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In Evolved, humanity believes in an open future, a Neils Bohr reality (explained below) and one in which humanity has control over its choices (free will) and real chance exists. The mechanism I use in the book to explain the mechanism behind the measurement problem is cosmological in nature to allow for this metaphysical existence.
My protagonist, however, comes to believe humanity exists in a deterministic world, a David Bohm world (explained below). Part of his challenge is to overcome the deterministic nature of the physical world to save humanity’s apparently preset course of destruction. The mechanism to allow for this level of control also comes from a cosmological theory. With that, a little explanation of quantum mechanics is in order.
From a quantum perspective there are two ways of looking at our reality, and it involves the uncertainty associated with the probabilistic nature of quantum mechanics. The fundamental question about the probabilities found at the quantum level is whether they simply reflect ignorance or an indeterminate reality.
Niels Bohr is one of the founding fathers of the Copenhagen interpretation of quantum probabilities. This interpretation of the probabilistic nature of quantum mechanics is that we understand quantum wave lengths completely, but they are not deterministic. Most scientists intuitively favor this interpretation because it depicts a world of becoming, allowing for an open future, or indeterminate reality. In other words, chance is allowed for within this interpretation, which is seemingly supported by observation and mathematical constructs like chaos theory.
Yet, the Copenhagen interpretation leaves some puzzles. Foremost is the measurement problem. The theory enables extremely accurate predictions of relative probabilities at the quantum level based on deterministic wave functions calculations, but we do not understand the actual process that provides a seemingly indeterminate definitive answer on each occasion of measurement. In other words, what is the mechanism that allows for this indeterminate reality?
David Albert takes a stab at this mechanism in his book Time and Chance. Dr. Albert lays out the challenge of finding the mechanism within the Copenhagen interpretation.
The idea … is to stick with the standard way of thinking about what it means to be in a superposition, and to stick with the idea that a quantum-mechanical wave function amounts, all by itself, to a complete description of a physical system, and to account for the emergence of determinate outcomes of experiments … by means of explicit violations of the deterministic differential equations of motion, and to try to develop some precise idea of the circumstances under which those violations occur. – David Z. Albert
Dr. Albert offers one fully worked out scientific solution, which involves the GRW theory. Within this theory the wave function of a single particle almost always evolves according to linear deterministic equations of motion, except for a probability within the wave function itself for a random localization of the particle to occur. Furthermore, the effects of these “jumps” will convert superpositions of macroscopically different states in a way consistent with standard-mechanical probabilities. This mechanism allows for real dynamical chance to enter into scientific discussion and our observable reality.
David Bohm, on the other hand, produced a complete quantum theory arguing the probabilities reflect our ignorance about the complete nature of the quantum mechanical wave function. Bohm argued wave functions act like force fields, guiding the particle along a particular course. In this sense our spatial reality is fully deterministic since the wave function is deterministic. Or, in other words, the future movement of every particle can be calculated into the future if we had a complete understanding of the wave function. In this theory, chance does not exist.
Another set of theories fall into modal interpretations, which differentiate between dynamical state (determines what may be the case) and the value state (represents what is actually occurring). Since the dynamical state always evolves according to the Schrodinger equation, the evolution of our reality is entirely deterministic within these modal interpretations. Only the probabilities associated with the value state are real dynamical chances.
Quantum decoherence was developed by David Bohm. The theory does not explain a mechanism for the wave function collapse, but instead a mechanism for the appearance of the collapse. The appearance is due to “leaking” of quantum information into the environment so that the superposition of the wavelength exists, but beyond our ability to measure it. Decoherence became fundamental to Hugh Everett’s many-world interpretation and has been incorporated into various theories. Since decoherence does not provide an actual mechanism, it cannot offer an opening for chance to enter into our reality.
So with that it should be obvious it remains an open question as to what the probabilities of quantum mechanics mean. We naturally prefer to think of ourselves in control, with free will. It is decidedly unwelcome to consider the possibility that we live in a deterministic reality. But that, to me, is a fun avenue to explore since it will make the reader uncomfortable and force more consideration about ourselves.
One last note. I am by no means an expert on quantum physics or philosophy. So please leave a comment if you believe I am wrong on a theory, or misrepresented an argument.
Evolved 