wrote a poem about an army of chicken pox viruses as they are about to attack a human being, maybe you, my reader. A “battle hymm” is a chant or a song to rally the troups just before an attack.

The Battle Hymn of the Chicken Pox Troopers

Charge forward, fellow viruses!
Invade a cell or two
Then let us join together
And make a chicken pox on you.

Let cells try to fight us
No matter what they do
Red spots of our graffiti
Make a chicken pox on you

We make the top skin separate
And fill the space with goo,
Small, itchy blisters are a stage
Of chicken pox on you.

And when the blisters break, my friend
You think perhaps we’re through
But no. Now there is a scab
For each chicken pox on you

Scratch a scab so it comes off
Baring skin that’s raw and new,
A scar forever marks the spot
Of that chicken pox on you.

The source? Chicken with fowl pox

To the battle, fellow viruses!
We’re more noteworthy than flu
They just make you feel sick
We make our chicken pox on you!

Meet your personal superheroes - your body's cells Superhero cells rally together to battle common childhood ailments in this series in which Vicki Cobb explains how your amazing human body heals itself and fights off intruders. Here's her book on yet another virus: Your Body Battles a Cold.

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Banging on the Ear Drum

5/16/2022

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Vicki Cobb

The Master Chef of kids’ hands-on science

Ever notice people wearing headsets to keep out noise? Check out the workers on the tarmac of airports, or gardeners with their leaf blowers, or road workers breaking up blacktop with a pneumatic drill. They wear these headsets to protect their ears from damage caused by persistent loud noise.

Loudness is measured in decibels, dB for short. Complete silence is 0 dB, a whisper is 10 dB, normal conversation is 60 dB or about 10,000 times louder than a whisper. A lawnmower is 90 dB, about 1,000 times louder than a conversation and a jet engine is 120 dB about 1,000,000 times louder than a conversation. Anything over 85 dB does damage to our ears. That’s because sound traveling through air is a force beating against delicate eardrums. Yes, rock concerts damage ears.

Performing musicians often have tiny earpieces in their ears. This way the sound engineers can send them the sounds of their own voices or instruments, so that they can hear themselves over the other musicians. Those pieces are not for protection. So the dB level of rock concerts can affect those musicians’ hearing. There is even a name for it: Noise Induced Hearing Loss or NIHL. Rock musicians are the top profession to suffer NIHL later in life.

But there is a new threat to hearing loss—the earbuds people use to listen to music from their electronic devices. They are fine if you keep the volume down. But if you’re hooked on loudness that invades all your senses so that you can’t “hear yourself think” and you listen for several hours a day, you’ll pay the price down the road.

Your ability to hear high tones is the first to go. Here’s a quick and easy hearing test you can use on yourself and your family: Turn on the TV and hit the “mute” button or turn the volume all the way down. Lean over the back of the set and listen for a very soft, high-pitched whine. If you can hear it, you are listening to the highest sound the human ear can hear. (Dogs, of course, can hear much higher sounds, hence the dog whistle, which people can’t hear but dogs can.) Walk away from the set to find the distance when you can no longer hear it. Do the same test with your parents. Bet your hearing is better than theirs.

Try listening to some old-fashioned, melodic, soft popular music that came before rock and roll. You just might like it.

Listening to her own soft music, or just blocking out your loud music? Either way, her hearing is better than yours. Photo by Alexandra Siy

From School Library Journal--
"Fun!" comes through loud and clear in this energetic exploration of hearing and auditory perception. Cobb gets the anatomy lesson out of the way, then moves on to a series of simple activities to help kids experiment with their own sense of hearing. Students investigate sound conduction, perception of pitch, echolocation, and range of hearing by doing such things as sticking fingers in their ears while they talk."
Available for download at the i-Tunes store -- click here.

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. "Banging on the Ear Drum." Nonfiction Minute, iNK Think Tank, 30
Apr. 2018, www.nonfictionminute.org/the-nonfiction-minute/Banging-on-the-Ear-Drum.

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Why You Can’t Defrost a Salad…Yet

5/2/2022

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Vicki Cobb
The Master Chef of Kids' Hands-on Science

At left in the back is a fresh spinach leaf that has been treated with trehalose, frozen and defrosted.. The droopy one has been frozen and defrosted without trehalose. It's what is giving us hope that we may soon be able to defrost a salad.

When it comes to preserving a fresh taste in food to be eaten at some later time, nothing beats freezing it. That was the discovery made by Clarence Birdseye in 1924. He had been working in northern Canada and noticed that fish caught by the native Canadian Inuits froze almost instantly in the frigid winter air. It was just as delicious when cooked and eaten months later as it was on the day it was fresh. Birdseye figured that if food was frozen quickly at very cold temperatures, large ice crystals couldn’t form to damage the food and make it mushy. His flash-freezing process made him very rich.

The problem isn’t so much the freezing of food as what happens when it’s defrosted. See for yourself. Stick a stalk of celery in your freezer. The next day defrost it. Want to eat it? Compare it to a fresh unfrozen stalk. The perky structure of fresh celery is destroyed by ice. Water has the very unusual property of expanding and taking up more space when it changes into ice than when in a liquid state. That’s why ice cubes float and frozen unopened soda cans bulge.   Expanding ice crystals destroy the cell walls of plants. Quickly freezing fresh food keeps the ice crystals smaller than slower freezing, but they are still large enough to destroy the cell walls of delicate vegetables like spinach or lettuce. But if you defrost frozen spinach from the supermarket it is beyond limp. So a salad you can defrost and serve as if it were fresh has seemed like an impossible dream.

Federico Gomez, a Swedish scientist, is working to change this. Like Birdseye he took a close look at nature, specifically at plants that stay alive in very cold climates. He discovered that they contain a sugar called trehalose (tree-HAL-ose) that works like a natural antifreeze. Could he find a way to get trehalose into spinach leaves? If so, would the trehalose protect the structure of the spinach and keep it crisp after defrosting? This picture shows the results. The leaf on the left was treated with trehalose. The one on the right was untreated. He froze and defrosted both. The treated leaf is as crisp as if it had never been frozen!

Just because there is success in a lab doesn’t mean a defrosted salad will show up on your dinner plate any time soon. But these results are enough to keep the research going.

Move over Clarence Birdseye!

This is a nice fresh, crisp piece of celery...

...and this is the same piece of celery after being frozen and then defrosted. Yuk!

Cobb has revised her classic book, Science Experiments You Can Eat. While doing her research, she came across this work of Frederico Gomez. She bought trehalose on line and soaked some slices of parsnip and zucchini in a trehalose solution, hoping that the sugar would be absorbed by the plant cells. But when she froze them and defrosted them, it didn't work. Dr. Gomez got the sugar inside the plant cells by removing some water from between the cells in a vacuum chamber, soaking the leaves in a trehalose solution (which moved the sugar into the spaces outside the cells) and then exposing the leaves with a mild electric shock to get the sugar through the cell walls. Vicki didn't have the equipment to do all this but she tried anyway. The book was 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. "Why You Can't Defrost a Salad...Yet." Nonfiction Minute, iNK Think
Tank, 11 01 2018, www.nonfictionminute.org/the-nonfiction-minute/
Why-You-Can't-Defrost-a-Salad-Yet.

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Flying into the Eye of a Storm

Earth's Emergency Heat Valve: The Hurricane

The Battle Hymn of the Chicken Pox Troopers

Banging on the Ear Drum

Why You Can’t Defrost a Salad…Yet

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