"How come?" Chris asked.
"Because of air resistance," Kyraia explained.
"Air resistance?"
"Yes. It is called air resistance. It is the invisible friction from the air that naturally slows down any moving object." Kyraia continued her lesson. "It does not matter how high you shoot the rock into the sky. Even if you shoot the rock ten kilometers high, the air resistance will cancel out the rock's acceleration when it falls. When the rock finally hits the target, the impact is already weakened."
Kyraia crossed her arms. "Air resistance is the reason why attack magic like fireballs and ice magic are shot in a straight line toward the target rather than shooting upward to create an arc. Shooting in a straight line will inflict more damage than shooting upward."
Chris pleaded desperately. "But... when I was shooting from the hill, I swear the arc shot caused more damage than the straight line shot. I am telling the truth."
Kyraia hummed thoughtfully.
"Describe the rock you used," she requested.
"That rock?" Chris thought back. "Let me see. I remember the rock I used was incredibly heavy. It was heavier than normal rocks. I thought the rock was strange at that time."
Kyraia's eyes widened slightly. "That rock probably contained heavy minerals inside. If that is the case, it changes everything. A heavy rock has high density. If you really used a heavy rock to slingshot upward, then wind resistance will be lessened significantly. The heavy rock will be more destructive if shot upward to arc than by shooting in a straight line."
Chris's face brightened immediately upon hearing her validation.
Kyraia saw a small rock sitting about one meter away from her on the pavement. Chris followed her gaze. Kyraia raised her right hand and chanted a few strange words. The small rock suddenly floated. Chris's eyes widened in sheer surprise.
"It is called floating magic," Kyraia explained smoothly.
Kyraia created a small Aura Tail on the opposite side of the rock to push it forward toward her. The Aura Tail is created because the rock needs something to make it move forward.
The movement of the rock happened in a specific sequence. First, it moved vertically to float in the air. Then, when the Aura Tail was created, it moved toward Kyraia's right hand to take a perpendicular line.
If Kyraia raised her right hand and the rock simply moved diagonally from the ground toward her palm without a Tail, then that would be telekinesis. Using the power of the mind to control a rock's movements is telekinesis. But Kyraia used floating magic here, and she created an Aura Tail to make the rock move.
Kyraia's right hand caught the rock perfectly. Chris's eyes sparkled brightly because it was his very first time seeing real magic.
"Miss Kyraia," Chris gasped. "That was amazing. What was that glowing yellow light?"
Kyraia's eyes widened in profound shock. "You can see the glowing light?"
Chris nodded eagerly.
"That is impressive," Kyraia said. "Not everyone can see that glowing light. That yellow light you saw is called Aura."
Before Chris could ask anything further about Aura, Kyraia placed her right hand about five centimeters above the ground, and she dropped the rock.
CLACK.
Chris's focus shifted to the sharp sound of the rock hitting the cobblestone.
"The reason why the rock hit the ground is the force called gravity," Kyraia said. "If a rock falls to the ground, it creates an impact."
She picked up the rock and lifted it to her knee level. She opened her hand, and the rock fell with a much louder sound than the five-centimeter drop.
CRACK.
She picked the rock up again and raised it to her chest level while she sat on the bench. She let go of the rock, and it fell once more.
SMASH.
"The higher it goes, the stronger the impact," she stated. She picked it up again, lifted it to her head level, and let it go.
BANG.
Kyraia raised her right hand, and Chris saw the rock on the ground covered entirely in a yellow Aura. Kyraia chanted a floating spell, and the rock floated. She built an Aura Tail at the bottom of the rock. The rock flew fast and high, reaching ten meters up into the sky. It hovered in the air while glowing in a bright yellow Aura. The upward movement of the rock began to slow, and then it plummeted. It fell with a deafening sound.
BAAAAM!
Chris looked closely and saw a tiny crack on the cobblestone caused by the impact. It was not an obvious crack, but it was completely visible if someone looked closely.
Kyraia started talking again. "That's how gravity works. The higher the rock is, the heavier the impact because the falling object gains more speed the longer it travels downward."
Kyraia looked at Chris. "If we use a heavy rock to throw high into the sky, it will bypass the air resistance. Let us compare the straight line shot and the arc shot. For example, you have a slingshot. You use a heavy rock that bypasses air resistance against a target sitting twenty meters away on a flat surface. If you shoot directly straight, it will deal more damage than if you perform an arc shot. But there is a catch. If you are on high ground, just like you said you were on a hill, then this is where everything changes. When you shoot from a high place, the arc shot allows the heavy rock to fall from a much greater height, so gravity has more time to pull it down and multiply the crushing force."
Kyraia continued her lesson. "Let us take the experiment to the next level. A high-level Mage can shoot around three hundred meters in distance before the Aura Tail loses its power. Let us take for example an Earth Mage who floats a heavy rock that defies air resistance, and he shoots it toward a giant monster at one hundred fifty meters distance. It will inflict normal damage to the monster. Then another Earth Mage uses the exact same kind of heavy rock, but he does not shoot it directly toward the monster. He shoots it upward to create an arc, so it reaches about three hundred meters above the ground. If that heavy rock reaches the giant monster, it will cause bigger damage than the first attack that was shot in a straight line because the massive height allows gravity to accelerate the heavy rock into a devastating, unstoppable meteor."
Chris smiled widely. "So does that mean the Blue Star is possible because the arc shot works?"
Kyraia shook her head firmly. "No. Because the Blue Star in that comic book is made up of magical energy. And magical energy has almost zero density. Remember when I said even a rock will not work unless it is truly heavy. If an ordinary rock will not work, the ball of energy will be worse because the ball of magical energy has almost no mass."
Chris screamed loudly. "What do you mean? What is mass?"
The people walking nearby heard the scream and quickly turned their heads. Kyraia was shocked by the sudden outburst, but she calmly thought of a way to explain the term to a small kid.
"Mass means how heavy something is, so in other words, the ball of energy is weightless," Kyraia explained. "If you throw a weightless object into the sky like a feather or a balloon, the wind easily catches it. When it finally descends, the air resistance will completely block the momentum. When it hits the target, the impact decreases significantly. The impact caused by a straight line shot is far more destructive in this case. Arcing will only work if you shoot a heavy object into the sky, but it will not work with weightless objects like a ball of energy."
Chris shouted angrily. "That can't be!"
If Kyraia was just a regular person, she could have lied to comfort the kid who wanted to live in his fantasy. But Kyraia was a magic researcher. It went against her principles to tell a beautiful lie, especially if it was about magic.
Kyraia leaned closer to him. "I am sorry, Chris, but it is the truth. The Blue Star is just fiction. It is not real. This comic book tells you a lie."
Chris gritted his teeth. "You are lying!"
Chris turned and ran away as fast as he could. Kyraia attempted to reach the young boy's shoulder, but he was unbelievably fast. He left her right hand floating uselessly in the air. Her jaw dropped slightly, and a heavy guilt washed over her because she had just made a little kid cry.
Suddenly, a strong gust of wind blew across the street. The wind lifted her tall hat, but she managed to catch the brim before it flew away. Her silver hair waved wildly as the strong wind blew.
The sudden breeze pushed the hair completely back from the sides of her face. It revealed Kyraia's pointy ears, an undeniable trademark of elven lineage.