When I was a little boy, I loved to watch and feel the tide come in. On summer days I would stand on the beach in front of our house with my toes barely touching the edge of the water. Ever so slowly the rising sea would creep in around my feet and then crawl steadily up the beach behind me, filling in my footprints one after another. If I was patient and stood still for a long time, little minnows would swim in from the deeper water and gather around my feet. When they bumped against my ankles it tickled.

Minnows are very curious, and always looking for food.

 

Later on, when I was a little older, I learned that on Cape Cod the tide comes in and goes out every twelve hours, or two times in a twenty-four-hour day. It seemed to me that this steady, never-changing rhythm was kind of like the Earth breathing. In … out. In … out. In … out. But each breath the Earth took was very very slow. The water on my beach inched forward little by little, then slipped away again just as slowly. This made sense because I could see that our Earth was huge, especially compared to a little boy like me. Since the world is so big, I thought, each breath must take a really long time to bring in and let out—hours and hours.

By the time I was nine or ten, I was planning my summer days around the tides. At low tide, when the water had retreated, we had much more beach to play on. Low tide was the time to play stickball with my cousins, or build sand castles, or maybe dig some clams for dinner. When the water came in again at high tide, we ran around in the shallows, chasing and splashing each other with lots of shrieking and laughter.

I loved to watch the little fish and crabs that followed the water on the incoming tide. The minnows traveled in schools, darting here and there trying to catch tiny creatures I couldn’t see. Every once in a while a bigger fish would come flashing in from deeper water and grab some of the little ones. When the tide was high, the crabs liked to crawl into the seagrass that grew in clumps along the beach. They’d often dig themselves into the sand to hide when I came near.

I also noticed that some of the grass would be completely covered by the water at high tide, but that only seemed to make it grow better. I could see that the movement of the tides was very important to all these animals and plants living along the shore.

When I first told my dad about how the tides were like the Earth breathing, he just smiled. When I was a little older, he told me that the real reason the water comes in and goes out every day is mostly because the moon and the sun are pulling it back and forth. “When you throw a ball up in the air, it falls back to the ground, right?” he said. “That’s because the Earth is pulling it,” he explained. “We call the pull of the Earth gravity.

“The moon has gravity too,” he added. “The moon pulls our oceans toward itself and away from the Earth. And that makes the tide go out.”

I listened and tried to understand. “Okay,” I thought, “so maybe the moon does help the tides come in and go out.” But secretly I liked my breathing idea better. It was exciting to think of our Earth as a great big round living thing, breathing in and out like we do, only much more slowly.

NOW I’M AN OLD MAN. For seventy years I’ve lived near the ocean, watching the tides come in and go out, and learning about all the fish and other animals and plants that live in the water.

During my lifetime scientists have been studying the Earth and how it works. And guess what? The Earth is alive. It does breathe. Even more amazing, when it breathes, it helps all of us living things breathe too!

This summer my grandchildren are coming to visit me on Cape Cod, and they love to play by the ocean just like I did at their age. (I still do!) I’m hoping that they will help me learn more about how the Earth lives and breathes, and how the living Earth keeps us alive.

My grandson Tom is thirteen. He lives with his sister, Julie, and their parents outside Boston. (You can tap the map on the next page to see where they live.) Tom is in middle school—he’s especially good at math, and loves to play soccer and tennis. He is also fascinated by flying and space travel.

Map of the United States
Boston is a city on the East Coast, close to Cape Cod.

Julie is ten, just finishing fifth grade, so she’ll move on to the middle school next year. In school, her favorite subjects are English and science. Spending time with friends is important to her. Julie has always loved the ocean and seems really at home here on the Cape.

A few weeks ago I stayed with them at their house in Boston, and we had a chance to talk about fun things we could do while they’re on the Cape.

“I want to go boogie boarding on Nauset Beach,” Tom said, “and go out fishing for striped bass and bluefish.” Tom and his dad have done a lot of fishing together, and sometimes I go with them.

“Me too on the boogie boarding!” Julie exclaimed, sweeping the hair out of her eyes, “and I want to visit the seals in the bay. And, Gramps, could we go sailing in your sailboat?”

“Of course you can!” I caught her as she danced by and gave her a hug. “You know I love to sail, and those other ideas are great too. Now let me tell you what else I’d like for us to do.” Both children looked at me expectantly.

“I want you to help me look for Goldilocks,” I announced.

Their faces changed to surprised and confused. “Goldilocks?” said Julie. “We know where to find Goldilocks. She’s in the fairy tale about the three bears.”

I smiled, because of course she was right. “Do you remember the story?”

“Sure. Goldilocks went for a walk in the woods and came to a little house. She knocked on the door but nobody answered. The door was unlocked, so she just went in.”

Julie paused to remember what happens next, and Tom picked up the story. “She found three bowls of porridge in the kitchen. Porridge is like oatmeal. She was hungry, so she decided to eat some.”

“Right!” Julie agreed. “And the cereal in one bowl was too hot, and in the next bowl it was too cold. I can’t remember which was the Papa or the Mama bear’s bowl. But I know when she tried the baby bear’s porridge, it was juuust right, and she ate it all up!”

Tom wanted to add something. “Goldilocks also went upstairs because she was tired and tried out the beds up there. It was kind of like the porridge. One bed was too hard, one was too soft, and the third one was just right. So she lay down and fell asleep. When the bears came home, they found her there.”

“Perfect. You remember the whole story. So, Tom, what’s the Goldilocks story telling us, do you think?”

Tom looked away and thought for a minute. “I think it’s saying that things can be too much one way or too much the other way, but somewhere in the middle they are just right.”

Julie was impressed by Tom’s explanation. “Like the baby bear’s porridge wasn’t too hot or too cold,” she said tentatively. “It was just right!”

“That’s exactly what I mean by looking for Goldilocks,” I explained. “I want you to help me understand more about this planet we live on, and what makes it just right as a place to live. So looking for Goldilocks is looking for just right.”

“I see,” said Julie. “So Goldilocks is sort of code for ‘just right.’”

“Exactly,” I responded.

Just then the kids’ mom called us all into the kitchen for dinner. Afterwards I sat around with them while they did homework, and we talked some more. “I know you two have been studying Earth science in school,” I began. “And I’ve been reading about some of the cool new things scientists have been learning about the Earth. Have your teachers ever talked about Gaia?”

Both children looked at me blankly and then at each other. “Never heard of it,” Tom said. “What’s Gaia?”

“In ancient Greece, Gaia was a goddess who was the mother of everything there is, and she represented the Earth. Now some scientists are using her name to talk about how the whole Earth is a living thing, where everything works together.”

“When I found out about that idea, I really liked it,” I went on. Since they still looked confused, I tried a different explanation. “When I was a kid, I loved to stand on our beach and watch the tide come in. It felt to me like the whole world was slowly taking in a big breath. Then when the tide went out I imagined the Earth was breathing out again. It made me feel like the world was a living, breathing thing.”

“That’s a cool idea, Gramps,” Julie murmured, her eyes bright. “I like to think about the whole Earth breathing.”

Tom was more doubtful. “At school we learned that tides are caused by the gravitational pull of the moon and the sun,” he explained seriously.

“That’s true,” I agreed. “When I was older, my dad told me how the moon affects the tides, and I noticed that we got higher tides when the moon was full. But the idea of Earth breathing is more than just the tides.

Scientists use the Gaia theory to show us that the Earth is one great big organism, like an animal.”

“Really?” Julie got so excited that she popped out of her chair. “You mean it’s alive like a person, only humongously big?”

“Not exactly,” I responded. “But the idea is that the Earth has working organs, like our heart and our lungs.”

This mention of organs caught Tom’s attention. “What do you mean, the Earth has organs?”

“Well, you know that an organ is a part of your body that helps keep you alive, right?” I replied. “For example, our lungs are the organ we breathe with. If you put your hand on your chest and breathe in and out, you can feel your lungs working.”

Both children put their hands on their chests and breathed deeply. “Okay,” said Tom, “so what are Gaia’s lungs?”

“Most of the plants on land breathe too,” I replied. They take in carbon dioxide gas from the air, and they breathe out the oxygen that we humans and other animals need to breathe. So the land and the plants that live on it make up one of the Earth’s organs— kind of like our lungs.”

Tom went silent with his mouth a little open, thinking about the Earth breathing. After a minute he suggested, “I would think of the land as being more like our skeleton, holding up everything that lives on it.”

“That’s true too,” I agreed. “Scientists talk about the Earth’s crust, and how it has moved and changed over millions of years.”

Julie had a question. “What about the oceans?” she wanted to know. “Are they an organ like the land?”

“Good question!” I said. “Scientists think that the oceans are kind of like our heart and blood vessels. You know how the heart moves the blood around in our body through our arteries and veins? The arteries and veins are like the currents in the ocean that move warm water into cold parts of the world and cold water into warm parts of the world.”

Because he’s a fisherman, Tom knew about ocean currents like the Gulf Stream, which brings warm water up the east coast from Florida. He wanted to know more. “Are the land and the oceans the Earth’s only organs, or are there more?”

“There’s one more really important organ,” I replied, “and that is the atmosphere.”

“Which of our organs is the atmosphere like?” Tom wondered.

I was glad I had read up on the Gaia theory because these two were really testing me. “The atmosphere is like your skin. Did you know that your skin is the largest organ in your body? The atmosphere around us protects the whole Earth from the incredibly hot rays of the sun, just like our skin protects everything inside our bodies. But the atmosphere also holds onto some of the sun’s heat, like a blanket—kind of like how our skin holds in the heat our bodies make when we walk or run.”

Like most kids in middle school, Tom had been learning about the human body. “I know that the organs in our bodies work together to keep us alive. Our skeleton holds everything up. Our heart and lungs team up to get oxygen from the air we breathe and carry it in our blood to other parts of our body. Our skin holds heat inside our body to keep us warm, and lets out sweat if we get too hot. So what about the Earth—do its organs work together like ours do?”

“That’s exactly what the scientists have figured out,” I said. “They’ve learned how the land, the oceans, and the atmosphere work together to make the food we eat and the water we drink. Also, these organs join forces to keep the air around us the right temperature—warm enough so we don’t freeze and cool enough so we don’t burn up.”

Julie’s eyes went bright again. “You mean like Goldilocks … not too hot and not too cold?”

“Just like Goldilocks!” I answered with a laugh.

Tom high-fived his sister, a rare compliment. “Okay, Gramps,” he reminded us. “You said you want us to look for Goldilocks this summer when we’re on the Cape. So how do we do that?”

“Actually I think we need to start by looking at the whole Earth,” I suggested, “and then see what we can learn from the land and the water and the atmosphere right around the Cape. Once you get there we’re going to be spending a lot of time outside,” I reminded them.

“The whole Earth?” Julie scrunched up her eyebrows like question marks. “You mean like with a globe or something?”

“We could do some exploring with Google Earth…” Tom offered.

I’d been saving a surprise. “Sure, but I have a more exciting idea,” I said. “You know that friend of mine I’ve talked about—the ex-Marine pilot at Hansom Air Base?”

Tom had been sitting on the couch idly tossing a tennis ball up and down. At my mention of the pilot he suddenly sat up straight. “You mean the guy who flies a little spacecraft and takes people for rides up into space?” he asked, his voice going high with excitement.

“That’s the guy. He’s offered to take me up sometime, and I’m going to ask if we can all go together in the next few weeks. I already spoke to your mom and dad, and they’d be okay with it. What do you say?”

“Oh … wow!” Tom whispered, looking over at Julie. “A ride in a rocket ship!” Tom loves to fly, but he knows that flying in space is different from flying in a regular airplane. “Will we be wearing space suits and helmets with oxygen piped into them?” he asked, both eager and a little nervous.

“We will,” I affirmed. “Bing has a regular business flying people up into the atmosphere to look around and take pictures. So we’ll be perfectly safe with him.”

Julie finally found her voice. “For real?” she asked me. “For real.” I said.