#24. The Pictures in Your Head [neuroscience]

NE

Red, theory; black, fact.

My post on the thalamus suggests that in thinking about the brain, we should maintain a sharp distinction between temporal information (signals most usefully plotted against time) and spatial information (signals most usefully plotted against space). Remember that the theory of General Relativity, which posits a unified space-time, applies only to energy and distance scales far from the quotidian.

In the thalamus post, I theorized about how the brain could tremendously data-compress temporal information using the Laplace transform, by which a continuous time function, classically containing an infinite number of points, can be re-represented as a mere handful of summarizing points called poles and zeroes, scattered on a two-dimensional plot called the complex frequency plane. Infinity down to a handful. Pretty good data compression, I'd say. The brain will tend to evolve data-compression schemes if these reduce the number of neurons needed for processing (I hereby assume that they always do), because neurons are metabolically expensive to maintain and evolution favors parsimony in the use of metabolic energy.

Ultimately, the efficiency of the Laplace transform seems to come from the fact that naturally-occurring time functions tend to be pretty stereotyped and repetitious: a branch nodding in the wind, leaves on it oscillating independently and more rapidly, the whole performance decaying exponentially to stillness with each calming of the wind; an iceberg calving discontinuously into the sea; astronomical cycles of perfect regularity; and a bacterial population growing exponentially, then shifting gears to a regime of ever-slowing growth as resources become limiting, the whole sequence following what is called a logistic curve.

Nature is very often described by differential equations, such as Maxwell's equations, those of General Relativity, and Schrodinger's Equation, the three greats. Other differential equations describe growth and decay processes, oscillations, diffusion, and passive but non-chemically energy-storing electrical and mechanical systems. A differential equation is one that contains at least one symbol representing the rate of change of a first variable versus a second variable. Moreover, differential equations seem to be relatively easy to derive from theories. The challenge is to solve the equation, not for a single number, but for a whole function that gives the actual value of the first variable versus the second variable, for purposes of making quantitative, testable predictions, thereby allowing testing of the theory itself. The Laplace transform greatly facilitates the solution of many of science's temporal differential equations, and these solutions are remarkably few and stereotyped: oscillations, growth/decay curves, and simple sums, magnifications, and/or products of these. Clearly, the complexity of the world comes not from its temporal information, but from it's spatial information. However, spatial regularities that might be exploited for spatial data compression are weaker than in the temporal case.

The main regularity in the spatial domain seems to be hierarchical clustering. For an example of this, let's return to the nodding branch. Petioles, veins, and teeth cluster to form a leaf. Leaves and twigs cluster to form a branch. Branches and trunk cluster to form a tree. Trees cluster to form a forest. This spatially clustered aspect of reality is being exploited currently in an approach to machine intelligence called "deep learning," where the successive stages in the hierarchy of the data are learned by successive hidden layers of simulated neurons in a neural net. Data is processed as it passes through the stack of layers, with successive layers learning to recognize successively larger clusters, representing these to the next layer as symbols simplified to aid further cluster recognition. This technology is based on discoveries about how the mammalian visual system operates. (For the seminal paper in the latter field, see Hubel and Wiesel, Journal of Physiology, 1959, 148[3], pp 574-591.)

Visual information passes successively through visual areas Brodmann 17, 18, and 19, with receptive fields becoming progressively larger and more complex, as would be expected from a hierarchical process of cluster recognition. The latter two areas, 18 and 19, are classed as association cortex, of which humans have the greatest amount of any primate. However, cluster recognition requires the use of neuron specialist sub-types, each looking for a very particular stimulus. To even cover most of the cluster-type possibilities, a large number of different specialists must be trained up. This does not seem like very good data compression from the standpoint of metabolic cost savings. Thus, the evolution of better ability with spatial information should require many more new neurons than with the case of temporal information.

My hypothesis here is that what is conferred by the comparatively large human cerebral cortex, especially the association cortices, is not general intelligence, but facility with using spatial information. We take it on and disgorge it like water-bombers. Think of a rock-climber sizing up a cliff face. Think of an architect, engineer, tool-and-die maker, or trades person reading a blueprint. Now look around you. Do we not have all these nice buildings to live and work in? Can any other animal claim as much? My hypothesis seems obvious when you look at it this way.

Mere possession of a well developed sense of vision will not necessarily confer such ability with spatial information. The eyes of a predatory bird, for instance, could simply be gathering mainly temporal information modulated onto light, and used as a servo error for dynamically homing in on prey. To make a difference, the spatial information has to have someplace to go when it reaches the higher brain. Conversely, our sense of hearing is far from useless in providing spatial information. We possess an elaborate network of brain-stem auditory centers for accomplishing exactly this. Clearly, the spatial/temporal issue is largely dissociable from the issue of sensory modality.

You may argue that the uniquely human power of language suggests that our cortical advantage is used for processing temporal information, because speech is a spaceless phenomenon that unfolds only in time. However, the leading theory of speech seems to be the Wittgenstein picture theory of meaning, which postulates that a statement shows its meaning by its logical structure. Bottom line: language as currently understood is entirely consistent with my hypothesis that humans are specialized for processing spatial information.

Since fossil and comparative evidence suggests that our large brain is our most recently evolved attribute, it is safe to suppose that it may be evolving still, for all we know. There may still be a huge existential premium on possession of improved spatial ability. For example, Napoleon's strategy for winning the decisive Battle of Austerlitz while badly outnumbered seems to have involved a lot of visualization. The cultural face of the zeitgeist may reflect this in shows and movies where the hero prevails as a result of superior use of spatial information. (e.g., Star Wars, Back to the Future, and many Warner Bros. cartoons). Many if not most of our competitive games take place on fields, courts, or boards, showing that they test the spatial abilities of the contestants. By now, the enterprising reader will be thinking, "All I have to do is emphasize the spatial [whatever that means], and I'll be a winner! What a great take-home!"

Let me know how it goes, because all this is just theory.

#21. Is Higher Math Really Undiscovered Physics? [physics]

PH

Red, theory; black, fact.

This post was inspired by the realization that to progress in physics, we need to accept the Newtonian position that absolute space exists. Not only that, but that it is complicated, like a network, crystal, or condensate. Too many fundamental constants of nature (20, according to Lee Smolin) are required to explain the behaviour of supposedly elementary particles with no internal structures to which such constants could refer.

Thus, the constants must refer to the vacuum between the particles, now more readily understood as a complex medium. Looking at the pattern set by the rest of physics and cosmology, such a medium is more readily understood as a condensate of myriad "space-forming entities." Matter would be flaws in this condensate, entropy left over from its rapid formation. Energy may have the same relation to time: irregularities in its rate of progression.

To theorize about how space formed and what came before it, we have to give up visualization, obviously. I suspect this will be a big deal for most physicists. However, the abstractions of higher math may be an island of understanding already existing on the far side of the spatial thought barrier.

In other words, sets, integers, categories, mappings, etc., may be concrete things, and not abstractions at all. Presumably, our spatial and temporal reality still bears the properties it had from the very earliest stages of the universe, co-existing with later-developed properties, which have enabled mathematicians throughout history to access the deepest levels of description of reality, deeper than space time itself.

Consider set theory. Can the familiar concepts of set, union, intersection, and complement be placed into correspondence with physical processes and objects in today's space time to make a case that set theory is pre-spatial physics, so primordial as to be literally unimaginable if thought of as the rules of a real universe? To get started, we have to begin with Leibniz's monads, the "empty set," now considered a real thing. (If you must visualize these, visualize something ridiculous like Cheereos™ floating in milk, when the bowl has reached the single-layer stage.)

The physical process of binding is prefigured by the set-theoretical operation of union. In the simplest case, two monads combine to form a second-order set.

The physical process of pattern recognition, which is, in essence, energy release, is prefigured by intersection. Note that with intersection, the internal subset structure of the set is important, suggesting that the "operating system" of the universe at this stage must keep track of such structures.

We can associate a size measure with a set, namely the total of all the monads inside it once all subsets have been accounted for. The usefulness of numbers in dealing with the world is explained if this size measure is the basis of laws governing what sets may combine as unions and in what frequency (i.e., fraction of all sets extant.)

The fact that most of physics seems to be governed by differential equations may be prefigured by a tendency of these combining laws to depend on the difference of two sizes. The set-theoretical operation of complementation may prefigure the existence of positive and negative charge and the Pauli exclusion principle of fermions, on which molecular complementarity interactions depend.

#20. The Two-clock Universe [physics]

PH

Red, theory; black, fact.

The arrow of time is thought to be thermodynamic in origin, namely the direction in which entropy (disorder of an isolated system) increases. Entropy is one of the two main extensive variables of thermodynamics, the other being volume. I would like to propose that since we live in an expanding universe, the direction of cosmological volume increase makes sense as a second arrow of time; it's just not our arrow of time.

One of the outstanding problems of cosmology is the nature of dark energy, thought to be responsible for the recently discovered acceleration of the Hubble expansion. Another problem is the nature of the inflationary era that occurred just after the Big Bang (BB), introduced to explain why the distribution of matter in the universe is smoother than predicted by the original version of the BB.

Suppose that the entropy of the universe slowly oscillates between a maximal value and a minimal value, like a mass oscillating up and down on the end of a spring, whereas the volume of the universe always smoothly increases. Thus, entropy would trace out a sinusoidal wave when plotted against volume.

If the speed of light is only constant against the entropic clock, then the cosmological acceleration is explainable as an illusion due to the slowing of the entropic increase that occurs when nearing the top of the entropy oscillation, just before it reverses and starts down again. The cosmological volume increase will look faster when measured by a slower clock.

The immensely rapid cosmological expansion imputed to the inflationary era would originate analogously, as an illusion caused by the slowness of the entropy oscillation when it is near the bottom of its cycle, just after having started upward again.

These ideas imply that entropy at the cosmological scale has properties analogous to those of a mass-and-spring system, namely inertia (ability to store energy in movement) and stiffness (ability to store energy in fields). The only place it could get these properties appears to be from the subatomic particles of the universe and their fields. Thus, there has to be a hidden network of relationships among all the particles in the universe to create and maintain this correspondence. Is this the meaning of quantum-mechanical entanglement and quantum-mechanical conservation of information? However, if the universe is closed, properties of the whole universe, such as a long circumnavigation time at the speed of light, could produce the bounce.

These ideas also imply the apocalyptic conclusion that all structures in the present universe will be disassembled in the next half-period of the entropy oscillation. The detailed mechanism of this may be an endothermic, resonant absorption of infrared and microwave photons that have circumnavigated a closed universe and returned to their starting point. Enormous amounts of phase information would have to be preserved in intergalactic space for billions of years to make this happen, and here is where I depend heavily on quantum mechanical results. I have not figured out how to factor in the redshift due to volume expansion.&&

#4. My First Theory of Everything (TOE) [physics]

PH

Red, theory; black, fact.

The nucleus around which a TOE will hopefully crystallize.

Alocia and Anaevia

In my first post, I made a case for the existence of absolute space and even suggested that space is some kind of condensate (e.g., a crystal). The divide-and-conquer strategy that has served us so well in science suggests that the next step is to conceptually take this condensate apart into particles. The first question that arises is whether these particles are themselves situated in an older, larger embedding space, or come directly out of spacelessness (i.e., a strange, hypothetical early universe that I call "Alocia," my best Latin for "domain of no space." Going even further back, there would have been "Anaevia," "domain of no time." Reasoning without time seems even trickier than reasoning without space.)

What came before space?

The expansion of our universe suggests that the original, catastrophic condensation event, the Big Bang, was followed by further, slower accretion that continues to this day. However, the resulting expansion of space is uniform throughout its volume, which would be impossible if the incoming particles had to obey the rules of some pre-existing space. If there were a pre-existing space, incoming particles could only add to the exterior surface of the huge condensate in which we all presumably live, and could never access the interior unless our universe were not only embedded in a 4-space, but hyper-pizza-shaped as well. The latter is unlikely because self-attraction of the constituent particles would crumple any hyper-pizza-shaped universe into a hypersphere in short order. (Unless it spins?) Conclusion: the particles making up space probably have no spatial properties themselves, and bind together in a purely informational sense, governed by Hebb's rule. 

Hebb's rule was originally a neuroscience idea about how learning happens in the brain. My use of it here does NOT imply that a giant brain somehow underlies space. Rather, the evolutionary process that led to the human brain re-invented Hebb's rule as the most efficient way of acquiring spatial information. 

Hebb's rule pertains to signal sources: how could hypothetical space-forming particles come up with the endless supply of energy required by pumping out white noise, waves, etc., 24/7? Answer: these "particles" are the growing tips of time lines, that themselves grow by an energy-releasing accretion process. The chunks that accrete are variable in size or interrupted by voids, so timeline extension has entropy associated with it that represents the signals needed by Hebb's rule.

I am well aware of all the space-bound terms in the previous paragraph (underlined), supposedly about goings-on in Alocia, the domain of no space; however, I am using models here as an aid to thought, a time-honored scientific technique.

Is cosmological expansion some kind of accretion?

I imagine that Alocia is home to large numbers of space-like condensates, with a size distribution favoring the microscopic, but with a long tail extending toward larger sizes. Our space grows because these mostly tiny pre-fab spaces are continually inserting themselves into it, as soon as their background signal pattern matches ours somewhere. This insertion process is probably more exothermic than any other process in existence. If the merging space happens to be one of the rarer, larger ones, the result would be a gamma ray burst bright enough to be observed at cosmological distances and generating enough pure energy to materialize all the cosmic rays we observe.

The boundary problem

I suspect that matter is annihilated when it reaches the edge of a space. This suggests that our space must be mostly closed to have accumulated significant amounts of matter. This agrees with Hawking's no-boundary hypothesis. The closure need not be perfect, however; indeed, that would be asking a lot of chance. Imperfections in the closure of our universe may take the form of pseudo-black holes: cavities in space that lack fields. If they subsequently acquire fields from the matter that happens to hit them, they could evolve to closely resemble super-massive black holes, and be responsible for nucleating galaxies.

Conclusions

• Spatial proximity follows from correlations among processes, and does not cause them.
• Any independence of processes is primordial and decays progressively.
• The universe evolves through a succession of binding events, each creating a new property of matter, which can be interpreted as leftover entropy.
• Analysis in the present theoretical framework proceeds by declaring familiar concepts to be conflations of these properties, e.g., time = change + contrast + extent + unidirectional sequence; space = time + bidirectional sequence.