by Nate Ball
Then I saw Amp running at me from the opposite direction, across the dimly lit grass, his arms held up like he wanted a hug.
That’s when I knew he was going to miss me as much as I was going to miss him.
In one smooth, quick motion, I scooped him up, gave him a trembling smile, and dropped him through the open hatch on Ohm’s steaming and clicking spaceship.
This was not how I imagined our good-bye moment.
“ZACK, WAIT!” Olivia seemed to shout from a million miles away.
“NO TIME!” I croaked.
I adjusted my grip just as Amp’s little head came poking up out of the still-open hatch. I gently pushed him back down with my index finger and closed the hatch with my palm. It clicked tightly into place.
The watch’s alarm would surely stop at any moment.
“NO! WAIT!” Amp’s voice shouted inside my head.
“Sorry, pal,” I said. “We’re out of time. I’ll never forget you!”
The spaceship began to vibrate and hum.
Like a great hunter from mankind’s distant past, I took three giant leaps forward across our dark backyard lawn, and executed the best throw of my life.
The dimly glowing spaceship shot high in the night sky and kept rising over the roof of our garage.
The beeping on my wrist stopped suddenly.
“We made it,” I gurgled.
The flung spaceship seemed to rise impossibly high and fast. Just as I thought it might hit the top of its flight path, it expelled a huge blast of yellow fire—the secondary launch boosters!—which knocked me back a few steps like a punch to the chest.
The loud boom seemed to echo through the entire town. Every car alarm for three miles seemed to jump to life. Every dog in our neighborhood began barking and howling.
I felt Olivia step next to me. She put a hand on my shoulder. I didn’t look over, as the hot tears that had been building up in my eyes now ran freely down my face.
We stood in silence and watched the spaceship rocket through the night sky, like a falling star that seemed to be falling up. The moon, which looked like a giant bowl of milk, seemed to be waiting for it.
I couldn’t help it. The tears continued. I couldn’t stop the sobbing. I didn’t care if Olivia saw me. I felt like I had just lost a family member.
Olivia, obviously feeling bad for me, wrapped an arm around my bouncing shoulders.
“Don’t take it so hard, Zack. You had to do it. Besides, it wasn’t your fault.”
I sniffed. “My fault? What do you mean?”
“We still have time.”
I blinked through tears. “Huh? Time for what?”
“To launch Amp, of course,” she said, looking back.
And there sitting on the fence behind me was a bug-eyed Amp, peering up into the night sky with his mouth hanging open in shock.
And that’s when, for the first time in my life, I fainted.
Grounded for Good?
I woke up on the dusty couch in Olivia’s garage.
“Good. You’re not dead,” Olivia said softly.
I groaned. “What—?”
“You weigh more than two beached whales,” Olivia said, sitting on a tall stool directly across from me. “I almost broke my back dragging you in here.”
I sat upright, the crazy series of events coming back to me in an instant.
“Amp?!” I shouted, now seeing Amp sitting just like Olivia on a stool of his own.
“Honestly, I can’t believe your ball thrower idea worked,” Amp said, smiling.
“But I thought that was you I put in the spaceship!” I said, still trying to make sense of what had just happened in my backyard. “I thought you were trying to hug me.”
Amp laughed. “Ohm is not a hugger.”
“That was Ohm? I could have sworn that was you,” I said.
Amp shook his head. “He was trying to stop you. After Olivia’s mechanism failed, we were going to wait for the next launch opportunity twenty-eight days from now.”
Olivia shook her head. “Then, like a crazy zombie, you have to show up and take things into your own hands. That was amazing, Zack.”
“You may have saved your fellow earthlings a lot of problems,” Amp agreed.
I fell back into the couch cushion behind me. I winced at the pain in my back, probably from my fall from the ladder. “I did it,” I said, staring blankly into the garage rafters above us. “And Ohm should be able to call off the invasion, too. I sort of just saved the world.”
“Hopefully,” Amp said. He sighed to explain. “Space travel is an inexact science. He might make it home in time—or he might not. I’d put the odds at about a million to one.”
“Seriously?” I said, throwing up my arms. “How you guys have ever successfully invaded a planet is beyond me.”
“Who says we have?” Amp said, confused.
“Well, look on the bright side, Zacky. At least you get to see Amp again,” Olivia said with a shrug. “It was really sad when you didn’t show up to say good-bye.”
“Ohm tied me to my mattress with kite string and bungee cords. I had to escape like Houdini!”
“You did?” they both said at the same time.
Olivia shook her head in disbelief. “Wait, Ohm did say that you were tied up at the moment, but I didn’t think he meant literally. I assumed you were in trouble again.”
“He didn’t want me getting in the way,” I said. “He said Amp liked me too much.”
“Really? I can’t believe he said that,” Amp said with a sly smile.
“Why weren’t you on that ship?” I asked, still confused. “What if we can’t fix your spaceship? You’ll be stuck here.”
“Neither of us were on that ship,” Amp said. “Like I said, once Olivia’s launcher failed, we called the launch off. We tried to tell you, but—”
“We’ll fix your ship, Ampy,” Olivia said firmly. “Especially now that we have an initial launch system that we know works. It’s been field tested.”
“What happened to your launcher?” I asked.
Olivia blew out a big breath. “It sort of fell apart. I ran out of time. My glue gun got clogged. I broke three springs. It actually fired off before I was ready.”
“Fired off?” Amp complained. “It basically just snapped. I bit my tongue when Ohm’s ship hit that tree.” This made us all laugh, as Amp pulled on his tongue to show us the damage.
“Well, guys, that’s enough fun for me for one night,” Olivia said, standing up and yawning. “I don’t want Grandpa to find my bed empty at this hour of the night. Plus, we’re both going fishing in a couple of hours.” She groaned and stretched.
“There is one great thing about all this,” Amp said. “Zack and I can finish watching The Mummy. C’mon, let’s go!”
I smiled, reached out, and held up my hand up for a high five. He gave me a high three, which was the best he could manage.
“You love that movie,” I said.
“We can worry about getting me home tomorrow.”
And with that, we headed back to my house.
His broken spaceship and everything else would have to wait till the morning.
We had a movie to finish.
Try It Yourself: Atlatl
Have you ever heard of the term leverage? As in, “We need to get a bit more leverage”? Zack cleverly uses a ball-throwing toy, usually used for chucking tennis balls for his dog, to get himself more leverage for throwing Ohm’s ship into the air. You’re probably already much more familiar with the concept of leverage than you think.
Levers are all around you. As Ohm points out in his note to the Erdian Council, a lever is basically a stick that pivots, or rotates, around a certain point. When we’re thinking about the stick as a lever, rather than just a stick, we call that pivot point the fulcrum.
The door to your bedroom is a lever. The fulcrum, or the point that the lever pivots around, is the pin going through the hinges of the door. A teeter-totter on a playground is als
o a lever. Have you ever wondered what would happen if a really big person jumped onto the seat across from you? If the person were big enough, the teeter-totter might lever you right up into the air!
The Levers in Your Body
There are a few levers you use every day, even if you don’t open a door or stop by the playground. Those levers are your arms and legs! Each joint—like your wrist joint or your shoulder joint—act as a fulcrum for those levers. Your hand and lower arm pivot around those joints, acting as levers.
The way the human body’s levers are arranged make them very good for speedy movements because they’re very long. Can you imagine if your end of the teeter-totter grew to double the length it started from? If a big kid jumped on the other end, you’d really go flying!
That’s the same concept Zack takes advantage of when he uses his ball thrower to chuck Ohm’s spaceship into the air. The ball thrower makes his arm—the lever that’s throwing the ship—even longer than it was to begin with, giving the spaceship an extra boost.
Ancient Leverage—the Atlatl
Humans have been using leverage to throw things extra far for a lot longer than tennis ball chuckers have been around. In fact, the first examples of intentionally using leverage for this purpose can be traced back to nearly 30,000 years ago! The most famous example, however, was used by the Aztecs in the sixteenth century, and is called an atlatl. It’s a fantastic example of how a simple tool can augment human capability in a really powerful way.
You can build your own atlatl using a few simple materials.
YOU WILL NEED: Some pieces of cardboard a few feet long (ideally with the corrugations running lengthwise), a roll of tape (like duct tape), scissors, a stick about as long as your forearm, a pen to decorate the cardboard ship, a piece of dish sponge to serve as a soft tip, and an adult to help you cut the materials.
Making the Ship
1. Lay the cardboard lengthwise along a countertop or other flat surface with a corner edge. Use the edge to fold the cardboard along its length, with about a 1-inch width.
2. Fold the cardboard a few times until you can wrap the cardboard around on itself, making a long skinny tube. It can be a triangle, a square, or even rolled into a circle. It doesn’t have to be a perfect shape, but it should be long, skinny, and pretty straight. Once you have wrapped the cardboard into a tube, have a grown-up help you cut off any extra cardboard. Use the tape to hold it in the shape of a tube.
3. Make fins to help the ship fly straight. In ancient times, creating fins with feathers, like on an arrow, was called fletching. We’ll use more cardboard to make ours. You can choose how you shape your fins. Ask an adult to help you cut them. Definitely decorate them—maybe by drawing Ohm’s face on one!
4. Then tape two fins to the bottom of the ship so they stick out evenly on both sides like wings of a plane. Tape another fin to the top of the ship so it appears to have three equally sized fins.
5. Cushion the front tip of the ship with something in case it hits anything delicate. You can use anything that’s small and soft, but a piece of a dry, squishy kitchen sponge can work really well. With help from an adult, cut a little square out and tape it on the tip of the ship.
Building the Atlatl
1. Cut a small piece of cardboard in the shape that’s shown in the picture. Cut it so that the cardboard can fold easily in half along one of the corrugation pieces. Fold the shape in half, and then tape it to the end of the stick.
2. If you can’t find a stick the right size, you can make your own using the same technique you used to make the dart.
3. Tape the folded cardboard shape, or hook, onto the atlatl with one half of the hook on each side. Be sure to tape it tightly, and consider reinforcing it further with some tape. During a good throw, it’s likely to undergo some high forces!
4. You might want to add a little grip on the bottom of your atlatl so it’s easier to hold on to during a throw. You can tape a piece of cardboard onto the bottom of the atlatl, or make up your own grip enhancement.
Launching Ohm Back Home: Throwing with the Atlatl
1. Put the back end of the spaceship, where the fins are, into the atlatl’s hook. Hang on to the atlatl’s grip, and reach around the shaft with your thumb and fingers, using them to pinch the ship’s long body and hold it in place parallel to the atlatl. You’re ready to throw!
2. Throwing with the atlatl uses the same motion as throwing a baseball, so use exactly the same technique. The atlatl will naturally let go of the ship at the right time.
Experiment Time
You’ll probably have some success to start off with, but here are some ways you can work on the design and your own throwing motion to get the most out of your atlatl project.
1. Aim at different angles. Try throwing in a more upward direction. Does the ship fly in the path you expected? How might you adjust the angle you’re throwing at so that it flies along the trajectory you want?
2. Try a different length of ship. It helps to have a longer ship, because it’s harder for a long spaceship to tilt itself in a different course from the one you started throwing it in.
3. Test a different length of atlatl. If a long lever is good, is a longer lever better? Try a few different lengths of atlatl to see which gives you the most leverage. Do different atlatls require different techniques to throw effectively?
4. Try throwing at different speeds. An effective throw will combine raw power with good technique. You may want to experiment with a lower power throw that you can control better before adding additional throwing effort.
Safety Notes
• Do this experiment with an adult! The adult isn’t there to do the experiment for you, and in fact he or she should let you do as much of it as you can. But make sure someone is available to help with the hard parts, like cutting the cardboard and choosing a safe place to throw.
• Choose a safe place to throw! It should be a wide-open area where there are no people, animals, or things that wouldn’t like to get hit with a cardboard spaceship.
• Start small! As with any experiment, don’t ramp up to full power right away. Start with light, easy throws that let you get the hang of it and develop control first. Then ramp up the power after you’ve developed some technique.
• Make sure there is nothing in front of you that can get hit! If you read the prior instructions, you might notice this is mentioned twice. That’s because this is really important! Even though your cardboard spaceship doesn’t weigh very much and has a soft tip from the sponge you taped on, you should never throw it toward anybody.
Digging Deeper
To learn more about the science behind the atlatl you’ve built, look into the physics of projectile motion. The most important thing about the atlatl is that it’s a clever method of getting even more benefit out of the thing our appendages have evolved to be good at: speed.
Your arm is really strong, and also really fast. The cardboard spaceship you’re throwing doesn’t weigh very much—so you can throw it very easily. But because it weighs so little, your body is actually not able to maximize the amount of energy it can put into the projectile when throwing with just your normal arm. The atlatl enables your body to put more energy into the projectile by allowing you to bring it to an even higher release velocity (that means speed) than your hand can during a normal throw.
This can be illustrated by doing another experiment.
1. Hold the cardboard ship and prepare to throw it with just your hand. Have an adult hold your forearm steady and still, so you can only use your wrist to throw the ship. Your hand is functioning as the lever arm. Because the lever arm is so short, you won’t be able to get the ship to a very high speed before you have to let go to throw it. The ship probably won’t go very far.
2. Have the adult hold your upper arm steady while you throw. This way you’re using your hand and forearm as the lever arm. Your lever arm is longer than last time. You’ll be able to achieve a much higher speed than when you were
throwing it with just your hand and wrist alone.
3. Throw it as you normally would, using the length of your hand, forearm, and upper arm. They become your lever arm and your shoulder joint becomes the fulcrum of this throwing lever. The ship should go pretty far!
4. Use your atlatl. The speed at the tip of the atlatl should be even higher than the speed you can make your hand go during a normal throw—meaning it’ll go extra high in the air. It’s that release velocity that matters, and you want it to be as high as possible. Maybe high enough to launch Ohm back into orbit. Be safe, and have fun!
Excerpt from Alien in My Pocket #6: Forces of Nature
Read a sneak peek of book six of the Alien in My Pocket series:
Forces of Nature
What a Trip
“The answer is still no,” Zack said, stuffing a pair of jeans into the canvas bag that usually held his baseball gear.
“Just think about it,” Amp said from atop a pair of rolled-up wool socks that sat on Zack’s desk.
“What part of ‘no’ are you not getting?” Zack asked. “The n or the o part? It’s really a pretty simple word.”
Amp stared off into space dreamily. “I’ve always wanted to go camping.” He sighed.
“What?” Zack said, fixing his eyes on his tiny alien roommate. “Yesterday you had never even heard of camping! Now, suddenly, it’s your lifelong goal? Give me a break, Short Pants.”
“We Erdians are fast learners,” Amp said with a proud shrug of his little blue shoulders. He folded his arms behind his head and nestled deeper into the sock. “Besides, what an adventure! The chance to battle the elements, the opportunity to encounter wild animals, the daily struggle to find food? Who would pass that up?”
“I already told you, we don’t struggle to find food.” Zack groaned, pulling a fistful of underwear from an open drawer and tossing it into his bag. “We bring about five hundred pounds of food with us. We’re not exactly hunting down beavers with bows and arrows.”
