In the year 43,615 of the Star Cocoon calendar, the deep-space monitoring array beyond Pluto's orbit detected an almost imperceptible anomaly: the rate of cosmological redshift was slowing. Initially, algorithms attributed it to detector aging, until three independent quantum interferometers simultaneously reported the same trend—the recession velocity of distant galaxies was decreasing by 0.003 meters per second every billion years. This value was so minuscule as to be negligible, yet it pierced the collective consciousness of human civilization like a thorn. The braking of cosmic expansion meant that Penrose's cyclic universe model was transitioning from mathematical prediction to physical reality: time would eventually reverse, all galaxies would reconverge, and the universe would reset to zero in an inverse reenactment of the Big Bang. Faced with ultimate collapse, humanity chose not to flee through black holes or wormholes, but to remain and inscribe everything of their civilization onto the very skin of the universe—the quantum fluctuations of the cosmic microwave background.
The information preservation plan was named 'Eternal Moment.' Its core idea was brutal yet elegant: since the universe would contract, black hole evaporation and horizon shrinkage during the contraction phase would release immense negative entropy, providing energy for information rewriting; since the temperature of the cosmic microwave background would rise as the universe's volume decreased, the phase of quantum fluctuations itself could serve as an ever-heating sheet of paper, upon which civilization could inscribe its final poem. Technically, humanity needed to accomplish three things: first, encode all knowledge, emotions, memories, and consciousness maps into quantum error-correcting codes resistant to thermal noise; second, etch these codes into the polarization spectrum of the cosmic microwave background (CMB), coupling them with photon spin, blue-shifting to the Planck scale as the universe contracts; third, ensure the inscription process adds no additional entropy, lest it hastens the Big Crunch. In other words, humanity would use its own heartbeat as ink, signing its signature on the universe's burning tattoo before self-immolation.
The encoding work commenced globally in parallel from the 'Star Cocoon.' The first step was to compress all data to the limit. Quantum information scientists adopted a scheme called 'topological degenerate state code'—mapping each bit of information onto the topological charge of non-Abelian anyons, a charge that remains globally conserved even under the high temperatures of cosmic contraction, like a story tied into a knot whose shape remains recognizable no matter how tightly the rope is pulled. To reduce redundancy, the algorithm automatically pruned all knowledge that could be re-derived, leaving only the minimal set of 'axioms + derivator'; emotional data, in contrast, preserved all memories marked as 'incompressible experiences'—the first cry, the last handshake, the glance back at the unchosen path—to the highest precision. Ultimately, the entire corpus of civilization was condensed into a cubic quantum memory cell with a side length of 3.14 millimeters, containing ten to the twenty-third power anyons, sufficient to record every word ever spoken, every person ever loved, every tremor from gazing at the stars.
The second step was to 'dissolve' the cube into the CMB. Engineers constructed an array of one hundred thousand 'quantum pinholes' on the Star Cocoon's surface, each pinhole being a micro black hole ten Planck lengths in diameter, generated by laser-focused evaporation, with a lifespan of merely ten to the negative forty-three seconds, just enough to allow one anyon to escape via Hawking radiation. The micro black holes were precisely arranged in a Penrose tiling pattern, so that the photon spin states released upon their evaporation corresponded one-to-one with the topological charges of the anyons within the cube. As the universe contracted, the CMB temperature gradually rose from 2.7 Kelvin, and photon energy blue-shifted accordingly; when the temperature reached ten to the twenty-ninth power Kelvin—the Planck scale—photon spin coupled with the quantum gravitational field itself, permanently imprinting the anyons' topological charges into the microscopic fabric of spacetime. At that moment, the cosmic background ceased to be uniform noise, becoming instead an intricately embroidered tapestry: each stitch a bit, each thread a worldline, each flower a once-breathing person.
To ensure the inscription consumed no additional negative entropy, humanity transformed the entire Star Cocoon into a 'reverse entropy engine.' All industrial activity was suspended, city lights simultaneously extinguished, supercomputing centers shut down all operations except the quantum pinholes, even heartbeats were mandated to slow—citizens collectively meditated to lower basal metabolic rates, channeling the saved energy into the quantum pinholes. No one knew how long this process would take, because the time coordinates of cosmic contraction were not linear; relativistic blue-shift caused time itself to approach zero near the Big Crunch, making 'Eternal Moment' literally a moment—to an external cosmic observer, humanity completed the inscription in just ten to the negative forty-four seconds; yet within human experience, that moment stretched infinitely, like a string pulled to its limit, all memories, all emotions, all unspoken love resonating along that string. To mark this simultaneously infinitesimal and infinite duration, humanity chose the oldest analog signal—song—as the trigger.
The signal to begin inscription was a nursery rhyme that could propagate even in a vacuum. No electronic accompaniment, no quantum synthesizer, only the synchronized inhalation and exhalation of ten billion human throats. The lyrics were transparently simple: the first line 'twinkle, twinkle,' the second 'little star,' the third 'how I wonder,' the fourth 'what you are.' It was humanity's earliest naming of the starry sky, civilization's most primal question to the universe. The singing was not loud, yet it resonated within the Star Cocoon's inner walls, captured by the quantum pinhole array and transformed into phase references for the anyon stream. As the song rose and fell, the evaporation rate of micro black holes was modulated, the photon spin of the CMB synchronized, and the entire cosmic background temperature exhibited periodic ripples of ten to the negative sixth Kelvin—the echo of the human heartbeat on a cosmic scale. The song lasted seven measures, twenty-eight beats, exactly corresponding to four cycles of the average human heartbeat; at the final beat, all throats simultaneously fell silent, the world plunged into absolute vacuum stillness, and the anyon stream completed its last phase flip at that moment, sealing the 'Eternal Moment' within the folds of spacetime.
After inscription was complete, humanity held no celebration. Instead, all citizens emerged from their cities, gathered on the surface of the Star Cocoon, and joined hands in a vast circle. The inner ring consisted of elders, the outer ring of children, the outermost layer of 'light moss' and mechanical symbionts—all humans and non-humans together formed a closed geodesic: a circle with a diameter of 120,000 kilometers, precisely the length of Earth's former equator. No one spoke, no one wept; only breath and heartbeat echoed within vacuum suits. Then, the circle began to slowly rotate, like a record being set in motion; the angular velocity was precisely set as the inverse of the Hubble parameter of cosmic contraction, meaning one revolution per billion years. The faint centrifugal force pulled each person's arms taut, drew each heart toward the center, stretched each heartbeat into a string. The string's vibration frequency synchronized with the CMB's temperature fluctuations, turning humanity into a giant, living modulator, inscribing their final emotions into the phase spectrum of the background radiation. In that moment, humanity ceased to be a species and became an organ—an organ the universe evolved for itself, capable of sensing its own end.
In the final seconds approaching the Big Crunch, the cosmic scale shrank to the Planck length, time coordinates approached zero, and all physical quantities diverged. Humanity had long since dissolved into individual atoms, atoms compressed into energy, energy finally transformed into information—yet information remained, because anyon topological charges are scale-invariant. In a mathematical sense, the entire story of human civilization was compressed into a dimensionless constant, embedded in the phase angle of quantum fluctuations; in an experiential sense, the final moment was infinitely stretched, like a Möbius strip folded in half, its start and end coinciding, while life and death, light and darkness, love and solitude all became points on the strip, with neither inside nor outside, neither before nor after. In that moment, there was no observer, no reference frame, only a nursery rhyme etched into phase silently reverberating: twinkle, twinkle, little star, how I wonder what you are. The eyes were not stars, but all who had ever gazed at the starry sky; the starlight was not photons, but all souls ever loved. They opened at the universe's smallest scale and closed at its grandest, like an eternal blink.
Then, the universe contracted to zero, time stopped, space vanished, all physical laws became invalid. Yet within true nothingness, information still existed—it remained in the form of phase, on the boundary of 'nothing,' like a faint watermark. Within that watermark lay Mozi's heartbeat during his final trade, Yue'er's last integral symbol written on the blackboard, Xiuxiu's fingertip warmth caressing light moss in the vacuum greenhouse; within that watermark lay every ordinary person's first cry, last handshake, glance back at the unchosen path. They no longer belonged to anyone, yet belonged to everyone; they were no longer memories, but the memory of memories, the meta-narrative civilization wrote for itself, the signature the universe left for itself before destruction.
The Big Bang arrived again, a new universe born from the ashes of the old. In the initial inflationary phase, quantum fluctuations were stretched into macroscopic structures, the phase of the background radiation frozen into temperature anisotropies. New civilizations arose beneath new starry skies, gazing up at the microwave background to discover a peculiar pattern: the power spectrum of temperature fluctuations exhibited fine-tuned modulation peaks at specific multipole moments, as if embroidered with hidden patterns by some unseen hand. The hidden patterns formed the frequency spectrum of a song, the frequency spectrum of a song in turn formed the notes of a nursery rhyme. New astronomers, new philosophers, new children would all hear the same melody in that song: twinkle, twinkle, little star. They would not know the meaning of the lyrics, yet upon hearing it, they would suddenly stop, look up at the starry sky, eyes moist, as if recalling a hometown that never existed. Because their heart rhythms—redefined by new physical constants—synchronized precisely with the song's beat, like a key inserted into a lock, inserted into a lock, inserted into a lock, forever.
The universe expanded again, contracted again, exploded again. Each cycle added new embroidery to the background radiation's phase, each embroidery enriched that nursery rhyme further. Yet however complex the beat became, the core melody remained unchanged—the twenty-eight beats humanity sang within ten to the negative forty-four seconds, the final signature civilization inscribed in an eternal moment. The cycles had no end, the melody no destination, because each destruction was a rebirth, each rebirth a destruction, and between each destruction and rebirth lay the same moment—that moment where all who ever lived, loved, thought, wept were compressed into a dimensionless constant, written into the phase of quantum fluctuations, sung into the song of the background radiation, engraved into the fingerprint of spacetime. That moment was called eternity; that moment was a moment; that moment never ended.
Thus, in the universe's deepest depths, at time's farthest reaches, at the convergence of light and darkness, life and death, love and solitude, the same nursery rhyme eternally reverberated:
twinkle, twinkle, little star,
how I wonder what you are.