The one, p.30
The One, page 30
Yet, after quantum mechanics has revealed its monistic foundation, and after scientists have started readily employing it in their search to make sense out of matter, space, and time, there are still open questions left: What is this “One” that we advocate as a foundation of nature? How is it related to the monistic beliefs of the ancients? What does it imply for the traditional approach to decomposing the universe into particles or strings? What does it mean for us as human beings to live in a monistic universe? And finally, can we be sure it is correct? Or could it possibly be wrong?
What Is “The One”?
At the verge of “quantum supremacy”—the moment where quantum computers outperform classical computers—the real hardware of quantum computing remains a mystery. One hundred twenty years after Max Planck’s original quantum hypothesis, there is still no consensus about what quantum mechanics actually is about. If this book is right, quantum mechanics deals with “the One,” an ancient philosophical concept that integrates all that possibly could happen—a three-thousand-year-old idea that has accompanied humanity from its earliest steps, through its darkest ages of science denial and religious persecution, in some of its greatest cultural accomplishments all the way to the development of modern science and quantum gravity.
But what exactly is “the One”? What is recorded on the cosmic film roll? If it stores everything that could possibly happen, are these possibilities logical possibilities, meaning that the properties of “the One” turn out to be self-evident, or a more constrained set of physical possibilities? And what is the film roll or the projector itself? Is “the One” material? Is it spirit or information? Is it math? None of the above? There is no easy resolution yet. All of these positions have their advocates.
We are in an awkward situation. On one hand, as quantum computing pioneer David Deutsch has urgently appealed, “We’ve got to understand this thing… because otherwise in every fundamental branch of physics it’s as if we were planning an expedition to the moon while still thinking that the earth is flat.”1 Yet, on the other hand, as the philosopher Galen Strawson lamented in the New York Times, physics “tells us a great many facts about the mathematically describable structure of physical reality, facts that it expresses with numbers and equations… but it doesn’t tell us anything at all about the intrinsic nature of the stuff that fleshes out this structure.”2 “Physics is silent… on this question,” Strawson determines, and keeps pressing, “What is the fundamental stuff of physical reality, the stuff that is structured in the way physics reveals?”3 At least for the moment, Strawson is perfectly right in his complaint.
One vocal champion of the hypothesis that the universe is made of information is Seth Lloyd, a pioneer of quantum information science and professor of mechanical engineering and physics at the Massachusetts Institute of Technology. Lloyd believes that the universe is properly characterized as a quantum computer:4 “The universe is made of bits,” Lloyd writes in his book Programming the Universe.5 “Effectively everything is computing,” Lloyd explains in an interview.6 “In an actual computer we are accustomed socially to refer to hardware and software. But… this distinction is actually not as precise as what one likes to think… The particle is the barcode.”7
Lloyd’s way of thinking about the universe is grounded in a fundamental concept in the theory of computation. In 1936, the English mathematician Alan Turing invented the “Turing Machine,” an abstract mathematical model for a universal computer. Turing had a tragic life story. As a code breaker in World War II, Turing contributed crucially to the cracking of intercepted encrypted communications between the Nazis and their co-combatants and thus to the Allies’ victory. Nevertheless, when, after the war, Turing’s homosexuality became known, it was prosecuted as a crime, and he was sentenced to a forced hormonal treatment that eventually drove him to commit suicide. Not until 2013, with the support of Stephen Hawking, did Queen Elizabeth II grant him a posthumous pardon.
Among his many other accomplishments, Turing contributed mightily to the foundations of information science. Just like modern computers, the Turing Machine provided an all-purpose device whose actual action was determined by the software it was running. A few years later, the German engineer Konrad Zuse—who, supported by funding from the Nazi military, had built the first programmable computer in 1941—went one step further by suggesting that the universe could be understood as “Computing Space.” Later Carl Friedrich von Weizsäcker in Germany and John Wheeler in the United States developed this idea further, culminating in Wheeler’s slogan “It from Bit,” advocating that “every particle, every field or force, even the spacetime continuum itself—derives its function, its meaning, its very existence entirely—even if in some contexts indirectly—from the apparatus-elicited answers to yes or no questions, binary choices, bits.”8
In fact, computer scientists use strings of zeroes and ones, so-called bits, to encode vast amounts of information that can simulate or characterize complex behavior. In quantum computing, the classical bit gets replaced by the “Q-Bit,” which can be thought of as the information stored in a particle’s spin pointing up or down. So far this concept of information still describes how matter is organized but not the identity of matter itself. Yet, in some cases, the Q-Bit description of a particle’s spin can be generalized to determine the particle’s self. As mentioned already in Chapter 6, Werner Heisenberg had pointed out in 1932 that, for example, the protons and neutrons constituting the atomic nucleus behave so similarly that they can be understood as two states of a single particle—a perfect analogy to a quantum spin or Q-Bit. Curiously, in this way the apparent material difference of proton and neutron is reduced to the information stored in the Q-Bit. An analogous argument can be made for the difference between electrons and neutrinos.9 In the hypothetical grand unified theories developed by particle theorists since the 1970s to eventually unify all matter in the universe, this notion is taken to the extreme in that all known particles are understood now as different states of a single particle (or quantum field). In this case, the question about what exactly the hardware of the universe is becomes increasingly irrelevant, since what characterizes how the universe appears to us is determined by the information stored in this hardware rather than by the hardware itself. Just as the same USB stick can store different movies or songs and thus entirely different experiences and emotional evocations, or as computers of different makes can play the same movie and evoke the same experiences or emotional evocations irrespective of how they are built internally, the underlying hardware becomes meaningless, and what has meaning is how this hardware is organized, what information it actually stores and processes.
This is as close as it gets to Plato’s book Timaeus, in which the philosopher develops the conception that everything we experience as outside reality is produced by informational patterns imprinted in the “midwife of being.” As Lloyd emphasizes, “A quantum computer can simulate any local quantum system,” meaning that indeed “the standard model and (presumably)… quantum gravity”—in other words, everything—“can be directly reproduced by a quantum… automaton.”
According to Lloyd, such a picture can explain why the universe appears so complex while the actual laws of physics are apparently quite simple: “The reason is that many complex, ordered structures can be produced from short computer programs, albeit after lengthy calculations,” Lloyd writes.10 “In the beginning was the bit,” Lloyd explains and goes on to flesh his idea out as follows: “As soon as the universe began, it began computing. At first, the patterns it produced were simple, comprising elementary particles and establishing the fundamental laws of physics. In time, as it processed more and more information, the universe spun out ever more intricate and complex patterns.”11 Examples include, according to Lloyd, “galaxies, stars, and planets. Life, language, human beings, society, culture—all owe their existence to the intrinsic ability of matter and energy to process information.”12 A famous example for a simple computer program giving rise to a plethora of complex structures is the Mandelbrot set, where new, aesthetic patterns are unveiled over and over again upon zooming into the fractal picture produced as an output. In a paper written in 1996, Max Tegmark took this idea to the extreme, suggesting that the universe does “in fact contain almost no information.”13 As Tegmark argues, “Decoherence together with the standard chaotic behavior of certain non-linear systems will make the universe appear extremely complex to any self-aware subsets that happen to inhabit it now, even if it was in a quite simple state shortly after the big bang.”14 In fact, if we return once more to Plato’s cave, the shadows of things aren’t the consequence of anything being added to the light of the sun but instead of light being screened from hitting the cave’s wall, just like art carved into wood takes wood away instead of adding anything. If this is more than just a loose analogy, maybe “the One” is close to an empty canvas or a projector with no movie mounted.
But do these arguments really imply that “information comes first”? After all, information acquires its meaning only if we possess the proper software and operating system to extract this information from the hardware and process it. If we can play a recent blockbuster movie or a Leonard Cohen song from a memory stick, this doesn’t make the memory stick “information.” The stick is still a piece of metal, and its configuration is given by the exact states of the particles it is made of. With the help of proper software and another hardware device to play it, we can interpret this configuration as the information (i.e., the movie or song) we want to enjoy. Likewise, if we want to see how a neutrino or electron behaves, we need other quantum fields, such as force carrier or “gauge” quantum fields, to mediate their effects. Information has to be physically incorporated to become effective. Nobody—to give a drastic example—has ever been beaten to death with a Beethoven symphony, unless maybe it was scribbled on a piece of rock.
Arguably the most radical version of the idea that the universe is nothing but information has been proposed by Max Tegmark. “I will push this idea to its extreme and argue that our universe is mathematics in a well-defined sense,” Tegmark wrote.15 As he explains, “Whereas the customary terminology in physics textbooks is that the external reality is described by mathematics,” he goes (at least) one step further and states that “it is mathematics.”16 Tegmark’s argument is similar to Lloyd’s, which is based on Turing’s universal computer: “If two structures are [having a one-to-one correspondence], then there is no meaningful sense in which they are not one and the same,” Tegmark writes.17 Anything else, such as matter, mind, space, and time, is dismissed by him as “baggage.” “One could argue that our universe is somehow made of stuff perfectly described by a mathematical structure, but which also has other properties that are not described by it, and cannot be described in an abstract baggage-free way,” Tegmark admits, but he insists that “those additional bells and whistles that make the universe nonmathematical by definition have no observable effects whatsoever.” But is this correct? Are these “bells and whistles” that make the universe nonmathematical really unobservable? One could argue that the physical realization of the mathematical structure describing the universe is what makes the universe observable in the first place, raising the concern that Tegmark’s proposal confuses reality with the model describing it, making it a prime example of what philosophers call a “category mistake.”
It thus appears to be more correct to think of information not as coming first but rather as a convenient way to speak about how the underlying hardware, how “the One,” is organized. But there is yet another twist in this story: everything we know or experience about the world we know or experience only insofar as it exists or is represented in our conscious minds. For us, only that exists which we are conscious of, and consciousness arguably is processed information. So if everything exists exclusively in our minds, and if our minds are nothing but information, doesn’t this again imply that everything is information? It appears as if we are running in circles, removing ourselves more and more from our actual experiences and observations. Just as in discussing the priority of consciousness versus matter, we run into a chicken-egg problem when we try to find out what is prior: matter or information.
But maybe this is the wrong question to ask. Maybe we shouldn’t wonder whether the projector reality is either information, like that stored in an on-screen book or on a memory stick or hard disk, or matter, like an on-screen brick, chair, or house. Maybe we should do the converse: understand the classical, on-screen reality as information about the quantum realm; see the movie plot experienced on-screen as information about what exists in the projector room rather than understanding the film roll as information about the story that unfolds on the screen.
The chicken-egg problem of matter and information: What is more fundamental, matter or information? Matter is represented in conscious experience that arguably results from information processing in the brain. Information, however, is physically realized in matter.
When I discussed these problems with H. Dieter Zeh, he wrote to me, “In this context I consider [‘real’] only as ‘physically real’… Therefore for me also e.g. the constitutional law isn’t real, but only its ‘realization’ on paper or within a material brain.”18 When asked whether he would describe the quantum mechanical wave function as “material,” though, he said no: “While I wouldn’t call the wave function ‘material,’ I would call it ‘real’… This is something entirely different as ‘only math’ or ‘only information.’”19
As Zeh put it in “The Wave Function: It or Bit,” his invited chapter for a book to celebrate John Wheeler’s ninetieth birthday, “If ‘it’ (reality) is understood in the operationalist sense, while the wave function is regarded as ‘bit’ (incomplete knowledge about the outcome of potential operations), then one or the other kind of ‘it’ may indeed emerge ‘from bit.’” Zeh admitted that for practical purposes, such a mind-set is useful: “I expect that this will remain the pragmatic language for physicists to describe their experiments for some time to come.” Yet he continued to contrast this pragmatic attitude with an approach asking for the foundations of reality: “However, if ‘it’ is required to be described in terms of not necessarily operationally accessible but instead universally valid concepts, then the wave function remains as the only available candidate for ‘it’… However you turn it: In the Beginning Was the Wave Function.”20
Following Zeh, we have eventually arrived at an understanding of quantum mechanics that is diametrically opposed to Niels Bohr’s view. Instead of conceiving the wave function as a tool providing information about the potential behavior of the classical objects in everyday life, this new view suggests nothing less than the contrary: classical objects, space, time, and matter have to be conceived as information about the underlying quantum reality. The behavior of classical objects allows us to constrain the space of possibilities that characterizes this fundamental reality, and the more we learn about quantum cosmology, the better we will understand what “the One” really is. Once more we can stress the parallels with Plato, who envisaged the way to truth as a strenuous ascent out of the cave, or with the metaphor of the veiled Isis, whose veil provides us with limited information about what hides beneath it.
From a monistic perspective, both matter and information experienced in the daily-life, on-screen reality reveal information about the hidden reality, the fundamental “One.”
Particles and the Universe
We started this book by realizing that if “all is One,” it doesn’t make sense anymore to think about the universe as composed of particles. Rather, the opposite is true: any conglomeration of particles is nothing but a specific perspective on the all-encompassing One. Such a view does nothing less than turn the quest for the foundations of physics upside down. Taking this book’s argument to its logical conclusion, physics can only move forward by building on quantum cosmology instead of particles or strings. At some point—and the persisting fine-tuning problems that researchers encounter may indicate that this point has been reached—probing continually smaller distances and higher energies won’t help us get closer to the foundations of physics.
This provokes the obvious question about what role particle physics can play in the future. Does it still make sense to invest billions of dollars in future particle accelerators, or is this money better invested in other branches of science? It should be stressed that particle physics will remain important. Unless it is completely understood how and why particle physics fails to uncover the essence of the universe and provide natural explanations for dark energy and the Higgs mass, the investigation of what exactly goes wrong and where the logic of “smaller is more fundamental” reaches its limits will remain an indispensable contribution to understanding “what’s really going on below.” Yet particle physicists will have to accept a new, more modest role in this endeavor; the field won’t be able to claim to be the silver bullet to understand the cosmos anymore. Instead, particle physics will concentrate increasingly on why and where the naive reductionism of the particle approach fails.
In this new role, particle physics will remain an important pillar for foundational physics, but it will have to be supplemented by intensified efforts in research on quantum information and quantum foundations as well as cosmology. Various subdisciplines in physics, so far conceived of as essentially unrelated, will have to close ranks to unveil the foundation of nature. Which concrete experiment may play a key role in the various stages of this endeavor will have to be assessed, based on the concrete open questions in need of investigation and an honest cost-benefit analysis.
