Minding the Planet

Good Article on Loop Quantum Gravity -- New Approach to Physics

The New Scientist published a nice overview of the emerging theory of Loop Quantum Gravity. I've been following this for a number of years, ever since my friend Bram turned me onto it. It's related in some ways to other models of discrete space-time, such as cellular automata and digital physics.

LEE SMOLIN is no magician. Yet he and his colleagues have pulled off one of the greatest tricks imaginable. Starting from nothing more than Einstein's general theory of relativity, they have conjured up the universe. Everything from the fabric of space to the matter that makes up wands and rabbits emerges as if out of an empty hat.

It is an impressive feat. Not only does it tell us about the origins of space and matter, it might help us understand where the laws of the universe come from. Not surprisingly, Smolin, who is a theoretical physicist at the Perimeter Institute in Waterloo, Ontario, is very excited. "I've been jumping up and down about these ideas," he says.

This promising approach to understanding the cosmos is based on a collection of theories called loop quantum gravity, an attempt to merge general relativity and quantum mechanics into a single consistent theory.

The origins of loop quantum gravity can be traced back to the 1980s, when Abhay Ashtekar, now at Pennsylvania State University in University Park, rewrote Einstein's equations of general relativity in a quantum framework. Smolin and Carlo Rovelli of the University of the Mediterranean in Marseille, France, later developed Ashtekar's ideas and discovered that in the new framework, space is not smooth and continuous but instead comprises indivisible chunks just 10^-35 metres in diameter. Loop quantum gravity then defines space-time as a network of abstract links that connect these volumes of space, rather like nodes linked on an airline route map.

From the start, physicists noticed that these links could wrap around one another to form braid-like structures. Curious as these braids were, however, no one understood their meaning. "We knew about braiding in 1987," says Smolin, "but we didn't know if it corresponded to anything physical."  Read More

                                                                                                                                                                                                                   

A Possible Future of Physics

Today I read this nice article which provides a short consumer-friendly overview of the history of the Digital Physics paradigm. Digital Physics is not mainstream physics -- but it is growing and someday could become huge. It brings together computer scientists and physicists in an interdisciplinary approach to physics. While many advocates simply take the position that some physical processes resemble computations, the most extreme would go so far as to posit that the universe is actually a giant computation taking place on some sort of primordial computing fabric.

I've been involved with this field since the 1980's when, as a college student at Oberlin, I got interested in cellular automata as a tool for modelling both the brain and the universe. This led to summer research on cellular automata simulations of physical systems on the CAM-6 parallel processor at the lab of Tomasso Toffoli and Norman Margolus at MIT. They were among the first experimentalists in the digital physics field -- running massive cellular automata simulations of fluid dynamics, population biology, optics, and spin glasses, among other things. Since then I've had the opportunity to spend some time with both Ed Fredkin and Stephen Wolfram, discussing the future of digital physics and the quest for a Theory of Everything.

I think that the Digital Physics is the The Next Revolution in physics. But it may still be another 50 to 100 years before it really takes root. But it's just the beginning of what I think may be an ongoing process of future physical models. Below, I speculate about where this trend will lead us (disclaimer: Wild Speculation ahead: Read at your own risk!)

Brain Has Particular Neurons for Recognizing Celebrities and Other Concepts

In a very interesting new finding, researchers have discovered the people's brains contain individual neurons, or small groups of neurons, that seem exist only to recognize particular people or concepts. This would imply that there is one neuron, or at least a small group of neurons, in our brains for every unique thing that we know. However, that raises certain questions -- for example, if this is true, then the brain should be a lot larger since there wouldn't be room to represent everything a typical adult knows with unique neurons in that amount of space. On the other hand, perhaps the memories are not stored on the neuronal level at all, but instead are stored and computed on the sub-neuronal tubulin "quantum computing" level, which is the subject of much research these days. For more on that check out this book on research into quantum computing in the brain (found by: Josh).

Simulated Universes and the Nature of Consciousness

Researchers in Europe have completed the first phase of what may be the largest computational physics experiment in history: They built and ran a simulated universe through 14 billion years of development. The experiment used up 25 million megabytes of memory, and the biggest supercomputer in Europe for a month. The result was a "Cube of Creation" of 20 billion light years per side, containing 20 million simulated galaxies. Now they're studying it to see what evolved. They hope to gain insights into the function of black holes, and other cosmological principles. This is an amazing piece of work -- definitely the future of cosmology research.

In previous articles, I've speculated that our own universe might also be such a simulation, perhaps run by a much more advanced civilization in a meta-universe outside ours. But in fact, I think our universe is probably quite different from a mere computer simulation (despite how cool it would be if it were a computer simulation!) -- because I don't believe we can explain everything there is in terms of information and computation: I think consciousness doesn't fit in that model.  After exploring this issue for more than 20 years from the perspectives of computer science and physics, philosophy and religion, I've come to believe that consciousness cannot be reduce to, or emerge from, information or computation. As far as I can tell, it's something at least as or more fundamental than space, time, matter and energy. I would even go so far as to say that we won't ever really understand what the universe is or how it develops or functions without first understanding consciousness much more deeply.

Cool Visualizations of Electromagnetic Fields

These visualizations were produced at MIT -- they look like modern art but are actually visualizations of electromagnetic fields. Pretty!

Creator of Sim City Previews Amazing New Game

Many years ago I spoke with Will Wright -- one of the most interesting visionaries I've met (and who happens to be the creator of Sim City) about his dream of a universe game -- one in which the player could evolve life from the simple cellular level all the way up through galactic scale civilizations. Well it seems he has been busy working on this dream, and it sounds fascinating. He previewed it recently at a meeting of game designers, where he discussed the emergent, unpredictable and open-ended nature of the game, which is called Spore. When I spoke to Will about this years ago, I remember that he spoke of wanting to create a game that would enable players to experience the wonder and creative potential of the universe at all levels of scale. It sounds amazing, I can't wait to try it.

Cell chip coming soon

Big news coming -- a radical high-performance, ultra-miniaturized parallel processing chip is about to go mainstream in a variety of consumer devices, giving Intel some serious competition...

Semiconductor designers from International Business Machines, Sony and Toshiba will reveal on Monday the inner workings of a “supercomputer on a chip” they claim could revolutionise communications, multimedia and consumer electronics.

The Cell microprocessor has been under development by the three companies since 2001 in a laboratory in Austin, Texas.

Its unveiling at the International Solid State Circuits Conference in San Francisco has been eagerly awaited and products containing Cell including Sony's PlayStation 3 games console are expected as early as next year.

Advance reports suggest the chip is significantly more powerful and versatile than the next generation of micro-processors announced by the consortium's competitors, Intel and AMD.

The two leading chipmakers are just moving from 32-bit to 64-bit computing and to dual-core processors essentially two “brains” on a single chip.Cell is understood to have at least four cores and be significantly faster than Intel and AMD chips.

“This is probably going to be one of the biggest industry announcements in many years,” said Richard Doherty, president of the Envisioneering research firm. “It's going to breathe new life into the industry and trigger fresh competition.”

Read the full article here

Artificial War

Here is a book that readers who are interested in multi-agent systems will find useful. The author, Andrew Ilachinski is also a reader of this blog, by the way -- it's called "Artificial War: Multiagent-Based Simulation of Combat" and provides an examination of the thesis that what happens on a battlefield (though the arena can be much more general of course) is a self-organized emergent phenomenon that can be understood, at least in part, by examining relatively "simple" underlying rules. In essence, mobile cellular automata. The book summarizes work that dates back to 1997 and was sponsored at different times by the US Marine Corps and Office of Naval Research. Among many applications of this research -- consider the applications for computer games and simulations, as well as for visual effects (think, even more realistic epic battle scenes and crowds).

Anyway, here's the link

TOC and index can be downloaded here

Was our Universe Created in a Lab???

Here's an interesting article on another theory that suggests our universe is just an experiment in someone's lab.

How to Build a Network Automaton

Here is a cool new kind of complex system I am thinking about a lot that we might call a "network-automaton" or a "graph automaton" -- a system that evolves networks (graphs) over time. This rule is similar to cellular automata rules such as the famous "Life" rule discovered by John Conway, however instead of computing the states of cells on a grid, it computes the shape of a network. In a nutshell this system applies a simple local rule at each node in a network that determines what other nodes it should connect to in the next step of time as a function of the connections each of those nodes had in the previous step of time. This yields complex network structures and interesting dynamical emergent behaviors over time -- networks that grow and change as time goes by, networks in which there may even be stable or cyclical topological patterns that move across the network, as well as interactions between such patterns (topological interactions) that resemble the interactions between fundamental particles.

 

Network automata of the sort I propose here may be useful for modeling the structure and dynamics of a wide range of systems from physical systems, to biological systems, to the growth and development of computer networks, to social networks, business networks, and other types of higher-order networks.

 

(By the way -- I would really like an open-source application -- in Java perhaps -- for generating and visualizing network automata rules such as those in this article. If you are a good programmer and would like to volunteer to make some software that can simulate the dynamics of the class of systems I propose here, please email me! I think this will be a very interesting avenue of exploration, and such a tool could be extremely useful.)

See the rest of this article for a detailed description of how to build a working network automaton....

9 Block Pattern Generator -- Try it

This is a really nice visual pattern generator based on quilt patterns. Try it out.

The Physics of the Web

This is a very good article on the physics of scale-free networks such as the Web.

Lately I have been getting increasingly interested in graph theory and also in knot theory. There is a similarity between networks and knots and it should be possible to do a mapping such that the theorems and algorithms of knot theory could be translated to apply to network topologies. I'm sure someone is already working on this, but it's worth pointing out. For example, many networks could be viewed as planar projections of knots (the shadows that knots cast on a plane). I have also been thinking about the subject of loop quantum gravity which I learned about from my friend Bram Boroson.

All of this connects to an idea that I've been thinking about lately for a new kind of discrete system for evolving topologies that I call a "loop automata" -- basically the idea is to use networks of interlinked loops as the fundamental building blocks for evolving spaces, and the dynamics within them. In my conception of a "loop automaton" the points at which loops intersect ("crossings," to use knot theory terminology) are "nodes" and the segments of loops between intersections are "arcs." So using a single construct we can have both nodes and arcs in our model. In other words we can construct graphs out of systems of interlinked loops.

Loops can have various states (a simple model might have a single valued state for the "energy" of the loop, while more complex models might deal with oscillation frequencies or even shapes of loops) The next step is to design functions on such networks of loops that modify the state of each loop based on the states of loops it intersects with (it's neighborhood). This function should govern the creation, destruction, linking and unlinking of loops, as well as the states of loops. By specifying either that all loops are fixed diameter (regardless of what other loops they intersect with) or that loops can only intersect other loops in a single point (in other words that intersecting loops are never on the same plane) then we can interpret the resulting network of loops as a space that must have one of a set of certain dimensions and shapes. This enables such a system to represent any potential space. Information propagates along such spaces as the states of loops interact, causing feedback between the topology and the energy state of space.

In such models, every pair of directly connected nodes have two arcs connecting them -- one in each direction (I assume that all loops are directed arcs that circle back on themselves endlessly). This enables information to propagate along different paths in different directions, enabling a form of "social interaction" between nodes. For example, imagine that every loop is a little clock around which a single pulse of energy is circling at some frequency. Whenever the pulse passes through an intersection point with another loop (ie. through a node) an interaction takes place between the two loops. This has the effect of modifying the state of the loop we are looking at such that as the pulse continues from that point onwards around the circumference of the loop it may have a different frequency. In other words, as the pulse goes "to" a node it has some state, and as it returns back "from" that node it may have a different state. This "back and forth message passing" takes place between directly connect loops as well as along transitive chains of loops.

Unless you spend a lot of time thinking about networks, graphs, knots, cellular automata and digital physics all of the above is probably incomprehensible. I apologize for the "rough" sketch but these are preliminary ideas at this stage. Still, from my reading on knot theory, graph theory and other related subjects I am starting to see a pattern here. Perhaps using loops as the fundamental building blocks of networks is not such a bad idea.

Chaotic Computing - Alternative to Quantum Computing?

A new approach to computing called Chaotic Computing has been proposed. It uses chaotic elements to simulate logical operations. The benefits are that such systems may be dynamically reconfigurable in real-time, and may be able to perform multiple operations at the same time. This may be an alternative to quantum computing. It may also be how our brains work.

Finding Primes Using Cellular Automata

It just occurred to me that distribution of primes looks VERY much like the output of a cellular automaton rule. This makes me wonder whether it might be possible to use a cellular automaton to generate prime numbers. If we can find the rule that generates the prime numbers, perhaps this rule has other important properties. Just a hunch. In any event, it would help to explain the distribution of primes. Below I discuss some approaches to doing exhaustive searches for CA rules that generate the primes.

A New Way to Find Patterns in Distributions of Numbers

This evening I had an interesting idea for a new way to look for patterns in the distribution of numbers such as the prime numbers and the digits of Pi. In a nutshell I propose that there may be patterns in these number sequences that might not be evident to a computer but could be evident to the human eye and human intelligence, which among other things is tuned to find order in chaos, even when that order is "fuzzy." In this article I propose a new class of rules that are similar in some respects to cellular automata, for generating visualizations of the distribution of numbers, and for leveraging distributed human intelligence to evalute those visualizations for meaningful patterns.

Social Networks, Physics, Civilizations -- Do they All Obey the Same Underlying Rules?

I am having an interesting conversation with Howard Bloom, author, memeticist, historian, scientist, and social theorist. We have been discussing network models of the universe and the underlying "metapatterns" that seem to unfold at every level of scale. Below is my reply to his recent note, followed by his note which is extremely well written and interesting...

------------
From: Nova Spivack
To: Howard Bloom
Subject: Re: Graph Automata -- Is the Universe Similar to a Social Network?

Howard, what a great reply!

Indeed the metapattern you point out seems to happen at all levels of scale. I am looking for the underlying Rule that generates this on abstract graphs -- networks of nodes and arcs.

In thinking about this further, I think we live in a "Social Universe." What binds the universe together, and causes all structure and dynamics at every level of scale, is communication along relationships. Communication takes place via relationships. And relationships in turn develop based on the communication that takes place across them.

Relationships and communications take place between locations in the manifold of spacetime, as well as between fundamental particles, cells, people, ideas, network devices, belief systems, organizations, economies, civilizations, ecosystems, heavenly bodies, galaxies, superclusters, or entire universes. Whether you call it "gravitation" and "repulsion" and other forces are really just emergent properties of the dynamics of relationships and communications. It's really all very self-similar.

I believe that we can make an abstract model of this -- just a graph comprised of nodes connected by arcs -- where the nodes (and possibly the arcs too) have states, and information may travel across them. Then, at each moment in time, we may apply simple local rules to modify the states of nodes and arcs in this network based on their previous states and the states of their neighbors.

Graph Automata -- What Can Social Networks Teach us About Underlying Physical Laws?

Hello all, I have been thinking about the general problems of social networks on the Internet. It occurs to me that these issues are closely related to digital physics. For more on digital physics see the work of Ed Fredkin, Stephen Wolfram, Norman Margolus, Tomasso Toffoli, and other pioneers of the field of cellular automata.

In the past I have worked informally on cellular automata at MIT in the lab of Fredkin, Margolus and Toffoli -- and in particular that led me to get interested in what could be called "graph automata" -- rules that operate on arbitrary graphs in a manner that is similar to the way that cellular automata operate on cells in rigidly defined neighborhood topologies. The general concept is that the structure of a graph can be optimized for various parameters in a bottom-up, iterative, emergent fashion by running local rules at each node based on the neighborhood structure around each node (taking into account the number of arcs around each node, the directionality of arcs if any, and the states of nodes if any). There is a general class of rules that we could call "graph automata" that are quite interesting to study because in many ways they are better metaphors for physics than simple CA's, in my opinion.

In any case, that's not the point of this note. Instead, I would like to propose that one way to discover the "general laws" of digital physics might be to study social networks. Social networks are an interesting "macro-level" phenomenon that could be considered to be useful analogs for discovering the general properties of physical information networks. They are comprised of nodes connected by arcs in which information flows. We could view all physical systems through this lens and perhaps learn quite a bit from this approach.

Optimization of Social Network Architectures Using Tiling Rules

Here's an interesting follow-up thought on my suggestion of some Hypothetical Laws of Social Networks.

What if in fact there is an entirely new way to design social networks, based on the mathematics of tilings? A tiling is a method of filling a space with geometric shapes. For example, you can tile a space with squares, hexagons, quasicrystals, spheres, etc. -- depending on the dimensions and topology of the space.

Awareness Is Not What You Think -- The Zen State Automaton

No computer will ever be able to experience the state of Enlightenment that is familiar to Zen monks and other Buddhist meditators. If a computer is ever going to be truly intelligent -- at least in the same way that humans are -- it must be able to have religious experiences that are the same as those that humans have. The particular religious experience I am speaking of is the realization of the emptiness that is considered to be one of the fundamental truths of eastern philosophical traditions such as Buddhism and Taoism.

According to Buddhist teachings, the pure realization of emptiness is free of any form, substance, nature, characteristics, or content -- yet it is not a mere nothingness. Rather it is said to be fully awake and lucid yet totally beyond the limitations of dualistic consciousness. It contains no thought, no cognitive formations, no sense of identity or self-reflection, no perception --- in short it is totally free of any conceptuality. This is said to be the natural state of being, or the actual nature of mind itself when not obscured by conceptual overlays.

Computer systems, such as hypothetically sophisticated future artificial intelligence programs, will never be able to actually experience authentic religious experiences and will probably never be able to simulate them either -- no matter how "advanced" they are as software programs. This is because computers cannot do anything without using information -- computers are nothing but information processors. In other words, information processors are not capable of simulating or having states that contain no information content. The state of emptiness however is a state that is devoid of information content and is therefore not something that a computer will ever authentically realize. A similar religious experience that is considered to be the final level of spiritual evolution, and the highest realization, in Buddhism, is omniscience -- that state of being all-knowing, which is one of the qualities of a fully enlightened being. Omniscience is a state that is totally infinite -- it contains all information instantaneously. Computers on the other hand cannot process infinite information in finite time and can therefore not become omniscient. These are just two of many types of religious experience that are simply impossible for any computer or software program to generate. While computers and programs might be able to simulate such experiences, these simulations will never the same as the "real thing."

Simulated awareness or consciousness in a computer is not capable of replicating a state without information content. At best, a computer could simulate a lack of sensory input and a lack of cognitive formations -- but in order for that computer to be able to know that this was taking place it would have to create some infomration to represent that fact and then process that information in order to know that fact. In other words a computer can simulate emptiness but that is not the same as actual emptiness. A computer's simulation of emptiness is similar to the statement this sentence does not exist. We can say that all we like, but the mere act of saying it contradicts its meaning. In the same way, in order for a computer to simulate and know the experience of emptiness it must be in a state that is not equivalent to the state of experiencing emptiness.

Humans and other truly sentient beings are not limited in this way. We are capable of knowing emptiness directly because emptiness and awareness (that which knows) are in fact the very same thing. When a sentient being experiences emptiness it is unmediated by any information process -- emptiness is the experience of the very nature of self-awareness. In other words, because we are truly aware and our awareness is inherently aware of awareness, we are capable of being aware of emptiness which is the actual nature of awareness in its pure form (when unclouded by conceptual overlays). The point here is that when a sentient being has a direct realization of emptiness it does not take place through any conceptual process, in fact it is the opposite of a conceptual process, by definition. The experience of emptiness is a direct realization of the non-conceptual, contentless ground that underlies consciousness. Conceptual thought is merely a process of mental projection taking place on the basis of that ground. Computers are only capable of conceptual activity (although primitive at best). Computers are not capable of representing or experiencing a truly non-conceptual state of being.

For this reason, no computer will ever be truly self-aware in the same way that humans are. No computer will ever be able to experience the state of emptiness. No computer will ever be able to synthesize awareness. The Dalai Lama has mentioned in the past that someday, once computer become sophisticated enough, they may be able to support mindstreams, such that a consciousness could conceivably incarnate into such a machine. But that is very different from saying that the machine is conscious or that consciousness has been synthesized by the machine.

True consciousness, true awareness, does not emerge from any formal information process. It is fundamental to the universe. In other words, awareness does not come from something or somewhere -- it is already there and always has been. Just like energy. We never create it, it has always existed and we merely move it, transform it, and channel it from point to point.

Similarly, the human body and brain do not create conscious and are not themselves conscious either, for they are just organic machines. No machine, whether organic or silicon is really conscious in its own right. Any conciousness that appears on the basis of such machines is merely temporarily associated with them and totally independent of them. Consciousness is totally separate from machines, and from brains and bodies. It is a mystery. It always has been. It always will be. While it may arise within such systems it is not caused by them, not synthesized by their components, and cannot be reduced to them. In other words, a Zen State Automaton is impossible.

My argument goes as follows:

The Zen State Automaton

1. A human being (a truly self-aware system) can be aware of their own awareness without any thoughts occuring (ie. without creating or using any information)

2. Computers cannot do anything (thus they certainly cannot sense or know anything) without using information.

3. Therefore computers will never be able to synthesize or replicate self-awareness using any information process. This proves that computers will never be self-aware or conscious in the same way that truly aware beings (such as humans) are. Without true self-awareness computers will never be truly intelligent -- at least not as intelligent as systems that are truly self-aware. Therefore, artificial intelligence will never be truly intelligent by human standards.

In other words, a Zen State Automaton is impossible.

read more...

Wolfram Presses on With Digital Physics: Post-Cellular Automata Conference Roundup

I spent many years working on cellular-automata models of the universe. Inspired by Ed Fredkin's theory that the universe is a computer, I ended up doing an internship in his lab at MIT. Later, while working at Thinking Machines, I met Stephen Wolfram. Earlier this year Stephen and I spent a few hours talking about network models of cellular automata as well as the business potential of CA technologies -- for example, in the field of nanotech. This article provides a basic overview of the digital physics paradigm, as well as some examples of recent work and tidbits from Wolfram's recent "A New Kind of Science" conference in Boston.

Are the Laws of Physics Changing with Time?

This article discusses the notion that the laws of physics may be evolving. I spent a great deal of time during and after college trying to model this phenomenon using a new class of cellular automata that I came up with. In my conception, I wanted to design a cellular automaton that started out with no assumptions about the topology of space, the state of space, or the underlying physical laws (the CA rule, in this case). So I created a meta-cellular-automata framework in which these characteristics could emerge from a single higher-level meta-rule applied recursively to itself over time. In other words, the energy state of space at a given time was interpreted as a specification for the rule (the physical laws) to be applied to that same space at the next step in time. The rule modifes the state of links between nodes, as well as the states of nodes. The link-states are interpreted as the topology, the node-states are interpreted as the energy at each location. The model is very elegant, but probably would not be comprehensible to anyone who is not already familiar with cellular-automata and neural network models. Let me know if you want to discuss it.