The Future is More Terrifying Than We Can Imagine
Half a century into its interstellar escape from Earth, the ship Blue Space stumbles across mysterious ruins of an alien civilization. Strangely, these ruins exist in four dimensions, one more than in our familiar world. Out of curiosity the crew halt their ship, and then make a perilous voyage across higher dimensional space to investigate.
At first the ruins remain impenetrable, until a closer inspection reveals a horrifying truth. These are the tombs of a dead race; and worse, their universe itself is collapsing. The bubble of four dimensional space that Blue Space has encountered is shrinking, falling into three dimensions.
As the ruined marvels of the long dead civilization meet the edge of the bubble they are destroyed, unable to survive in a lower dimension. Before long nothing remains; a million years of history gone forever. Shaken, the crew of Blue Space resume their flight, heading deeper into a dangerous universe.
This dark story is told in Death’s End, the final book of Cixin Liu’s Remembrance of Earth’s Past trilogy. Technologically advanced civilizations have discovered how to manipulate the laws of physics, resulting in terrible weapons of war. One of these, a weapon that alters the dimensionality of space, has horrifically destroyed the lost civilization encountered by Blue Space.
The resulting possibilities are explored through the plot of the novel. Much attention has been paid to Cixin Liu’s ideas. His Dark Forest theory, the idea that intelligent civilizations should fear each other and conceal their existence, is perhaps the best known concept of his trilogy. But another idea is in his books, one with even deeper implications.
This is the idea that the universe has been shaped by intelligence, much like how the Earth has been shaped by our own civilization. When we look up at the night sky, he speculates, we are not seeing an untouched and pristine wilderness. We are actually seeing the result of billions of years of manipulation; an artificial structure on a grand scale.
Is this an idea worth taking seriously? When astronomers look at the night sky, they try to find explanations for discoveries that are grounded in the known laws of physics. Most things can be explained through such methods, from supernova to black holes. But it is true that not everything has so far been explained.
It is also true that our knowledge of physics is still incomplete. We lack a complete theory of gravity, for example, and our laws cannot describe the interior of a black hole. Some of the strange things we see might be solved by a better understanding of nature.
But others seem better explained by something else going on. A century ago astronomers noticed that galaxies don’t spin as predicted. They introduced dark matter, a hypothetical but still undetected particle, to explain the discrepancy. Later still, astronomers found that the universe is expanding at a faster rate than expected. They invented dark energy to cover the cracks.
Other bizarre things seem to be happening. We’ve seen stars that are somehow older than the universe itself. Bursts of ultra high energy rays echo from galaxy to galaxy, again without explanation. Particles from deep space have struck our detectors, moving faster than should be possible. And strange patterns of light have been seen coming from far away stars, sparking speculation of advanced civilizations.
Most astronomers argue that all of these things will eventually be explained by physics, if only we could uncover the laws behind them. And so it may be. Other mysteries have been revealed to be rather mundane, once the right law of physics was known.
Physicists often come back to the argument that extraordinary claims require extraordinary evidence. The simplest explanation for what we see is the natural one: that things have evolved without any intelligent intervention. In the absence of any evidence saying otherwise, scientists default to this explanation, even when our current laws fall short.
In essence this is a form of caution. We don’t know the full scope of the laws of physics, and we don’t know all of the different ways in which they may manifest. Without a complete theory of nature we have no idea what the limits of the possible are. We may never truly know what they are.
This means we don’t know everything that nature is capable of. Inventing things like dark matter and dark energy is acceptable for this reason. They fill in a gap in the theories, and allow science to refine the possible explanations. But also, because we don’t know the limits of science, and therefore of engineering and technology, we don’t know what an advanced civilization could be capable of.
For some reason, though, we like to think we do. Predictions of the future invariably imagine a world based around familiar technologies, only bigger and more powerful. We apply such thinking to imagining possible alien intelligence too, as the example of SETI shows.
For decades researchers have been scanning the skies for unexplained radio signals coming from the stars. At first glance this is not an unreasonable thing to do. Radio waves were our first form of long distance communication. One can circle the Earth in mere seconds, cross the Solar System in days, and reach the nearest stars within years. If we want to talk to aliens, radio might be the way to do it.
The results have been disappointing. The astronomers hunting for signals started out optimistically. Life, they thought, should be common in the universe. But the longer the silence has lasted, the more our perceived isolation has grown. Many take this as a sign we are alone, at least in our own galaxy.
There is another explanation for the silence. Radio communications are a primitive, wasteful, technology. A century after we first mastered the technique, we’ve started moving on to better methods. Instead of radio signals, we fire laser beams down fibre optical cables. Spacecraft will soon bounce lasers across the Solar System, transferring gigabytes where radios could only manage kilobytes.
In other words, technology progressed. And though we can’t be sure how alien civilizations might develop technologically, it’s a fair bet they would discover the laws of physics in a similar way to us. Civilizations probably pass through a brief period of radio based communications before moving, like we are, on to more advanced methods.
If this is true, then it is no surprise the hunt for radio signals has come up empty handed. The astronomers looking for aliens were mistaken — they assumed that the future looked like the present. They thought, wrongly, that alien civilizations, perhaps thousands or millions of years more advanced than us, would use a technology we developed before we went to the Moon.
Earth astronomers are more like primitive tribes on an ocean island, searching the skies for smoke signals while invisible radio signals fly by. The mistake crops up over and over again. Astronomers recently scanned nearby galaxies for signs of Dyson spheres — hypothetical constructions that surround stars with solar panels to extract the maximum possible energy. They found no signs that one was ever built.
The future is not like the present. Any civilization that has the ability to build a Dyson sphere undoubtedly has more advanced ways to generate energy. Astronomers hunting for them are making the same mistake the Victorians did, believing that the future would see ever bigger steamships.
The key error in predicting the future is to assume things progress steadily and linearly. Year by year things get a bit better, a bit more efficient. But this ignores the second way in which science and technology have progressed. Breakthrough discoveries rapidly shift paradigms, suddenly offering previously unimagined ways to do things.
Relativity and quantum physics are two examples of this. Both would have been inconceivable even a decade before their discovery. Other recent trends like the Internet or mass computing could not have been foreseen with any accuracy a century ago. It is foolish, then, to think we can imagine what the 22nd Century, or the 32nd, will be like.
In Cixin Liu’s novel, advanced civilizations discover how to manipulate the laws of physics. They use this knowledge to build not only terrible weapons, such as the dimension collapsing one Blue Space encountered, but also defensive structures, which play a key role later in the book.
In doing so, these civilizations gradually shape the nature of the universe. By the time humans venture out beyond the edges of the Solar System, they find a galaxy far removed from its original, natural, condition. Could this concept also apply to the real universe?
In short, we don’t know. We don’t know what the full laws of physics permit. Dimension collapsing weapons like Liu imagines might be impossible, beyond the realm of reality, or they may be just a century into our future, permitted by some undiscovered theory of nature. Even if they are not possible, other things, so far unimagined, certainly are.
The fact that searches for alien intelligence have so far come up empty handed is almost meaningless. It means only that we have been looking for the wrong signs. Indeed, the right signs may be just in front of our noses, clear if only we could read them.
This means we cannot discount Liu’s second conclusion: that the universe is a dangerous place, potentially hostile to our existence. In a galaxy shaped by intelligence, and filled with weapons more terrible than we can imagine, drawing attention to ourselves is a risky game.
Humanity should not get arrogant, and should not forget the fragile grasp we have on existence. We should carefully reconsider plans to broadcast powerful signals to the stars, and not discount ideas of alien intelligence behind things we cannot explain. The risk is unknown, but potentially devastating.
If we do not take care, we may find that humanity is nothing more than a bug, waiting for the first powerful creature to come along and crush us.