Chapter 18: The Laws of Motion: A New Foundation

A month later.

Inside Lia’s room, the air grew noticeably warm.

A sphere of reddish-orange flame hovered silently before her outstretched small hand, burning without a whisper of sound.

Klein stood nearby.

“The energy output is stable, but the model’s structure still has redundancies. The psychic nodes forming the constraint field could be further streamlined.”

Lia’s psychic energy swiftly adjusted the ‘Elemental Fireball’ spell model within her mind.

She deleted several non-essential structural connection points and re-routed the energy flow path.

The surface of the hovering fireball rippled faintly, its volume shrinking slightly, yet its light became even more concentrated.

The room’s temperature rose once more.

“Excellent.” Klein’s voice betrayed little emotion. “Next, ‘Force Field Shield’.”

Lia dispelled the fireball, then began constructing a new model in her mind.

This arduous training had persisted for a month, spanning from the most fundamental actions of pushing, pulling, burning, and freezing, to the more intricate arts of shaping and defending.

She absorbed the magical knowledge of this world like a sponge, with an almost frenzied intensity.

Adèle pushed the door open and entered.

“Master, Archmage Edgar has arrived.”

Klein looked at Lia.

“The training will pause for now. Come with me.”

Lia followed Klein down the stairs and into the reception hall on the first floor of the tower.

A man with light golden hair stood by the window; he turned around, first noticing Klein, then Lia behind him.

The golden-haired man’s gaze settled upon Lia.

“This must be Lia, I presume. I’ve read your thesis; it was exceptionally well-written.”

“Greetings, Master Edgar.” Lia bowed slightly.

“Please, have a seat.” Klein gestured.

The three took seats around the long table.

Edgar dispensed with pleasantries, placing a thick leather scroll case on the table, untying its straps, and unfurling its contents.

It was a lengthy parchment, densely covered with data and illustrated with several structural diagrams.

“Following your line of thought, I conducted some new experiments,” Edgar said, his finger tapping the diagram. “To eliminate the influence of air resistance, I constructed a vacuum tube one hundred feet deep.”

Lia’s attention was immediately captured.

A vacuum experiment?

Had this world’s technological prowess advanced to such a degree?

“I used alchemy to evacuate the air from it, then allowed different objects to fall within. The results were entirely consistent with your thesis: constant acceleration.”

Edgar’s expression remained calm.

“However, I did encounter a problem.”

He pulled another chart from the scroll case.

“I increased the tube’s height to three hundred feet. Within the range of one hundred to three hundred feet, I repeated the experiment a thousand times, utilizing the highest precision timing array.”

“I discovered an extremely subtle attenuation in the value of acceleration ‘a’.”

Klein’s blue eyes scanned the chart.

“What was the magnitude of the attenuation?”

“From the ground to three hundred feet in altitude, the value of ‘a’ decreased by roughly three ten-thousandths. This figure is so minuscule it’s almost negligible, yet it undeniably exists.”

Edgar looked at Klein, then at Lia.

“This confirms our previous hypothesis: the field generated by the earth does indeed attenuate with distance. It’s just that within the near-ground range, this attenuation is extremely slight.”

“But this presents an even greater paradox,” Edgar’s voice deepened. “Why does the celestial field attenuate so drastically, while the terrestrial field remains almost constant?”

“The sun’s field is potent enough to pull planets millions of miles away. Yet the earth’s field shows almost no change at a mere three hundred feet. Are these two types of fields truly the same phenomenon?”

Silence descended upon the reception hall.

This was an impasse.

“I have a new theory,” Edgar said, breaking the silence.

He produced a fresh parchment, upon which a complex model was drawn: a colossal sphere representing the world, its surface enveloped by a ‘membrane’ composed of countless arrows.

“I call this the Aether Pressure Theory.”

“Our world, rather than existing in a vacuum, is immersed in a medium called ‘aether’. As the world moves at high speed through this aether, the aether exerts a pressure upon its surface.

This pressure is the source of gravity. It propels all objects towards the area of greatest pressure, which is the ground.

The aether is not uniformly distributed. The further one is from the ground, the rarer the aether becomes, and the less pressure it exerts. This explains why acceleration ‘a’ attenuates with altitude.”

Lia gazed at the diagram, remaining silent.

Klein studied the diagram, pondering for several seconds.

“If pressure exists, then its effect on an object should be related to the object’s frontal area. A feather and a lead sphere, even if they possess identical mass, should experience entirely different pressures.

Yet experiments have proven that acceleration is independent of any object’s properties.”

With a single statement, Klein pinpointed the theory’s most fatal flaw.

The confidence on Edgar’s face vanished.

“Indeed. Universality.” He shook his head with a bitter smile. “That cursed universality.”

He had spent a month researching, expending enormous resources to construct a three-hundred-foot vacuum tube, only for the data he obtained and the theory he proposed to ultimately lead him back to square one.

He simply could not explain why this influence affected all objects in precisely the same way.

Silence once again filled the reception hall.

Sunlight streamed through a high window, casting a bright band across the long table, where dust motes danced and shimmered in the air.

“Lia.”

Edgar suddenly spoke, turning his gaze to the quietly observing girl.

“Your thesis was the genesis of this entire inquiry. Do you have any thoughts on this predicament?”

Klein’s gaze also shifted towards her.

Lia looked up, meeting the eyes of the two preeminent mages.

The knowledge within her mind far surpassed the understanding prevalent in this world.

She had merely presented a result, without providing the complete logical framework for its derivation.

Now, they were stuck, and the key to moving forward lay firmly in her grasp.

“Master, Master Edgar.”

Lia stood, her small frame appearing even more petite before the oversized chair.

“Perhaps, from the very beginning, we have been asking the wrong question.”

Neither Edgar nor Klein spoke, simply observing her intently.

“We have consistently asked what makes an object fall.”

“But we have never asked what would happen if nothing were making it fall.”

Edgar’s brow furrowed, seemingly trying to grasp the meaning of her words.

“If an object were subjected to no influences whatsoever, what would its state of motion be?” Lia continued to inquire.

“Stillness,” Edgar replied without hesitation.

This had been the consensus among scholars since antiquity: stillness was the natural state of the world, and motion required an impetus.

“What if it were already in motion?” Lia pressed.

“It would gradually come to a stop,” Edgar’s answer remained self-evident.

“Why would it stop?”

“Because… whatever propelled it would have ceased.”

“But what if nothing impeded it? For instance, on an absolutely smooth surface, with the air also removed.” Lia described an idealized environment. “If I were to give it a push, what would happen?”

“It would… keep moving indefinitely?” A hint of uncertainty crept into Edgar’s tone.

Klein’s gaze sharpened.

“Precisely.” Lia offered a definitive answer. “When an object is subjected to no external influences whatsoever, its state will not change. If it is at rest, it will remain at rest. If it is in motion, it will continue to move at the same speed, along the same straight line, indefinitely.

This is the true starting point of everything.

The inherent nature of an object is not stillness, but the preservation of its current state.”

These words struck Edgar like a bolt of lightning, cleaving through the fog in his mind.

He stared blankly at Lia, his mouth slightly agape, yet utterly unable to utter a single word.

This perspective completely overturned his fundamental understanding, and indeed, the centuries-old basic knowledge of this entire world.

“Therefore, we should not ask why an object is in motion, but rather why an object’s state of motion changes.”

Lia’s voice resonated through the quiet reception hall.

“Whatever causes an object to fall is not imparting motion to it, but rather altering its motion.

It transforms an object at rest into an object undergoing accelerated motion.

This change, then, is the core of what we need to investigate.”

Klein watched Lia, his hand subtly clenching beneath the table.

“To comprehend this change, we first need to establish three fundamental laws.”

Lia extended a single finger.

“The first, as we just discussed, is the law of maintaining status quo. I call it the Law of Inertia.”

She extended a second finger.

“Second, to alter an object’s current state, an action must be applied to it. The greater this action, the faster its state changes. I call this ‘force’. And the rate at which its state changes is acceleration. Thus, we can derive a formula to describe the relationship between force, a certain property of the object, and acceleration.”

She extended a third finger.

“Third, action is not unidirectional. When I push a wall, the wall also pushes me. The earth pulls a stone downwards, and the stone, in truth, also pulls the earth.”

“I call this the Law of Interaction.”

“Inertia, force, interaction.” Lia looked at the utterly bewildered Edgar and the now intensely serious Klein. “These three laws are the cornerstone of all laws of motion.”

“For they can explain not only why objects on the ground fall. But also why the stars in the heavens revolve.”