Ask a Science Teacher: 250 Answers to Questions You've Always Had about How Everyday Stuff Really Works - Softcover

Scheckel, Larry

Softcover

ISBN 10: 1615190872 ISBN 13: 9781615190874

Verlag: The Experiment, 2013

Inhaltsangabe

Fun and fascinating science is everywhere, and it’s a cinch to learn—just ask a science teacher!

We’ve all grown so used to living in a world filled with wonders that we sometimes forget to wonder about them: What creates the wind? Do fish sleep? Why do we blink? These are common phenomena, but it’s a rare person who really knows the answers—do you?

All too often, the explanations remain shrouded in mystery—or behind a haze of technical language. For those of us who should have raised our hands in science class but didn’t, Larry Scheckel comes to the rescue. An award-winning science teacher and longtime columnist for his local newspaper, Scheckel is a master explainer with a trove of knowledge. Just ask the students and devoted readers who have spent years trying to stump him!

In Ask a Science Teacher, Scheckel collects 250 of his favorite Q&As. Like the best teachers, he writes so that kids can understand, but he doesn’t water things down— he’ll satisfy even the most inquisitive minds. Topics include:

•The Human Body
•Earth Science
•Astronomy
•Chemistry Physics
•Technology
•Zoology
•Music and conundrums that don’t fit into any category

With refreshingly uncomplicated explanations, Ask a Science Teacher is sure to resolve the everyday mysteries you’ve always wondered about. You’ll learn how planes really fly, why the Earth is round, how microwaves heat food, and much more—before you know it, all your friends will be asking you!

Über diesen Titel

Über die Autorin bzw. den Autor

Larry Scheckel taught high school-level physics and aerospace science for over 38 years. He was named Tomah (Wisconsin) Teacher of the Year three times, and Presidential Awardee at the state level for six years. Scheckel has authored articles for The Science Teacher magazine and The Physics Teacher magazine, and for a number of years has answered science-related questions in the twice-weekly Tomah Times, out of which this book grew.

Scheckel has been a Science Olympiad coach, robotics mentor, organized star gazing sessions, and given orientation flights to students, and he has given presentations to thousands of adults and students in such venues as Children's Museums, Boys and Girls Clubs, Rotary, and conventions.He lives with his wife in Tomah, Wisconsin.

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ASK A SCIENCE TEACHER

250 Answers to Questions You've Always Had About How Everyday Stuff Really Works

By Larry Scheckel

The Experiment, LLC

Copyright © 2013 Larry Scheckel
All rights reserved.

ISBN: 978-1-61519-087-4

Contents

Preface, xvii, 
Chapter 1: The Magnificent Human Body, 1, 
Chapter 2: Wonders of Our Sea and Land, 75, 
Chapter 3: Science in the Sky, 105, 
Chapter 4: Technology, 147, 
Chapter 5: Stuff I Always Wondered About, 197, 
Chapter 6: Captivating Chemistry, 231, 
Chapter 7: The Strange World of the Atom, 259, 
Chapter 8: Science Through the Ages, 285, 
Chapter 9: Plants, Animals, and Other Living Things, 297, 
Chapter 10: Sound and Music, 323, 
Chapter 11: At the Fringes of Science, 333, 
Acknowledgments, 347, 
About the Author, 348, 

CHAPTER 1

TheMagnificentHuman Body

1. How many cells are in your body?

* There is no real consensus on the number of cells in the humanbody. Estimates put the number between ten trillion and one hundredtrillion. A trillion is a million million—it's a word that crops upwhen we talk about the size of our national debt! The number of cellsdepends on the size of the person: bigger person, more cells. Also, thenumber of cells in our body keeps changing as old cells die and new onesform.

Cells are so small that most can only be seen through a microscope.Every cell is made from an already existing cell. Each cell in the bodybehaves like a little factory and has two major components, the cytoplasmand the nucleus. The cytoplasm contains the structures that consumeand transform energy and perform many of the cell's specializedfunctions, including storing and transporting cellular materials, breakingdown waste, and producing and processing proteins. The nucleus isthe control center and contains the genetic information that allows cellsto reproduce. The mitochondrion (plural mitochondria) in the cell is thefactory where food and oxygen combine to make energy. Human cellsand other animal cells have a membrane that holds the contents together.This membrane is thin, allowing nutrients to pass in and wasteproducts to pass out. Food is the energy the cell needs. Each cell needsoxygen to burn (metabolize) the nutrients released from food.

The body has some cells that do not experience cell division. And redblood cells and outer skin cells have cytoplasm but do not have a nucleus.

In the cell, the process is called respiration. Oxygen breaks down thefood into small pieces. The oxidizing of the food molecules is turned intocarbon dioxide and water. Water makes up about two-thirds of theweight of the cell. The energy released is used for all the activities of thecell. The cell membrane has receptors that allow the cell to identify surroundingcells. Different kinds of cells release different chemicals, eachof which causes certain other types of nearby cells to react in certainways. Within each of these different cells are found twenty differenttypes of organelles, or structures.

Slightly over two hundred different kinds of cells make up the humanbody. The shape and size of each type of cell is determined by its function.Muscle cells come in many different forms and have many differentfunctions. Blood cells are unattached and move freely through thebloodstream. Skin cells divide and reproduce quickly. Some cells in thepancreas produce insulin, others produce pancreatic juice for digestion.Mucus is produced in cells in the lining of the lung. Our lungs also containalveolar cells that are responsible for taking in gas from the blood.The cells that line the intestine have extended cell membranes to increasethe surface area, helping them absorb more food. Cells in theheart have a large number of mitochondria to help them process a lot ofenergy, because they have to work very hard.

Nerve cells generate and conduct electrical impulses; for the mostpart, they do not divide. Each nerve cell has a specific place in our nervoussystem. Nerve cells outside of the brain are very long and have thetask of passing signals between the brain and the rest of the body, allowingus to move our muscles and sense the world around us. The rest ofour nerve cells—about one hundred billion of our body's cells—are braincells.

Brain cells are the most important cells in our bodies. It is our brainthat defines who we are. Brain cells in children under five do have theability to reproduce, to some extent. However, we are naturally losingbrain cells all the time. The best estimate of normal brain cell loss is putat nine thousand per day. That may seem like a large number, but rememberthat the brain has 100 billion cells, so a nine-thousand-cell lossper day is not that great. Inhalants, such as glue, gasoline, and paintthinner, cause brain cell loss at thirty times the normal rate. Excessivealcohol use is a big contributor to brain cell damage.

Cells that all do the same job make up tissue, such as bone, skin, ormuscle. Groups of different types of cells make up the organs of thebody. Different organs grouped together form a system, such as the digestivesystem or the circulatory system. All the systems working togethermake up a healthy human body.

Cells live, of course, but cells also die. Liver cells last about a year andhalf. Red blood cells live for 120 days. Skin cells are good for 30 days.White blood cells survive for thirteen days. And it turns out that thegreat majority of cells in the human body are bacterial cells, and mostare beneficial. It is hard to believe that the average adult loses close to100 million cells every minute. The good news is that the body, throughcell division, is replacing those lost 100 million cells every minute. Andin any case, even 100 million cells is only a small fraction of the trillionsof cells that make up our bodies.

2. Why do the young and the elderlyget sick more easily?

* Babies get sick more often than older children or adults becausetheir immune systems are not fully developed and functioning atfull capacity. The common cold, which is an infection of the respiratorysystem caused by a virus, is the most frequent malady. Doctors say thatnormal, healthy babies get up to about seven colds before they reachtheir first birthday. Another common affliction is the flu, caused by adifferent family of viruses, which bring on high fever, chills, fatigue, andsometimes digestive symptoms like vomiting and diarrhea, in additionto the respiratory symptoms of a cold.

Another reason babies get sick so often is that they are frequentlyaround other children, often siblings, and this exposes them to virusesand bacteria in school and daycare. Children in schools and daycare getmore colds, runny noses, and ear infections than children cared for athome. However, their earlier exposure to these diseases also leads themto develop immunity earlier.

Babies are also curious about the wide, wonderful world they areborn into. So they will stick anything and everything into their mouth asa means of exploring that world. You can imagine the enormous amountof germs that ride along.

Furthermore, babies have not developed the immunity to the manydifferent viruses that cause colds, because they haven't had time to acquirethe antibodies to fight off viruses. Babies do have some of theirmothers' antibodies when they are born, which were transmittedthrough the placenta during pregnancy. This kind of immunity isn't permanent,but breastfeeding can extend it, because many of the mother'santibodies are present in her milk. This is why breast-fed...

Details zur Ausgabe

• Verlag: The Experiment
• Erscheinungsdatum: 2013
• Sprache: Englisch
• ISBN 10: 1615190872
• ISBN 13: 9781615190874
• Einband: Taschenbuch
• Anzahl der Seiten: 368
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: preigu; mail@preigu.de; ; Lengericher Landstr. 19; Osnabrück; 49078; Deutschland