Two
“Who wants to break?” Elton Elijah King asked, removing the frame that held the billiard balls in a triangle shape on his parents’ pool table. Dylan Wren leaned on his crutches, staring down at the table.
“How’d you guys get a pool table?”
“A guy who was remodeling his house gave it to my parents, because he couldn’t afford to pay them for singing in his jazz club.” King extended a cue enticingly. “So, you think you can beat me?”
Dyl grimaced. “Actually, I’ve never played pool before.”
JJ shook her head, making her blond ponytail wiggle behind her. “Neither have I, but that doesn’t mean I’m not ready to learn.”
King nodded. “All right, then. Who has played billiards before?” Under his breath, he hummed the tune to “Jeopardy.”
“Believe me, I’ve played before.” Tony Vasquez ran a hand through his curly brown hair. “I just never bothered to get very good at it.”
Song-Ye Park took up a pool cue. “Pfft. There’s nothing to it.” She rubbed chalk on the tip of the cue and moved the cue ball into position, leaning forward. She put one hand on the table to steady the long stick, and with a flowing movement, hit the cue ball. The white sphere shot forward and broke the rack perfectly, sending the balls rolling in all directions across the table. A striped ball clunked into a corner pocket. “And that’s all there is to it,” she said. “Actually it’s mostly math, good eyes and a steady hand.”
The cue ball had ricocheted off the striped ball it had hit into the pocket, then off the felt-covered side of the pool table. Song-Ye knew that one of the most important elements in a successful pool game was the law of reflection. A good pool player was able to calculate the angle from which the cue ball needed to be hit to bounce off the table’s walls and hit the next target ball.
She slid the cue between her fingers. Equally important was knowing and understanding Newton’s Laws.
Her mind rapidly figured that she needed to hit the cue ball at a 40-degree angle to hit the next striped ball. She knew where to point her cue on the cue ball to get it to spin properly. And she figured the amount of force with which she had to strike to get the right amount of speed. It was all science, a good eye, and a steady hand. Just one more example of the everyday value in understanding science.
Another perfect hit! The ball sank into the side pocket.
“Sounds like something JJ would be good at,” Tony said with a smile and a wink.
JJ grinned. “Oh, speaking of math, how did you do on your last test?”
“Got an 89, thanks to your tutoring. But I can do better,” Tony said as he took a pool cue from the rack on the wall.
“We should probably put in some extra hours of studying, just to make sure.”
“Hey, if there’s math in playing pool, maybe you can figure out a way to get extra credit,” Dyl said.
Tony groaned. “I’m taking algebra. Billiards would be geometry.”
“And a bit of physics,” King added.
“Oh,” Dyl said. “This could be a problem.”
King waved his hand in a dismissive gesture. “Huh-uh. This is easy stuff—stuff you know already. But maybe you don’t know that you know, if you know what I mean.” He grinned.
Tony approached the table, and mimicked what he’d seen Song-Ye do with the pool cue. However, he didn’t know how perfectly she’d calculated everything prior to her shot. He struck at the cue ball haphazardly. The ball rotated, spinning like a planet in place on the table.
“Apparently Tony just reminded us there’s a difference between know-know and no-no?” Dyl joked.
“I thought we were here to play billiards,” Song-Ye said, sounding testy.
Dyl shrugged. “Oh, we are. But really, you could think of it as another study session. We’ve got to be ready for our next mission! Never know what that will be. Anything we learn might help us to figure out how to stop the Kylarn invasion!”
“Uh-huh, and I figured my parents’ basement was a pretty private place where we can talk without getting interrupted,” King said. “My parents think it’s kind of cool that we’re bonding because of the Challenger Center.”
Song-Ye rolled her eyes. “My parents are just happy that I’m learning to be social.”
King started humming “You’ve Got a Friend in Me.”
“So what’s the physics in this game, King?” JJ asked.
“It’s about Newton’s Laws of Motion,” King said. “You know who Newton was?”
Song-Ye gave a heavy sigh. “Newton … I miss him. I wish I could see him every day, instead of having to keep him in his cage at the Challenger Center.”
“The little guy is cute,” JJ said, “but he’s from the future, and Mr. Zota wants to be careful that a hamster doesn’t change anything in our time.”
Song-Ye tucked her straight black hair behind her ears. “I’m not sure what a hamster could change, even if he wanted to.”
“Not any old hamster—a hamster from the future,” Dyl pointed out.
“Not helping, Junior,” Song-Ye said.
King gave a sharp whistle. “I’ve got the next best thing to a hamster.” A moment later, a dog with silky red fur bounded down the stairs into the basement and greeted King with frantic enthusiasm. “This is Copernicus.”
Song-Ye gasped with delight and went over to introduce herself to the dog, letting him sniff her hand before petting him. The large Irish Setter sniffed all the young people and seemed to approve, demanding to be petted by each one in turn.
“So, back to Newton—the scientist, not the hamster,” King said. “This month I’ve been learning his Laws of Motion online as part of my Three New Things that Commander Zota assigned us. Newton’s first law goes like this.” He picked up a billiard ball and set it down carefully in front of him. It stayed perfectly still where he put it. “An object at rest wants to stay at rest. It doesn’t want to move unless something comes along and moves it.”
Tony laughed. “Just like me on Saturday mornings.”
Dyl pulled a note card and mechanical pencil out of his pocket, and made a note. “Newton’s Law 1: an object at rest tends to stay at rest.”
“The first law also says that something in motion will just keep on going at the same speed in the same direction, unless something else affects it.”
Dyl wrote, “An object in motion will stay in motion.”
“Are you sure?” Tony asked. “Because if this table was a mile long, and I rolled a ball down it, the ball wouldn’t keep going for the whole mile. Watch.”
Tony grabbed another ball, and gave it a light nudge across the green felt that covered the table. It slowly rolled to a stop.
King nodded. “So some kind of force is affecting it.”
“Like gravity,” JJ pointed out. “It was a lot easier to jump or to throw things a long way when we were on the Moon, because it has so little gravity.”
“And friction,” Tony pointed out. “It’s rolling on something.”
“Okay, I get it. So things want to stay still if they’re still, and they want to keep going if they’re moving, unless something interferes with that,” Dyl scribbled furiously. “And I suppose that Newton’s next law is about whatever makes something stationary move, or something that’s moving stop or change direction.”
“Something like that,” King said. “It’s about how force comes from speed and mass.”
“Hmm, I go to Mass every Sunday,” Tony chuckled. “But believe me, it’s not very fast.”
Song-Ye rolled her eyes. “As in, you really don’t know what mass is?”
“Of course I do,” Tony said. “It’s something about size, isn’t it? Or … density or something?”
JJ said, “I think it’s closer to weight. Or not weight exactly, but how much stuff is in something … density and size?”
King nodded. “Yup. The size and density of an object gives us its mass. Okay, what happens when something big hits something little?” He hummed the theme to The Big Bang Theory.
“Trick question,” JJ said. “It depends on more than size—it’s how much stuff, or mass, the big thing and the little thing have.”
King rummaged around in a box beneath the table and pulled out a hollow plastic ball with air holes in it. “What happens if I roll this at a pool ball that’s standing still?” He rolled it slowly toward the cue ball. The lightweight plastic ball tapped the cue ball, which only jiggled a bit.
“Doesn’t do much,” Tony said. “So a holey plastic ball hardly affects the billiard ball, because the swiss-cheesey ball has a lot less mass?”
“Sort of,” King said. “But what if I change the plastic ball’s speed by throwing it at the cue ball really really fast?”
“It should have a lot more effect on the cue ball, even though the cue ball is heavier than the ball with holes in it,” Dyl said.
King grinned as he demonstrated. He threw the plastic ball hard at the cue ball. The collision was loud and moved the cue ball a few inches on the table. “See? I told you that you knew this stuff already. It’s easy.”
“But what about things that are the same size, shape and weight?” Tony asked. “Like these balls on the pool table? Don’t they have the same effect on each other?”
King gave Tony a high five. “And you’ve just discovered Newton’s third law: For every action, there is an equal and opposite reaction.”
Dyl said, “So, I must be affecting Song-Ye, because she always has the opposite reaction to things that I do.”
Tony ignored him. “I think I get it,” he said. He grabbed the cue ball and rolled it across the table at a striped ball until they clicked together. The cue ball stopped rolling, and the striped ball started moving toward the other side of the table. “They both have an effect on each other: The cue ball was rolling, but when it hit the other ball that was the same size, shape, and weight, it stopped rolling, and the other one started.”
“Right, but it gets a lot more complicated. Like, what if both things are moving and they hit each other, or what if an object just hits the edge of the other object instead of hitting it head-on—”
Dyl shifted his weight on his crutches. “Or what if something big and heavy like a car hits something small and squishy, like a kid on a bike? Now that’s complicated!”
JJ winced, and Tony said, “I don’t think anyone can calculate that.”
Surprisingly, Song-Ye said, “Science can’t measure emotional impact. At least not by Newton’s laws.”
“Let’s keep it simple then,” King said. “What if we roll two billiard balls at each other from opposite sides of the table, and one of them’s rolling faster than the other? What happens when they hit?”
JJ said. “If they have exactly the same mass, the one that’s going faster should have a little more effect on the one that’s going slower.” She slammed a green six ball against a black eight ball. The eight ball was moving a little faster and bounced the six ball away a little farther.
“Okay,” Dyl slid his notecards back into his pocket. “Then I guess I’m done with extra credit for the day. Show us how to play pool.”
Song-Ye picked up her pool cue again. “Watch and learn.”
***