I’ve been a little quiet here lately, partly because I’ve been busy and partly because I’ve been thinking through some ideas about science and religion during Easter seaon. Hopefully as my ideas gel I’ll find time to post them so that y’all can shoot at them and help me vet them. (I also have quite the backlog of articles that I’ve wanted to point to and I’m planning on getting them posted over the next couple of weeks.)
I saw news that an important new test of the idea of Quantum Darwinism was announced the middle of last week, and I’ve been thinking about that and the larger concepts all week since. Quantum Darwinism is a relatively recent attempt to make sense of how nature and phenomenon exist in both a quantum regime and a classical regime. Actually, more specifically, it’s an attempt to explain how the observations of classical physics can arise from the non-intuitive world of quantum physics.
The idea in a nutshell is that quantum states that are suited to propagate at classical length scales are naturally selected over the states that are not. It’s called Quantum Darwinism because this idea of natural selection obviously evokes the simple yet profound similar insight that Charles Darwin had when observing biological systems.
The idea was first proposed by Wojciech Zurek, a physicist at Los Alamos back in 2003. A simple summary can be found here.
How does it work? Zurek’s way into this problem is to think about the role of the environment in quantum mechanics. For other quantum physicists, the environment has never been anything more than a nuisance. Consider a quantum object in isolation and the quantum information it contains can survive forever. But place it in the real world and this quantum information leaks into the environment, destroying the system under study.
Zurek takes different view. He thinks of the environment as an information channel and the properties of this channel are the key to understanding quantum darwinism.
All macroscopic measuring machines get their information through this channel. For example, at this very moment you are intercepting a fraction of the photons emitted by a screen. But we can never observe all of the environment, only a small fraction of it which reveal systems of interest.
This is the essence of quantum darwinism, says Zurek. Only quantum states that can be transmitted through the environment in the right kind of way and with multiple copies, can be observed on the macroscopic scale. That rules out various kinds of quantum information. What’s left are what Zurek calls “pointer states”. These are what we observe classically.
So the classical view of the universe is determined by the states that survive transmission through the environmental information channel. Hence the darwinism: it is only possible to observe the states that are fit enough to survive this process of transmission.
It’s a sort of self-evident idea once it occurs to you, but it has the gift of giving a sort of intuitive basis to the idea of de-coherence (an idea I’ve always struggled to get my mind wrapped properly around).
Of course all lovely models need to be tested to see if they’re useful for making predictions. (String theory is one of those lovely models that has yet to actually make a prediction that can be tested.) The news from last week is that researchers have managed to find a mechanism to test Quantum Darwinism to a stronger physical footing:
“[R]ecently, a team of physicists and engineers from Arizona State University and the Naval Research Laboratory in Washington, D.C., has performed experiments using scanning gate microscopy to image scar structures in an open quantum dot. Their results have revealed the existence of periodic scar offspring states that evolve and eventually contribute to a robust state, much in the way that the derivation of pointer states is predicted by quantum Darwinism.
The ‘scars,’ as the researchers explained, are actually scarring on the quantum wave functions, which cause the wave functions’ amplitudes to be highly concentrated along classical trajectories. Scars are traditionally thought to be unstable, where any small perturbation could break up the connection to the classical trajectory. However, when scar states replicate and evolve through quantum Darwinism, becoming a family of mother-daughter states, they can become coherent and eventually stabilize into multiple pointer states.
[…]‘The magnetic periodicity, which we used to get the experimental data results, is the ‘smoking gun’ for quantum Darwinism,’ coauthor David Ferry of Arizona State University told PhysOrg.com.”
So, assuming this published result survives peer-review and other tests, we may actually have something exciting here.
What I personally find so interesting is this idea that it the states which propagate to the classical realm are the ones that are suited to do so. The ones that don’t, don’t.
Science (at least since the writing of Popper) is based on the idea that claims made by ideas are adjudicated in the lab. What the lab test supports is what is accepted. In other words the lab bench becomes the referee between competing theoretical world-views of the Universe. Once the lab bench has spoken, we know which branching path to choose to be able to push the boundary of knowledge further out.
In the Church, we have a similar situation with many different bodies making competing claims about God and about the nature of Truth. How can we decide which one is worth investing in? Which one is right?
I’ve wondered from time to time if we might think about this question the same way as we do Quantum Darwinism. The Church with the correct understanding of reality is the one that survives and is sustainable. The one that doesn’t is naturally selected out.
The most obvious objection to the idea is that it would seem to imply that the secular world is then seen as the referee of the Bible. But that’s true anyhow isn’t it? We believe the biblical witness to Jesus to be both true and timeless. If information comes along that (once verified as being accurate) seems to contradict the biblical teaching, we re-adjust our interpretation of the teaching. (It’s not so much that we re-adjust our interpretation, but that we have to find a way to incorporate the new information into a new expanded understanding of what the Bible teaches.)
The alternative to doing this is to deny the new verified information. (Sort of like the Creation Museum does in its almost frantic attempt to hammer scientific information into a form that will not cause us to expand our understanding of the creation accounts.) In a country which is seeing the rise of more and more “Anti-Science” even to the point where it’s nearly a political party, this is an attractive alternative to many.
If God is really present in reality, and the Church’s life is really animated by the presence of the Holy Spirit, then this idea that the Churches which propagate in time are the ones with the correct understanding isn’t terribly surprising. The closer you hew to God’s revealed truth, the more ancient and more future proof you become.
I guess in a nutshell this isn’t really anything new. It’s just a restatement of the biblical teaching of Rabbi Gamaliel in Acts. If the Church is of God, it will survive. If it is not, it will naturally whither.
If this is true, I hope it gives us all pause.