“I have to go back to the institute to prepare for the meeting.” Lu Chenjue stood and straightened his overcoat. He looked at Shen Shuhe, a rare feeling of reluctance stirring in his heart. “It was a pleasure debating with you today, Professor Shen.”
Shen Shuhe rose as well and gave him a slight bow, a warm, spring-breeze smile brightening his refined features. “Likewise, Professor Lu. I hope this ancient library hasn’t interfered with your quantum thinking.”
Lu Chenjue walked a few steps, then suddenly stopped and turned to look at Shen Shuhe’s figure as he prepared to sit down and continue his proofreading. Under the hazy light of Beijing’s dusk, he looked even more slender and lonely. An unprecedented thought surfaced in the mind of a theoretical physicist who always acted according to carefully laid plans.
He returned to the table, took a glossy black fountain pen from his coat pocket, quickly wrote a phone number on a small yellow sticky note, and gently placed it in the corner of Shen Shuhe’s ancient book.
“If you want to learn more about how quantum equations explain human loneliness, you can contact me,” Lu Chenjue said, his voice low but carrying an undeniable firmness.
Shen Shuhe raised his head and looked at the phone number written in the sharp, decisive handwriting of someone accustomed to working with mathematical notation. He smiled faintly, a radiant smile that seemed to illuminate the library’s chiaroscuro. He picked up the sticky note and slipped it between the open pages of “Shui Diao Ge Tou.”
“I’ll consider becoming an observer and causing Professor Lu’s wave function to collapse in the near future.” Shen Shuhe lifted his brows slightly, his voice carrying a gentle, elegant intellectual provocation.
The rows of Schrödinger wave equations written in white chalk across the large blackboard at the Institute of Theoretical Physics had always been Lu Chenjue’s most constant and reliable world. Yet throughout that entire day, the mathematical notation that had once been lifeless suddenly changed shape beneath his lashes. They were no longer merely codes describing a particle’s probability density. They seemed to be vibrating to an entirely different rhythm, like the steady tapping of Shen Shuhe’s fingers against the yellowed ancient-text pages on the previous evening at dusk.
The pure fragrance of incense mingled with the breath of passing years in the ancient reading room, drifting across Lu Chenjue’s nose and drowning out the smell of disinfectant alcohol and the characteristic chill of modern laboratories. He stood before the Institute’s broad glass doors and looked out at the Beijing sky, stained lead-gray by the final days of autumn and the beginning of winter. Brilliant golden ginkgo leaves were swept away by the northern wind, spinning through the air before touching the ground, forming chaotic trajectories that no supercomputer could predict with absolute precision.
Uncertainty. Lu Chenjue murmured the word under his breath. He had spent his entire life pursuing the precision of physical laws, trying to frame the universe within perfect equations. But now he realized that a system more complex than quantum mechanics existed right beside him—a system whose wave function collapsed instantly into an entirely new state every time he tried to observe it.
He could not banish the slender, unrestrained figure of the young professor of ancient-text studies from his mind. That brief yet intellectually provocative debate was like a lone photon piercing the barrier of a double slit and creating glittering interference fringes across the still lake of his heart. For someone who always acted according to reason like Lu Chenjue, the only way to resolve this disturbance was to face it.
He reached for the ash-gray overcoat hanging on the rack and left his office. In his pocket was a note bearing several document codes related to ancient astronomical records from the Song dynasty, which he had just looked up in the internal system. It was the perfect pretext, a perfectly legitimate reason for a theoretical physicist to step into the sanctuary of ancient texts.
When Lu Chenjue gently pushed open the heavy wooden door of the Ancient Texts Library, the antique bronze wind chime hanging beneath the eaves gave a deep, muted ring. Inside, the space remained as quiet as ever, a refuge completely cut off from the hectic rhythm of the world outside. Warm golden light from a vintage desk lamp spilled across the tall sandalwood shelves that reached the ceiling, creating artistically interwoven pools of light and shadow.
In the familiar corner by the window, Shen Shuhe was bent over a stack of bamboo-slip books and faded rubbings of stone inscriptions. He wore a soft cream turtleneck sweater, his black hair falling slightly over his forehead and obscuring part of his refined face. At the sound, Shen Shuhe raised his head. Seeing Lu Chenjue approaching, his eyes curved faintly, revealing a mild smile tinged with undisguised and amused surprise.
“Professor Lu, I didn’t expect you to come back so soon.” Shen Shuhe stood and gave a slight bow, out of habit as a scholar educated in a traditional environment. “What quantum wind brought you to this antiquated place today?”
Lu Chenjue approached the reading table, removed his leather gloves, and set them aside. His voice retained its usual calm, but some of the coldness from their first meeting had faded. “I need to verify some records concerning the supernova phenomenon of 1054 in the ‘History of Song.’ The Institute of Physics’s digital database contains several translation inconsistencies in the terminology of ancient astronomy. I don’t think there’s anywhere better suited to answer that question than your reading room, Professor Shen.”
Shen Shuhe smiled softly, as if he had seen straight through the scientist’s clumsy yet prideful excuse. He gestured for Lu Chenjue to sit in the chair opposite him. “Then you’ve come to the right place. But before we begin our journey backward through time to the Northern Song, let me offer you a warm cup of tea to drive away the chill of winter in Beijing.”
With that, Shen Shuhe turned and took out an antique Ruyao ceramic tea set glazed in celadon. His fingers were slender and fair, moving with graceful precision as he scooped dry Phoenix Dancong tea leaves into a clay teapot. When pure boiling water was poured in, the leaves began to swirl and unfurl, releasing a rich fragrance of orchids and ripe fruit that warmed the air around them.
Lu Chenjue watched Shen Shuhe’s every movement intently. To a physicist, the tea-brewing process was a complex interaction between thermodynamics and molecular diffusion. Yet under Shen Shuhe’s guidance, it possessed a meditative beauty, as if time had deliberately slowed.
“Phoenix Dancong tea requires water at around ninety-five degrees Celsius. The steeping time can be neither too short nor too long.” Shen Shuhe gently pushed a small porcelain teacup toward Lu Chenjue. A thin wisp of steam rose from it, blurring the distance between them. “Please, Professor Lu.”
Lu Chenjue lifted the cup. Warmth from the ceramic passed into his palm, soothing the fingers stiffened by the cold wind. He took a small sip. The slight astringency quickly faded, leaving a deep, lingering sweetness at the back of his throat. “The tea is excellent. Thank you.”
Shen Shuhe raised his own cup as well, his gaze passing over the note of document codes Lu Chenjue had placed on the table. “You want to learn about the guest star that appeared in the first year of Zhihe during the reign of Emperor Renzong of Song, correct? The ‘Treatise on Astronomy’ in the ‘History of Song’ records: ‘In the first year of Zhihe, on the jihai day of the fifth month, a guest star appeared southeast of Tianguan, about several inches away. After more than a year, it disappeared.’ Your modern astronomers call it the Crab Nebula, the result of a brilliant supernova explosion visible to the naked eye during the day for nearly twenty days.”
Lu Chenjue was momentarily stunned by his companion’s profound knowledge and astonishing memory. He tilted his head slightly, unmistakable admiration in his eyes. “You really are full of surprises, Professor Shen. I assumed a scholar of ancient literature wouldn’t pay attention to astrophysical phenomena like these.”
“Ancient Chinese history and literature have never been separate from the starry sky.” Shen Shuhe set his cup down, his fingers gliding lightly over the wooden tabletop. “The ancients looked up at the heavens not merely to calculate the calendar, but to seek harmony between heaven and humanity. Every new star that appeared, every streak of meteoric light that flashed across the sky, was considered a whisper from the universe to the human world. To them, these were not merely masses of matter shifting through infinite space, but the flow of fate and human emotion.”
He paused, his gaze turning toward the window, where gray clouds drifted lazily past the glazed-tile roofs of the distant Forbidden City. “Speaking of the flow of emotion and time, I’ve just finished proofreading an old printed edition of Li Bai’s ‘Invitation to Wine’ from the Tang dynasty. The great poet wrote: ‘Do you not see the waters of the Yellow River descending from heaven, rushing to the sea never to return? Do you not see, in the high hall’s bright mirror, the sorrow of white hair—black as blue silk at dawn, turned to snow by evening?’”
Shen Shuhe’s voice was low, carrying the melodious cadence of ancient pronunciation, making every word and sentence fall into the quiet space with weight. As Lu Chenjue listened, a strange tremor stirred within him. The meaning of those lines immediately surfaced in his mind: *Do you not see the waters of the Yellow River flowing down from the heavens, rushing into the sea never to return? Do you not see, in the bright mirror of the hall, the sorrowful sight of white hair—black as green silk in the morning, yet turned to snow by evening?*
“Li Bai saw the passage of time as a raging waterfall that could never be reversed.” Shen Shuhe turned back to Lu Chenjue, his eyes bright with scholarly passion. “But the wonder is that he did not measure time with unfeeling numbers. The transformation from ‘green silk’ in the morning to ‘white snow’ by evening is not a physical twenty-four-hour cycle. It is a leap in emotional awareness when a person confronts the finitude of life. That emotion flows at an infinite speed, beyond the grasp of any mechanical measure.”
Lu Chenjue set his teacup on the table, the ceramic making a delicate sound against the wood. He looked directly into Shen Shuhe’s eyes. The logical thinking of a quantum physicist began to engage, but this time it was no longer dry, wrapped instead in a poetic veil of philosophy.
“Your analysis is fascinating, Shuhe.” Lu Chenjue naturally changed the way he addressed him, his voice softening slightly. The distance between them seemed to have been blown away by the warmth of the Phoenix tea. “But from the perspective of modern physics, the immeasurable flow of emotion you just described follows a rule that is deeply familiar in the quantum world. It is Werner Heisenberg’s uncertainty principle.”
Shen Shuhe raised his brows slightly, his expression filled with interest at the familiar name of one of the pioneers of quantum mechanics. He leaned forward a little, interlacing his hands over his knees. “Oh? What could a romantic poet from the eighth century and a theoretical physicist from the twentieth century possibly have in common, Chenjue?”
The way Shen Shuhe naturally took the initiative to call him by name made Lu Chenjue’s heart skip a beat. He cleared his throat softly, trying to keep his tone perfectly even to conceal the vague disturbance in his chest.
“Heisenberg proved that in the world of microscopic particles, we can never determine a particle’s position and momentum precisely at the same time.” Lu Chenjue explained, his finger tracing an invisible line across the tabletop. “If we measure it to determine its exact position at a given moment, we completely lose information about its velocity and direction of motion—in other words, its momentum. Conversely, if we know how fast the particle is moving, we can no longer know where it is. The product of the uncertainties of these two quantities is always greater than or equal to a minimum constant.”
He looked into Shen Shuhe’s attentive eyes, his warm, deep voice steady. “I think the human mind and emotions form a quantum system of their own. When you try to define, name, and frame an emotion at a specific moment—for example, asking yourself, ‘How deeply am I in love?’ or ‘How profound is this sadness?’—you’re trying to measure its ‘position.’ But the instant you obtain that quantitative answer, you’ve inadvertently extinguished its ‘momentum,’ freezing the natural flow of emotion and stripping it of its original vitality. The more precisely you try to define one side, the more vague and chaotic the other becomes.”
Shen Shuhe listened in silence, his gaze wavering like the surface of water in the teacup. Lu Chenjue’s explanation was not at all dogmatic. Instead, it opened an entirely new dimension through which to decipher the mysteries of the human soul—mysteries that had long been described only in the abstract language of poetry.
“The harder you try to measure position, the more momentum disappears…” Shen Shuhe repeated softly, a knowing smile appearing on his refined face. “So that’s how it is. Li Bai never tried to measure time or define his sadness. He allowed himself to drift with the maximum momentum of emotion, accepting complete uncertainty about his own position in the flow of history. That is why his poem possesses such enduring power, moving millions of hearts across thousands of years. Because he never caused his own emotional wave function to collapse.”
“Exactly.” Lu Chenjue nodded slightly, his eyes now filled with profound indulgence and empathy as he looked at Shen Shuhe. “Uncertainty isn’t a flaw in measurement. It is the fundamental nature of reality. Human beings are the same. It is precisely the hazy spaces and nameless gray areas within the soul that create the beauty and richness of life. If everything could be calculated and predicted with absolute precision, like a classical mechanical trajectory, how cold and frightening this world would become.”
“I never thought I’d live to hear a theoretical physicist praise ambiguity.” Shen Shuhe teased him, his smile as radiant as morning sunlight breaking through the fog. He raised his teacup toward Lu Chenjue. “To our uncertainty, Chenjue.”
Lu Chenjue raised his own cup and lightly tapped it against Shen Shuhe’s. The delicate chime of ceramic sounded through the silent space, like an affirmation of the special connection quietly taking shape between two souls that belonged to entirely different worlds.
While the atmosphere in the corner of the ancient reading room was immersed in a profound harmony of intellect and emotion, an entirely different kind of encounter was unfolding in the library’s outer foyer—with a rhythm that was noisy, energetic, and thoroughly experimental.
Qin Zhao, an associate professor of experimental physics at the Institute of Theoretical Physics, stood before the librarian’s desk with a bright, somewhat roguish grin. He wore a striking neon-blue puffer jacket, utterly at odds with the solemn atmosphere of the Ancient Texts Library. His goal today was not to search for any mathematical equation, but for the cold librarian sitting behind that computer.
Wei Lan, the librarian in charge of the special-restoration book section, was typing intently. He wore a crisply pressed white shirt beneath an ash-gray vest, his refined face as cool and distant as a statue carved from jade. Qin Zhao’s appearance was like an impurity tossed into a supersaturated solution, immediately drawing a slight frown from Wei Lan.