Note: Yes, this is the Literary Salon, but imagine, if you will, a pit stop in quantum mechanics, as we seek to understand the workings of the universe. Next week, we return to mastering fiction and discuss a theory of character creation.
Bridging Quantum Weirdness and the World We Know
We learn early that entropy will tear the universe apart, leaving nothing but microscopic bits scattered across space. What they didn’t tell us is that the interaction of two forms of entropy creates the universe as we see it and allows us to see it at all.
You and I witness the arrow of time because of entropy. We think of entropy as the process of things breaking down, but it’s an organized system (a state of low entropy) moving into a homogeneous, universal mixture (a state of high entropy). States of low entropy enable energy to accomplish a myriad of strange and wonderful tasks. In a state of high entropy, energy can’t accomplish anything. As for the arrow of time, low entropy states have many possibilities for moving into a high entropy state but little to no possibility of moving into a lower entropy state. This is why everything ages instead of getting younger, and because this arrow of time is about possibilities and probabilities, that suggested a wrong-headed hypothesis: time is the entropy wavefunction.
It’s not.
A discrete number of possibilities is not a wavefunction. In our macroscopic world, when we talk about a system’s possible configurations, there are direct probabilities. We can determine the probable outcomes due to entropy simply adding together all the statistical data, a very classical application of mathematics. A wavefunction isn’t about that.
Probabilities in a quantum wavefunction can be positive and negative, and they interfere with each other. These are called probability amplitudes, and they can cancel each other out or build upon one another, and the mathematics captures this with complex numbers.
Thanks to my bad hypothesis, I understand wavefunctions better, but it doesn’t stop there. The interaction between Quantum Entropy and Classical Entropy actually creates our reality.
Quantum actions are reversible. They don’t have an arrow of time. This isn’t to say that quantum microstates don’t have their own form of entropy, but that’s different. The evolution of a quantum system shifts from local, readable variables into something highly non-local through entanglements across the entire system. We saw that when discussing the Entropic Gravity hypothesis.
Macrocosmic entropy interacts with quantum entropy because a quantum system in a high-entropy environment is more likely to come in contact with that environment and trigger decoherence. Entanglement spreads out and becomes thin. This decoherence has triggered the Von Neumann entropy of the quantum subsystem, which trends toward a state of highest entanglement.
The end result of this conflict is described by the theory of Quantum Darwinism. In our current universe, which still has fairly low entropy, that process selects only the sturdiest quantum states to survive, and in turn, these produce the classical universe as we know it.
Before, we said that entanglement spreads and thins, and this is part of a second aspect of Quantum Darwinism. It doesn’t just choose the fittest quantum states, it broadcasts the information across the environment. That way, when light bounces off a dog jumping into a lake, multiple witnesses viewing that single macroscopic event will see one single reality from their different perspectives.
Quantum states don’t have an arrow of time, but their fittest attributes (a single given location, for example) are chosen by their interaction with a macroscopic environment governed by the arrow of time. This takes the microscopic world from a probabilistic and unknown state into the stable, concrete reality we observe around us, and that very observation is made possible by the same decoherence.
— Thaddeus Thomas
P.S. All corrections welcome.
Von Neumann Entropy was formulated by John von Neumann in 1927 and measures the degree of quantum entanglement and information loss within a quantum subsystem. Meanwhile, Classical Entropy is rooted in Ludwig Boltzmann and J. Willard Gibbs’s work in the late 19th-century. The Arrow of Time was formalized by Arthur Eddington in 1927. The Entropic Gravity Hypothesis was proposed by Erik Verlinde in 2010, and Quantum Darwinism was pioneered by Wojciech Zurek in 2003.
My question is: Are you're talking about a Quantum "universe", that encapsulates "all there is" and that means us? Are we inside or outside that universe? By universe, do you mean the galaxies, planets, Earth, biological life, etc? Or do you mean a theoretical universe (theory meaning nothing but guesswork)? Be cause "science" has been known to be mucho wrong (and bigly) about many things. For example: political campaign polls, wargaming, models of "sustainable" communities (a joke if there ever was one), weather forecasters, vaccine pushers ---I don't mean to say mathematical/statistical data are always wrong, we wouldn't be able to fly airplanes if it weren't for the understanding of the realities of gravity so we can overcome them, I'm just saying that predictability in a multi-variate universe (i.e. one with people in it) don't always reliably conform to expectation.
If you're using quantum physics to understand atoms and molecules and words and actions and reactions, etc. and how they interact to create A REALITY, then it's interesting food for thought, but quantum theory's usefulness in abstract mechanics is far different than it's usefulness in micro personal inter and intra interactions that are included in the universe. Put another way, if we rack the billiard balls into a triangle, they are coherent, ordered, and contained. Hit that "universe" with a cue stick, and you'll get high-level entropy (chaos). Quantum theories can explain/diagram the possibilities of the movement of the billiard balls, but it cannot reliably and replicably predict the number & color the ball will be that go in the first pocket ----unless all the balls are the same color. And we know that biological entities are not "one color fits all."
Also. if you're saying that time is measured, or can be measured by entropy ...prove it. Perhaps we are moving from chaos/uncoherence to order instead of order/coherence to chaos.