Chapter 131: Research Progress

The astrophysicist’s voice echoed in Hua Feng’s mind. Although he seemed to know a little about many things, his understanding was in fact far removed from reality.

According to international media reports, dark matter is one of the most elusive components of the universe, and scientists are striving to find the latest evidence to align with mathematical models of space. Yet, to this day, humanity remains unable to directly see or detect its traces. Physicists believe this mysterious substance fills the vast voids of the universe, while matter like planets and stars composes only a small fraction of the whole. However, a new study suggests that adding a small amount of dark matter to a supermassive black hole could create one of the strangest objects in the cosmos: a wormhole. Wormholes are the stuff of science fiction, described by theorists as tunnels through spacetime that can connect two distant points in the universe.

Dr. Konstantinos Dimopoulos, a physicist at Lancaster University, explains that in the centers of some galaxies, dense distributions of gas and dust around a supermassive black hole become extremely bright, emitting intense light and heat. Powerful magnetic fields ejected from the black hole then influence the properties of dark matter. As the turbulent galactic core churns, Dr. Dimopoulos suggests that a specific type of dark matter—axions—will be affected. These antiparticles are thought to exist throughout the universe, interacting weakly with one another and contributing to the formation of galactic structures, much like an invisible mist permeating the galaxy.

Dr. Dimopoulos states that when this matter concentrates at the churning center of a galaxy, intense vortex-like magnetic fields cause strange effects, effectively switching it to a state of negative energy. When this dark matter appears around a supermassive black hole at the galactic center, three elements—the supermassive black hole, the spiral magnetic field, and the axion dark matter—can combine to form a wormhole. Dr. Dimopoulos notes that the emergence of negative-density matter alongside strong magnetic fields could force the appearance of a wormhole at the center of an "active galactic nucleus." He adds that the transition of a supermassive black hole into a stable wormhole could have profound implications for how the surrounding galaxy is formed and how galaxies interact.

Unlike black holes, wormholes could theoretically be one-way or two-way, allowing matter to be ejected from one region of the universe to another. Due to the singularity of a supermassive black hole, a wormhole would be a point where the universe curves infinitely. Because of the negative density of the antimatter, it would cause axions to be "transformed" by the magnetic field, exerting a massive influence on the surrounding galaxy. Dr. Dimopoulos posits that if dark matter consists of axions, an advanced civilization could potentially generate artificial spiral magnetic fields with specific properties to alter local dark matter, perhaps creating a wormhole. This could become a means to achieve interstellar or even spacetime travel.

Exploring the starry sky has been an eternal dream of humanity. On clear nights, whenever we look up, we see a sky full of stars. Since ancient times, the starry expanse—with its incomparable vastness, depth, beauty, and mystery—has stirred countless reveries in the human heart. The famous American science fiction series *Star Trek* contains a short yet infinitely meaningful prologue: "Space, the final frontier." When I first watched this television series, this prologue, recited in a magnetic voice-over, left a mesmerizing impression on me.

In ancient times, humanity explored the stars with the naked eye; later, we began using telescopes. However, humanity’s first step toward the stars occurred in 1957, when the first human-made spacecraft finally flew beyond the atmosphere of our blue planet. Twelve years later, humanity left its footprints on the moon.

Three years after that, humanity launched the Pioneer 10 deep-space probe toward the outer solar system. In 1983, Pioneer 10 flew past the orbit of Neptune, becoming the first human-made spacecraft to leave the solar system.

In the mere twenty-some years since the launch of the first spacecraft, Konstantin Tsiolkovsky’s prediction that "humanity will first cautiously pass through the atmosphere, and then go on to conquer the entire space around the sun" became a reality. Humanity’s pace in exploring the stars could certainly be called rapid. Yet, relative to the endless starry sky, this pace remains far too slow. Pioneer 10, the first to fly out of the solar system, is currently gliding through a cold, silent void. Among the myriad stars, how many years will it take to reach the next sun? The answer is two million years! By then, it will arrive at Taurus, sixty-eight light-years away.

A distance of sixty-eight light-years is enormous by any terrestrial scale, yet it is undoubtedly insignificant compared to the center of the Milky Way, located thirty thousand light-years away, the Andromeda Galaxy at 2.2 million light-years, the Virgo Cluster at sixty million light-years, and other even more distant celestial bodies. Human curiosity has no boundaries, but even if the speed of human spacecraft were many times faster, or even approached the physical limit of the speed of light, it would still be agonizingly slow when measured against the distances of interstellar space.

Is there any way to allow a spacecraft to bypass the speed limit in some way, thereby crossing those near-infinite distances in a very short time? Science fiction writers were the first to spread the wings of their imagination.

In 1985, the renowned planetary astronomer Carl Sagan of Cornell University wrote a science fiction novel titled *Contact*. Sagan had a deep interest in exploring extraterrestrial intelligence; one of his purposes in moonlighting as a science fiction writer was to raise funds for the SETI project, which seeks extraterrestrial intelligence. His novel was later adapted into a film, earning him widespread fame.

In his novel, Sagan recounted a moving story: a female scientist named Ellie receives a series of radio signals from an extraterrestrial intelligence. Through research, she discovers that these signals contain instructions for building a special device that would allow humanity to meet the senders. After great effort, Ellie and her colleagues successfully built the device and, through it, crossed the vast interstellar space to achieve first contact with extraterrestrial intelligence.

But what method did the device, built according to the instructions provided by the extraterrestrial intelligence, actually use to allow the traveler to cross the vast interstellar distances? This was where Sagan needed to "fantasize" boldly. His initial idea was to use a black hole. However, Sagan was not an ordinary science fiction writer; his scientific background made him want his fiction to contradict known physical laws as little as possible.

Thus, he called his old friend, Professor Kip S. Thorne of the California Institute of Technology. Thorne was an expert in gravitational theory, and Sagan asked him to provide a technical evaluation of his idea. After thinking and making rough calculations, Thorne quickly told Sagan that black holes could not be used as tools for interstellar travel; he suggested that Sagan use the concept of a "wormhole." To my knowledge, this was the first time the term "wormhole" entered science fiction. Since then, various novels, films, and television series have adopted the term, and it has gradually become a standard term in science fiction stories. This was the fruit of a small exchange between a science fiction writer and a physicist.

The exchange between Sagan and Thorne not only brought a brand-new term to science fiction but also pioneered a new field of research in physics. In physics, the concept of the wormhole was first proposed by C. W. Misner and J. A. Wheeler in 1957—the very same year humanity launched its first spacecraft. So, what exactly is a wormhole, and why is it regarded by science fiction writers as a tool for interstellar travel?

Let us illustrate with a simple example: as everyone knows, on the surface of an apple, traveling from one point to another requires following an arc. But if a worm bores a hole between those two points, one can travel in a straight line through the wormhole, which is clearly shorter than the original arc. Extending this analogy from a two-dimensional apple surface to three-dimensional physical space yields what physicists call a wormhole. It is this characteristic of wormholes forming a shortcut between two points that makes them so beloved by science fiction writers.

As long as a suitable wormhole exists, no matter how distant a place may be, it could become within reach. Interstellar travelers would no longer be constrained by the vastness of spatial distance.

In some science fiction stories, highly technologically advanced civilizations use wormholes for interstellar travel just as we use highways to travel between towns today. In the famous American science fiction film and television series *Stargate*, humans use a device left on Earth by an alien civilization—called a "Stargate"—to establish wormhole connections with many other "Stargates" on distant planets, thereby being able to transport people and equipment to those remote worlds almost instantaneously. The wormhole has become a paradise for interstellar travelers in science fiction.

However, the wormholes proposed by Misner and Wheeler were extremely tiny and would disappear in a very short time, making them incapable of serving as channels for interstellar travel. After the publication of Sagan’s novel, Thorne became deeply interested in wormholes and began an in-depth study of them with his student, Mike Morris. Unlike Misner and Wheeler, Thorne was interested in wormholes that could serve as channels for interstellar travel; such wormholes are known as "traversable wormholes."

It is unknown when such time travel might become reality, a thought shared by both Hua Feng and Yun Meng.