“Newton’s laws of motion!” I said.

“Why are you saying that like I’m supposed to know what it means,” said Kelser.

“No, I don’t expect you to know what that means. I’m saying it out loud because it’s a momentous occasion. You see, Newton was this guy from my previous world,” I said.

“He has a funny name,” he said.

“I know right? All of them have funny names. It’s like that was part of the package. Wanna be a history making genius? Better have a weird name!” I said. “Anyway, there was a fruit on my Earth, called an apple, and it grew on trees. The story goes, this guy named Newton was sitting under an apple tree when one of the apples fell and hit him on his head. Inspired by the way the apple had fallen, Newton went and wrote about stuff like motion!”

“Being inspired by a falling fruit is a little suspicious. Are you sure there wasn’t some sort of magic involved?” asked Kelser.

“The story’s probably an exaggeration. I doubt the guy was hit by an apple and started spouting out statements about velocity and gravity,” I said.

“Right…” said Kelser.

“What really sucked was that I wasn’t able to turn his laws of motion into spells before. I tried, back when I first started making motion magic spells, but they just wouldn’t work. I hadn’t built up enough knowledge or wisdom, but now, after using motion magic for a few months, I think I’m ready to take the next step,” I said.

It was an afternoon on a wonderfully breezy day. The sun had just dipped behind the clouds, rendering the landscape a subtle pale hue. I was sitting near a bend in the river with Kelser. In the distance, I could hear the yells and grunts of a few dozen humans practicing their magic. They were the advanced magic users, many of whom had already started working on light magic spells. Most of them were from the Roja tribe, although as time had worn on, a handful of talented people from the other tribes had joined their ranks. The class was being led by the best magic users in all of the tribes, all of whom were from the Roja tribe and were being supervised by elder Kezler.

By this point in the fall, we’d figured out a nice schedule that let everyone have separate classes with the people right above their skill level. The people who were still stuck at the basics of magic, many of whom were children, were being taught by the people who had just started learning more than one elemental magic spell. Those people were taught by people who had learned all of the elemental spells, who were taught by people who had learned motion magic, and so on until the advanced class that I had just mentioned, who were taught by people like elder Kezler. This way, some people would be free to forage and hunt and do other chores, while everyone could get the magic practice they needed.

The toughest part had been finding the time to teach Kelser while also teaching myself. Unlike Noel, who was good enough to be a partner of sorts, Kelser was younger and less quick witted. He made up for it by being resourceful and naturally talented, but he wasn’t as good at the sort of logical connections and fast thinking that had made me think Noel could come up with her own spells in a few weeks. In fact, now that she was on her own out there, I was sure she’d made a bunch of spells to help her survive.

“The laws of motion aren’t that complicated,” I said. “In fact, after I explain them to you, you might even say they were so obvious I didn’t need to explain them at all. The thing is, articulating stuff like this is difficult. If I told you to define motion for me right now, and to tell me the limits and rules of that definition, I don’t think you’d be able to do it. Heck, I don’t think I’d be able to do it if I didn’t already know about them.”

Kelser thought about it for a second. He had his hand on his chin, his eyebrows furrowed, which made him look really funny. “The stuff I learned about motion for the magic hands spell doesn’t feel like a definition. They might be part of the restrictions and rules, but only in my head. They don’t seem to apply to the real world at all.”

“Exactly,” I said. “That stuff was based on purely abstract reasoning. The sort of thing that could help us get off the ground without running experiments and stuff, but isn’t very helpful if we want to explain the world around us as we live and experience it. Instead, these laws of motion can help us look at the way things move around us and set some rules or laws for motion as we observe it in the physical world.

“First, there is the law of inertia. If I don’t move this pebble, it won’t move. If the pebble is moving, it will not stop until I stop it with my hand or it hits enough air to make it stop.

“Then, the law of force. Force is the change of momentum over a period of time. Momentum is how heavy something is and how fast it is moving. This law is actually a lot more complicated than that, but we don’t have the tools we need to make use of this, so I’ll leave it at that. For now, we can use it to understand the motion of this pebble better. If the pebble is moving faster near the bottom of the slab than at the top, we can try to find the force being applied to it. The mass of the pebble hasn’t changed, but the speed has. We can’t assign numbers to this change just yet, but we can understand what that says about the force of gravity!

“And finally, the law of action and reaction. Every time an object exerts a force on another object, the second object exerts an equal and opposite force on the first object. If I push against this pebble, which means I’m applying force to it, it sort of pushes back against me and in reaction, the pebble moves forward.

“All three of these laws can help us better understand motion, which will help with motion magic. But they also help us understand other types of magic, like gravity magic. In fact, I’m probably going to make a category of magic that revolves around these principles. We can call it, physical magic!”

“That was a lot to take in all at once,” said Kelser.

“Yeah, but see how simple they each are?” I said as I let another pebble roll down the inclined stone slab. “All of those principles are inside a few experiments. We have to do a bunch of them, mostly to show how other laws might not define motion instead. And also because we don’t have something right now that Newton had.”

“What’s that?” asked Kelser.

“Mathematics,” I said. “Or more specifically, the sort of advanced mathematics we would need to truly prove something like this. At some point in the near future, I’m going to sit in a cave somewhere and scribble a bunch of mathematical proofs and equations that’ll give us the tools we need to make a lot of amazing magic happen, but right now is not that time.

“Instead, I think we can make a few simple spells based on these laws. The spells won’t be as amazing as they could be, because my belief in them won’t be completely justified, but it should be good enough for now. I can always come back to them later!”

I let another people fall down the inclined stone slab. “Okay, go grab some of those washed up branches over there. The ones by the river. Yeah, those ones. We need to start running some experiments. There’s only so much we can prove by rolling and stopping pebbles at an incline. Oh, and throw a couple of the lighter ones back into the river. We might as well start observing buoyancy as well!”