Seth Lloyd presents a computational cosmology perspective, in which the universe is understood as a quantum computer. He argues that the universe is a sophisticated device that processes information according to the laws of quantum mechanics. This view can efficiently explain the complexity and order of the universe and offers a new paradigm.
‘In the beginning there were bits.’ This statement may be puzzling to someone who hasn’t read the book. Most people who have not read this book will be surprised to hear this statement. Modern physicists are interested in two main questions. The first is what the universe is made of, and the second is how it works. Seth Lloyd, the author of this book, seeks to explain the nature of the universe through the results of decades of research in the cutting-edge field of quantum information science. He argues that we need to understand the universe as a quantum computer in order to interpret all its phenomena. Let’s take a look at Seth Lloyd’s arguments and then formulate my own opinion.
The laws of quantum mechanics are at the center of the principles that make the cosmic computer work. The universe is a sophisticated information-processing device that performs calculations on the information contained within it according to the laws of quantum mechanics, and scientists have been studying and experimenting with the possibility of implementing such a device. This is what a “quantum computer” is: the very idea of a quantum computer is modeled after the universe. To explain the phenomenon of quantum superposition, which is the basis of the laws of quantum mechanics, the author cites Jorge Borges’ novel “The Garden of Endlessly Diverging Paths”. In this strange garden, all possible outcomes occur, and each outcome is the starting point for the next branch. It’s a concept similar to the butterfly effect, where small changes can lead to different outcomes if the paired particles are quantum superposed, meaning that no matter how far apart they are, changes in one will affect the other. This is called quantum superposition or entanglement and is the most important theory in modern quantum mechanics. Modern physics values symmetry, so all particles exist in pairs. In these pairs, no matter how far apart they are, any change in one particle affects the other. For example, imagine two particles, one of which spins counterclockwise and the other clockwise. According to quantum mechanics, we don’t know which way particles 1 and 2 are spinning before we observe them, only that they are spinning opposite each other. They are always related, such that if we observe particle 1 spinning counterclockwise, particle 2 is determined to be spinning clockwise, and if we observe particle 1 spinning clockwise, particle 2 is determined to be spinning counterclockwise.
Because the laws of quantum mechanics are different from the laws of classical mechanics, quantum computers governed by the laws of quantum mechanics are also significantly different from the classical computers we are familiar with. As is well known, the basic unit of information processing is the bit, which contains either 0 or 1 information in a single bit. However, if we recall the concept of superposition in quantum mechanics, bits in the quantum world, or quantum bits, are two events that can never happen simultaneously: 0 and 1. Quantum computers are capable of this superposition and can process information given by quantum bits, allowing them to perform extremely complex and intricate calculations at once. Quantum computers can simulate physical systems that are impossible for classical computers to simulate, which is what the authors call quantum computation.
The author believes that the “computational universe” view of the universe as a quantum computer can better explain the complexity and order of the universe. According to Boltzmann, the complexity of the universe arose from chance, but this does not explain the intriguing order and complexity of the universe, which is constantly underway. The author believes that the richness and complexity inherent in the information-processing processes of a computing universe can efficiently explain this complexity and order. In his view, even at this very moment, the universe we live in is constantly processing information, following the sophisticated laws of quantum mechanics and performing calculations on the universe itself, which is made up of quantum bits. All the wonders of nature are expressions of the universe’s quantum computational power. To explain what Boltzmann had in mind, which could not be explained by a world dominated by chance alone, the author introduces the idea of a “computing universe” and presents it as a new paradigm.
This is how Seth Lloyd wanted to explain the universe, and after reading the book several times and thinking about whether I agree with his arguments, my answer is yes. This theory, like the superstring theory, can explain the universe, but it lacks experimental evidence. But whereas superstring theory is a rather unconvincing explanation for everything, the system Seth Lloyd describes is clean and free of errors. The comparison between classical machines and quantum computers reminded me of a watch and a computer. A watch is a very classical machine, and its complexity and technical sophistication are immense. However, if something goes wrong with a watch and it runs one second slower for a long time, it’s just a watch that’s one second slower and nothing has changed. In the case of computers, however, when programming, small inputs can cause significant changes in the output, sometimes unpredictable. The author explains the multiverse and cosmology by comparing it to a computer, combining existing theories with his own, and as I watched, I thought that the lack of errors was a great advantage of this theory. Also, the explanation in connection with thermodynamics, an already established theory, was enough to convince me. ‘Information accumulates and becomes meaningful as it accumulates. Information is an accumulation.’ Information itself is a record of events that happen over time, and information becomes meaningful when it accumulates over time and does not disappear. The second law of thermodynamics, the most basic law of the universe, states that the entropy, or disorder, of the universe is always increasing. This increasing entropy also implies accumulation. The fact that a new explanatory system can be linked to an already established theory is another argument in favor of this claim.
Whereas Newton’s world was a simple machine, Seth Lloyd’s world is a gigantic information of bits and a quantum computer that processes that information. This is in addition to the intrinsic elements of quantum mechanics: the quantum superposition of multiple states and the probabilistic chance of measurement. This makes the universe behave very differently from a classical machine and allows for a richer representation of the universe as it exists. We believe that this new explanatory scheme is infallible for describing the current universe, and we believe that further development of this idea could inform the solution to scientists’ greatest challenge: a theory of everything, a unified field theory that explains all the forces and phenomena in the universe. The convenience of a unified field theory would be indescribable. If the author is right, the universe works like a quantum computer, and it is possible to establish a system that explains all phenomena and forces as information, and I think we should do more research in this direction.
