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THE WHYS OF THE WORLD
Know the answers: about quicksand and chameleons, butterfly wings and the bounce inside a rubber ball. A direct follow-up to the bestselling How Come?, HOW COME? PLANET EARTH explains 125 mysteries about the world we think we know best. Here are questions about Earth—how volcanoes erupt and why oceans don't overflow. Questions about animals, from camels' humps to a cat's purr. Questions about people—sleepwalking, warts, and why bruises are black and ...
THE WHYS OF THE WORLD
Know the answers: about quicksand and chameleons, butterfly wings and the bounce inside a rubber ball. A direct follow-up to the bestselling How Come?, HOW COME? PLANET EARTH explains 125 mysteries about the world we think we know best. Here are questions about Earth—how volcanoes erupt and why oceans don't overflow. Questions about animals, from camels' humps to a cat's purr. Questions about people—sleepwalking, warts, and why bruises are black and blue—and a section called "Factory Field Trip," on how we make things from mummies to chewing gum to microwave ovens.
A NOTE TO PARENTS: No one remembers all those science facts, but HOW COME? PLANET EARTH and the original How Come? help with even the trickiest science questions. So the next time your child asks why stomachs growl or how a jet airplane works, here are the answers.
What causes quicksand?
Fans of the old Lassie TV show from the 1950s and '60s—or just about any kids' adventure show from that period—have fond, scary memories of quicksand. A character is strolling along, minding their own business—little Timmy or Flicka the horse, or Rin Tin Tin the dog—and suddenly they feel the solid ground give out from under them. Whichever character hasn't fallen in goes for help. And using tree branches or brute force, Gramps or Lassie or a horse named Fury slowly pulls the sinking someone out of the quicksand and safely onto hard ground. What is quicksand? Quicksand is ordinary sand that has become what scientists call "quick." Clay can also become quick, and there are quick bogs and swamps too. "Quickness" is the way water flowing through sand, clay, or other material can lift and separate its small grains.
In ordinary sand, whether wet or dry, sand particles are pushed up against each other. But when sand becomes quick, an invisible cushion of water holds sand grains a bit apart. So what looks like a solid surface is really—oops!—liquid, a thick soup of water and sand.
In quicksand patches, ordinary sand is sitting on top of a body of water, such as a bubbling spring. The water is trying to push upward; the sand is weighing the water down. The sand becomes "quick" when the water pressure underneath balances out or exceeds the weight of the sand above. As each grain is surrounded by a thin film of water, the sand particles lose contact and friction. Toss a rock onto what looks like solid sand, and you'll see it disappear below the surface, just as if you'd thrown it into a lake.
Any kind of sand—rough or smooth, mixed with pebbles or not—can become quick. But heavier grains need a more powerfully surging spring to lift them, while the finest-grain, roundest sand can become quick even from weakly flowing water.
Quicksand is found everywhere water and sand live side by side—creek beds and ocean coasts, prairies and mountains. One good place to find it is in hilly country, with lots of limestone caves dotted with underground springs; such springs breed quicksand above. When you're hiking, watch out—quicksand may be hidden under leaves, or by a dried-out crust of mud.
Even if you stumble into a quicksand patch, you'll probably live to tell the tale. No matter what you see in movies or old TV shows, quicksand doesn't suck you in, any more than a lake does. In fact, quicksand is actually more buoyant than water. So unless you're wearing a ton of camping equipment, you'll float quite nicely. To extricate yourself from quicksand, squirm out of anything heavy, such as a backpack, and calmly swim or dog-paddle to solid ground.
Big, heavy objects sometimes fall into quicksand, with disastrous results. In the 1800s, a freight train derailed off a Colorado bridge and plunged into a "dry" creek bed, made quick by a recent flood. Railroad workers found most of the cars, but the 400,000-pound engine had
What Are You Wondering About?
How does Earth maintain its speed of rotation? Why doesn't it slow down?
How was Earth formed, and what was it like in the beginning?
Does air weigh anything?
Why do trees and other plants take in carbon dioxide, while we take in oxygen?
What makes a volcano erupt?
Why don't we have ice ages anymore?
If you dug all the way through Earth, would you end up in space?
What causes quicksand?
Why do some mountain ranges look blue if they are covered with green forests?
How come there are deserts?
How do lakes form?
If the rivers drain into the oceans, why don't the oceans fill up and overflow?
How do islands form?
How do icebergs form?
What are the jet streams, and what causes them?
What causes the different shapes of clouds?
Why are rain clouds black in color? What happens to clouds after they form?
What causes the sound of thunder?
Why does a rainbow always form an arch?
What makes dew appear on grass?
What is the cause of fog?
Why do jet airplanes leave trails in the sky that look like clouds?
Why does the sky turn colors at sunset?
How is Earth like a magnet?
Is it true draining water swirls in opposite directions north and south of the equator?
Why do ships and planes disappear in the Bermuda Triangle?
Why do we seem to see a face in the Moon?
Why does Earth have only one moon?
How come Earth doesn't have any rings?
Where does dust come from?
How do fish breathe underwater?
How come fish and dolphins don't sleep?
Why do some sharks die if they stop swimming?
If whales can't walk, why do they have hips?
Do whales really sing?
Why are electric eels electrical?
How does a chameleon change its color?
How can a hummingbird fly both forward and backward?
How do birds know where south is?
Why are butterfly wings so colorful?
How come moths eat wool?
Where do bugs go in cold weather, reappearing like magic when it warms up?
How many eyes does a fly have?
How do you get lice, and how do you get rid of them?
Why do elephants have such big ears?
How can camels survive with little or no water?
Why does a porcupine have quills? How do they work?
Why do raccoons have black masks?
Do flying squirrels really exist?
How do cows digest their food?
Why do dogs bark?
How do cats purr?
Why do cats' eyes shine in the dark?
How do animals communicate without language?
How come so many animals have tails (and we don't)?
How did dinosaurs get their long and difficult names?
Why do animals become extinct?
Why do fingers get wrinkled after soaking in water for a long time?
Why do people get goose bumps?
Why do we get bruises? And why are they black and blue?
How does blood stop flowing out of a cut?
What makes your nose bleed?
How does hair grow?
Why does hair mostly grow on our heads?
Why do men seem to lose their hair more often than women do?
Why do we get pimples?
What causes warts?
What causes freckles?
Why does the sun make our skin darker, but our hair lighter?
Why and how do we get fevers?
Why do our ears pop when we fly on a plane or drive in the mountains?
Why do people sneeze?
What makes us allergic to things?
What causes an itch, and how come it feels better when you scratch it?
How does the nose smell things?
How come chopping onions makes you cry?
What gives foods their different tastes?
Why do our faces flush, eyes water, and noses fun when we eat hot, spicy food?
What is cholesterol?
Why is cigarette smoking bad for the lungs?
How does alcohol affect the body?
Why does our breath smell bad, especially in the morning?
Why do people burp?
What makes your stomach growl?
How come acids in the stomach don't destroy it?
Do we really need an appendix?
Where do our voices come from?
Why do people snore?
Why do we need sleep?
Why do people sleepwalk?
What causes headaches?
How do muscles work, and how do you build muscles?
How does the heart work?
What is high blood pressure?
Why do we run out of breath when we run?
How does sweating work?
Where does the fat go when you lose weight?
What is the difference between identical and fraternal twins?
What makes our eyes the color they are?
Why do we giggle when we hear jokes?
Why do we sometimes feel that what we're experiencing has happened before?
Factory Field Trip
How is chewing gum made?
How is chocolate made?
How is decaffeinated coffee made?
Why does rubber bounce?
How is glass made? How is it shaped into drinking glasses and pop bottles?
What is perfume made of? And where do they come up with the fragrance names?
How are diamonds formed?
How do gems form and how do they get their color?
How is silk made?
How does detergent get clothes clean?
How does a refrigerator work?
How does a microwave oven cook food?
How does a radio work?
How does a compact disc play music?
How does a mercury thermometer work?
How does hot air lift a balloon?
How do jet airplanes fly?
How is paper made?
How does glue work?
How does a magnifying glass work?
How does camera film record pictures?
How do electric lightbulbs emit light?
How does a telephone work?
How were mummies made?
Posted October 7, 2008
I purchased this book for my grandson who was seven at the time. He keeps it in the car and reads it whenever he is in transit. If I am there he reads it to me. Both of us have learned many interesting facts. I am now going to purchase How Come Planet Earth for my 5 year old grandson, who, although he will not be able to read it for himself will thoroughly enjoy the book. I highly recommend this book for any youngster who has expressed curiosity about the world around him/her.Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.
Posted August 28, 2006
This book has been amazing! We have turned our little Chatty Patty into an information guide. If you have to hear it, might as well focus the talker in the family! We are all learning quite a bit and our son LOVES teaching us about sneezes, quicksand, and all the how to's in life! EXCELLENT BOOK!Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.
Posted December 28, 2003
Posted March 31, 2000
The first 'How Come' book (just called 'How Come?') has been one of my favorites ever since it was published a few years ago, so I was overjoyed when I heard that there was a new How Come? book out. How Come? Planet Earth is just as good as the first -- full of all the answers to all those science questions you've always wondered about. This is a great book to keep on your coffee table or bedside table, and just read a few items every day. And, just as in the first How Come? book, the drawings are hilarious and make this book the perfect gift for anyone who's ever wondered 'How Come'?Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.
Posted May 9, 2009
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