Category: Physics

Metaphors as Bridges to the Future

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David Lewis’s (I’m coming to accept this new convention with s-ending possessives!) solution to Putnam’s semantic indeterminacy is that we have a network of concepts that interrelate in a manner that is consistent under probing. As we read, we know from cognitive psychology, texts that bridge unfamiliar concepts from paragraph to paragraph help us to settle those ideas into the network, sometimes tentatively, and sometimes needing some kind of theoretical reorganization as we learn more. Then there are some concepts that have special referential magnetism and are piers for the bridges.

You can see these same kinds of bridging semantics being applied in the quest to solve some our most difficult and unresolved scientific conundrums. Quantum physics has presented strangeness from its very beginning and the various interpretations of that strangeness and efforts to reconcile the strange with our everyday logic remains incomplete. So it is not surprising that efforts to unravel the strange in quantum physics often appeal to Einstein’s descriptive approach to deciphering the strange problems of electromagnetic wave propagation that ultimately led to Special and then General Relativity.

Two recent approaches that borrow from the Einstein model are Carlo Rovelli’s Relational Quantum Mechanics and David Albert’s How to Teach Quantum Mechanics. Both are quite explicit in drawing comparisons to the relativity approach; Einstein, in merging space and time, and in realizing inertial and gravitational frames of reference were indistinguishable, introduced an explanation that defied our expectations of ordinary, Newtonian physical interactions. Time was no longer a fixed universal but became locked to observers and their relative motion, and to space itself.

Yet the two quantum approaches are decidedly different, as well. For Rovelli, there is no observer-independent state to quantum affairs.… Read the rest

Causing Incoherence to Exist

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I was continuing discussion on Richard Carrier vs. the Apologists but the format of the blog posting system made a detailed conversation difficult, so I decided to continue here. My core argument is that the premises of Kalam are incoherent. I also think some of the responses are as well.

But what do we mean by incoherent?

Richard interpreted that to mean logically impossible, but my intent was that incoherence is a property of the semantics of the words. Statements are incoherent when they don’t make sense or only make sense with a very narrow and unwarranted reading of the statement. The following argument follows a fairly standard analytic tradition analysis of examining the meaning of statements. I am currently fond of David Lewis’s school of thought on semantics, where the meaning of words exist as a combination of mild referential attachment, coherence within a network of other words, and, importantly, some words within that network achieve what is called “reference magnetism” in that they are tied to reality in significant ways and pull at the meaning of other words.

For instance, consider Premise 1 of a modern take on Kalam:

All things that begin to exist have a cause.

OK, so what does begin to exist mean? And how about cause? Let’s unpack “begin to exist,” first. We might say in our everyday world of people that, say, cars begin to exist at some point. But when is that point? For instance, is it latent in the design for the car? Is it when the body panels are attached on the assembly line? Is it when the final system is capable of car behavior? That is, when all the parts that were in fact designed are fully operational?… Read the rest

Two Points on Penrose, and One On Motivated Reasoning

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Sir Roger Penrose is, without doubt, one of the most interesting polymaths of recent history. Even where I find his ideas fantastical, they are most definitely worth reading and understanding. Sean Carroll’s Mindscape podcast interview with Penrose from early January of this year is a treat.

I’ve previously discussed the Penrose-Hameroff conjectures concerning wave function collapse and their implication of quantum operations in the micro-tubule structure of the brain. I also used the conjecture in a short story. But the core driver for Penrose’s original conjecture, namely that algorithmic processes can’t explain human consciousness, has always been a claim in search of support. Equally difficult is pushing consciousness into the sphere of quantum phenomena that tend to show random, rather than directed, behavior. Randomness doesn’t clearly relate to the “hard problem” of consciousness that is about the experience of being conscious.

But take the idea that since mathematicians can prove things that are blocked by Gödel incompleteness, our brains must be different from Turing machines or collections of them. Our brains are likely messy and not theorem proving machines per se, despite operating according to logico-causal processes. Indeed, throw in an active analog to biological evolution based on variation-and-retention of ideas and insights that might actually have a bit of pseudo-randomness associated with it, and there is no reason to doubt that we are capable of the kind of system transcendence that Penrose is looking for.

Note that this doesn’t in any way impact the other horn of Penrose-Hameroff concerning the measurement problem in quantum theory, but there is no reason to suspect that quantum collapse is necessary for consciousness. It might flow the other way, though, and Penrose has created the Penrose Institute to look experimentally for evidence about these effects.… Read the rest

Theoretical Reorganization

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Sean Carroll of Caltech takes on the philosophy of science in his paper, Beyond Falsifiability: Normal Science in a Multiverse, as part of a larger conversation on modern theoretical physics and experimental methods. Carroll breaks down the problems of Popper’s falsification criterion and arrives at a more pedestrian Bayesian formulation for how to view science. Theories arise, theories get their priors amplified or deflated, that prior support changes due to—often for Carroll—coherence reasons with other theories and considerations and, in the best case, the posterior support improves with better experimental data.

Continuing with the previous posts’ work on expanding Bayes via AIT considerations, the non-continuous changes to a group of scientific theories that arrive with new theories or data require some better model than just adjusting priors. How exactly does coherence play a part in theory formation? If we treat each theory as a binary string that encodes a Turing machine, then the best theory, inductively, is the shortest machine that accepts the data. But we know that there is no machine that can compute that shortest machine, so there needs to be an algorithm that searches through the state space to try to locate the minimal machine. Meanwhile, the data may be varying and the machine may need to incorporate other machines that help improve the coverage of the original machine or are driven by other factors, as Carroll points out:

We use our taste, lessons from experience, and what we know about the rest of physics to help guide us in hopefully productive directions.

The search algorithm is clearly not just brute force in examining every micro variation in the consequences of changing bits in the machine. Instead, large reusable blocks of subroutines get reparameterized or reused with variation.… Read the rest

Indifference and the Cosmos

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I am a political independent, though that does not mean that I vote willy-nilly. I have, in fact, been reliably center left for most of my adult life, save one youthfully rebellious moment when I voted Libertarian, more as a statement than a commitment to the principles of libertarianism per se. I regret that vote now, given additional exposure to the party and the kinds of people it attracts. To me, the extremes of the American political system build around radical positions, and the increasingly noxious conspiracy theories and unhinged rhetoric is nothing like the cautious, problem-solving utopia that might make me politically happy, or at least wince less.

Some might claim I am indifferent. I would not argue with that. In the face of revolution, I would require a likely impossible proof of a better outcome before committing. How can we possibly see into such a permeable and contingent future, or weigh the goods and harms in the face of the unknown? This idea of indifference, as a tempering of our epistemic insights, serves as a basis for an essential idea in probabilistic reasoning where it even has the name, the principle of indifference, or, variously, and in contradistinction with Leibniz’s principle of sufficient reason, the principle of insufficient reason.

So how does indifference work in probabilistic reasoning? Consider a Bayesian formulation: we inductively guess based on a combination of a priori probabilities combined with a posteriori evidences. What is the likelihood of the next word in an English sentence being “is”? Indifference suggests that we treat each word as likely as any other, but we know straight away that “is” occurs much more often than “Manichaeistic” in English texts because we can count words.… Read the rest

Gravity and the Dark Star

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I began at 5 AM from the Broomfield Aloft hotel, strategically situated in a sterile “new urban” office park cum apartment complex along the connecting freeway between Denver and Boulder. The whole weekend was fucked in a way: colleges across Colorado were moving in for a Monday start, half of Texas was here already, and most of Colorado planned to head north to the zone of totality. I split off I-25 around Loveland and had success using US 85 northbound through Cheyenne. Continuing up 85 was the original plan, but that fell apart when 85 came to a crawl in the vast prairie lands of Wyoming. I dodged south and east, then, (dodging will be a continuing theme) and entered Nebraska’s panhandle with middling traffic.

I achieved totality on schedule north of Scottsbluff. And it was spectacular. A few fellow adventurers were hanging out along the outflow lane of an RV dump at a state recreation area. One guy flew his drone around a bit. Maybe he wanted B roll for other purposes. I got out fast, but not fast enough, and dodged my way through lane closures designed to provide access from feeder roads. The Nebraska troopers were great, I should add, always willing to wave to us science and spectacle immigrants. Meanwhile, SiriusXM spewed various Sibelius pieces that had “sun” in their name, while the Grateful Dead channel gave us a half dozen versions of Dark Star, the quintessential jam song for the band that dates to the early, psychedelic era of the band.

Was it worth it? I think so, though one failed dodge that left me in a ten mile bumper-to-bumper crawl in rural Nebraska with a full bladder tested my faith in the stellar predictability of gravity.… Read the rest

Quantum Field Is-Oughts

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teleologySean Carroll’s Oxford lecture on Poetic Naturalism is worth watching (below). In many ways it just reiterates several common themes. First, it reinforces the is-ought barrier between values and observations about the natural world. It does so with particular depth, though, by identifying how coarse-grained theories at different levels of explanation can be equally compatible with quantum field theory. Second, and related, he shows how entropy is an emergent property of atomic theory and the interactions of quantum fields (that we think of as particles much of the time) and, importantly, that we can project the same notion of boundary conditions that result in entropy into the future resulting in a kind of effective teleology. That is, there can be some boundary conditions for the evolution of large-scale particle systems that form into configurations that we can label purposeful or purposeful-like. I still like the term “teleonomy” to describe this alternative notion, but the language largely doesn’t matter except as an educational and distinguishing tool against the semantic embeddings of old scholastic monks.

Finally, the poetry aspect resolves in value theories of the world. Many are compatible with descriptive theories, and our resolution of them is through opinion, reason, communications, and, yes, violence and war. There is no monopoly of policy theories, religious claims, or idealizations that hold sway. Instead we have interests and collective movements, and the above, all working together to define our moral frontiers.

 … Read the rest

On Woo-Woo and Schrödinger’s Cat

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schrodingers-cat-walks-into-a-bar-memeMichael Shermer and Sam Harris got together with an audience at Caltech to beat up on Deepak Chopra and a “storyteller” named Jean Houston in The Future of God debate hosted by ABC News. And Deepak got uncharacteristically angry back behind his crystal-embellished eyewear, especially at Shermer’s assertion that Deepak is just talking “woo-woo.”

But is there any basis for the woo-woo that Deepak is weaving? As it turns out, he is building on some fairly impressive work by Stuart Hameroff, MD, of University of Arizona and Sir Roger Penrose of Oxford University. Under development for more than 25 years, this work has most recently been summed up in their 2014 paper, “Consciousness in the universe: A review of the ‘Orch OR’ theory” available for free (but not the commentaries, alas). Deepak was even invited to comment on the paper in Physics of Life Reviews, though the content of his commentary was challenged as being somewhat orthogonal or contradictory to the main argument.

To start somewhere near the beginning, Penrose became obsessed with the limits of computation in the late 80s. The Halting Problem sums up his concerns about the idea that human minds can possibly be isomorphic with computational devices. There seems to be something that allows for breaking free of the limits of “mere” Turing Complete computation to Penrose. Whatever that something is, it should be physical and reside within the structure of the brain itself. Hameroff and Penrose would also like that something to explain consciousness and all of its confusing manifestations, for surely consciousness is part of that brain operation.

Now, to get at some necessary and sufficient sorts of explanations for this new model requires looking at Hameroff’s medical speciality: anesthesiology.… Read the rest

Entanglement and Information

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shannons-formula-smallResearch can flow into interesting little eddies that cohere into larger circulations that become transformative phase shifts. That happened to me this morning between a morning drive in the Northern California hills and departing for lunch at one of our favorite restaurants in Danville.

The topic I’ve been working on since my retirement is whether there are preferential representations for optimal automated inference methods. We have this grab-bag of machine learning techniques that use differing data structures but that all implement some variation on fitting functions to data exemplars; at the most general they all look like some kind of gradient descent on an error surface. Getting the right mix of parameters, nodes, etc. falls to some kind of statistical regularization or bottlenecking for the algorithms. Or maybe you perform a grid search in the hyperparameter space, narrowing down the right mix. Or you can throw up your hands and try to evolve your way to a solution, suspecting that there may be local optima that are distracting the algorithms from global success.

Yet, algorithmic information theory (AIT) gives us, via Solomonoff, a framework for balancing parameterization of an inference algorithm against the error rate on the training set. But, first, it’s all uncomputable and, second, the AIT framework just uses strings of binary as the coded Turing machines, so I would have to flip 2^N bits and test each representation to get anywhere with the theory. Yet, I and many others have had incremental success at using variations on this framework, whether via Minimum Description Length (MDL) principles, it’s first cousin Minimum Message Length (MML), and other statistical regularization approaches that are somewhat proxies for these techniques.… Read the rest

A, B, C time!

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time-flows-awayThis might get technical, despite the vaguely Sesame Street quality to the title. You see, philosophers have long worried over time and causality, and rightly so, going back to the Greeks like Heraclitus and Parmenides, as well as their documenters many years later. Is time a series of events one after another or is that a perceptual mistake? For if everything comes from some cascade of events that precede it, it is illogical to presume that something might emerge from nothing (Parmenides). And, contra, perhaps all things are in a state of permanent change and all such perceptions are confused (Heraclitus). The latter has some opaque formulations in the appreciation of the Einsteinian relativistic form of combining space and time together while still preserving the symmetry of time in the basic equations, allowing for the rolling forward and backward of the space-time picture without much in the way of consequences.

So Lee Smolin’s re-injection of time as a real phenomena in Time Reborn takes us from A and B theories of time to something slightly new, which might be called a C theory. This theory builds on Smolin’s previous work where he proposed an evolutionary model of cosmology to explain how the precarious constants of our observed universe might have come into being. In Smolin’s super-cosmology, many universes come to be and not be at an alarming rate. Indeed, perhaps in every little black hole is another one. But many of these universes are not very viable because they lack the physical constants needed to last a long time and for entities like us to evolve to try to comprehend them. This does away with any mysteries about the Anthropic Principle: we are just survivors.… Read the rest