A Theory of Consciousness

Lately, I’ve been reading Oliver Sacks’s new-ish book Musicophilia. While it’s not quite the tour de force that The Man Who Mistook his Wife for a Hat was, it’s gotten me thinking once again about the neurology of consciousness, and after a few days’ contemplation (and a few years spent reading neurological books), I think I finally have a rough sketch for my own theory of how consciousness comes into existence. Of course, I’m not a neurologist. I don’t know the details of how all this works, and none of it is based on empirical evidence, but that’s the beauty of the Internet: you can talk about ideas abstractly. And, since that’s what I’m good at, that’s what I’m going to do. So, here goes: consciousness.

There are a few structures which are vital to conscious experience. These are:

• The thalamus
• The brainstem
• the prefrontal cortex (and the rest of the cerebral cortex as well)

The other structures are more involved in the contents of consciousness. They are the raw material that the conscious structures process. Here’s how it seems to me that consciousness happens:

1. Sensory information enters via the brainstem.
2. The brainstem preprocesses the information and sends it to the thalamus.
3. The thalamus takes in the preprocessed sensory information and combines it with information about the state of the cortex itself.
4. The thalamus relays this information to the relevant cortical structures. The prefrontal cortex may play a role here in organizing the arrival of the information, and perhaps in weighting it emotionally.
5. The cortex processes the sensory information, and the prefrontal cortex reads the results and generates judgments based on emotional weighting from the limbic system. It may generate some of its own emotional reactions as well.
6. The prefrontal cortex sends the interpreted brain state back to the thalamus. There may also be other loops between the thalamus and the other cortical regions.
7. The processed mental state enters the thalamus, along with a new set of sensory information.
8. Repeat.

Of course, this says nothing about memory formation, which is very important for making sense of conscious awareness. It just so happens that I have a theory for how memories form as well.

1. An emotional signal is sent by the amygdala (or some other part of the emotional system) to the hippocampus, which “reads” sensory information currently being process, thus forming connections between the disparate kinds of information.
2. This association is stored in the temporal lobe. When the area where the memory structure is stored is activated, the temporal lobe re-activates the relevant structures (those whose particular activity patterns were linked by the hippocampus), and the remembered event is re-experienced.

I’m not really sure how a memory would be recalled in this model, though. I’d venture to guess that it’d have something to do with the prefrontal cortex sending a signal to the temporal lobe, in order to retrieve the memory for comparison to current events.

This little model (and I’ll say it again, I’m not a neurologist. Not even close, so think about this model in the spirit in which it was intended: as a useful idea, not as anything approaching a theory) does shed some useful light on certain kinds of mental illness and the effects caused by certain sorts of brain damage.

• Schizophrenia: It’s well known that in schizophrenia, the prefrontal cortex is not functioning as it should. Without a properly-functioning cortex, judgments based on memories and sensory information cannot be made properly, and sensory information does not get integrated properly. Also, the prefrontal cortex’s inhibitory connections are less functional as well, which would seem to explain not only the disorganized and unintegrated thought patterns associated with schizophrenia, but also the hallucinations, which could be the result of sensory information going to the wrong place or being integrated improperly. Or, perhaps, the hallucinations and delusions might have something to do with the fact that, without prefrontal cortical direction, the various cortical structures can no longer properly regulate their output.
• Anterograde amnesia: with damage to the hippocampus comes difficulty forming long-term memories. In this model, that would be because the structure which associates the various neural states with one another is either incapable of doing so, or else it is incapable of moving them into the temporal lobe for permanent storage.
• Thalamic coma: this may also apply to comas in general, as well as minimally-conscious states, but thsi model only really has something to say about thalamic comas. When the thalamus is damaged, not only can external sensory information not enter the cortex, but the cortical state itself is also prevented from being communicated to the cortex, so there is an absence of both sensation and cognition. The thalamus, however, is divided into two parts, one of which communicates primarily to the cortex, and the other of which is mostly responsible for preprocessing and relaying sensory information. If only the sensory-preprocessor (in the case of vision, this is the lateral geniculate nucleus) were to be damaged, the patient would still likely be able to achieve conscious awareness, but there would simply be no sensory information for them to process.
• Encephalitis lethargica: in patients with this disorder (which is, according to Oliver Sacks, an extreme form of parkinsonism), the patient is mostly functional, but they are unable to initiate much activity (if any). In this model, that would be because of damage or inactivity of the limbic system, which is crucial in communication emotional meaning to the prefrontal cortex. In patients with severe parkinsonism, there may be difficulty seeing the relevance of actions, and therefore, the actions are not generated. This can also occur with certain kind of brainstem and prefrontal lesions.
• Depression: in this disease, the prefrontal cortex is known to be less active. However, unlike in schizophrenia, its integrative functions must still be intact. However, its emotional functions become impaired, leading to difficulty forming memories (since the PFC cannot communicate the emotional necessity of remembering something to the hippocampus, and would likely have difficulty sending retrieval signals, too), lack of motivation (since the significance of actions would become unclear), and depressed mood or flat affect (since everything would have the same emotional significance).

I won’t go any further, for fear of over-inflating my ego and for starting to make claims that I have no hope of arguing for. But this, I think, is at least something to get people thinking. Of course, there are a billion things that I haven’t taken into account: the left versus right hemisphere functional disparity, the effects of neurotransmitters, and no doubt I’ve left out quite a few very important brain structures.

Evolving Behavior

Well, since my previous posts about my various NetLogo models have been so popular, I thought I’d write another one about one my most unusual — and in-depth — NetLogo models thus far: one to simulate the evolution of behavior.

This particular simulation sprang from a desire I’ve harbored for a long time to create “digital organisms,” as Wikipedia calls them: organisms whose behavior is controlled by internal programming instructions, which evolve over time in a simulated environment. Of course, it’s notoriously difficult to both manipulate text and run it as program instructions within a programming language (at least for me), unless you’re willing to code a mini-compiler within your program, but nonetheless, I thought I’d give it a try.

As it turns out, NetLogo already comes with a built-in method called run. When called with a string as its argument, run interprets the string as it would any other stream of NetLogo commands. Given that, and the elegant modular simplicity of the NetLogo language, it seemed that even a merely casual programmer such as myself might have some chance of building a digital-organism simulator.

Thank goodness for one of NetLogo’s other commands, namely, carefully. Carefully has two arguments: an instruction to run, and a procedure to run if that instruction causes an error. With that in mind, and NetLogo’s modularity, I threw together a simple list containing a handful of symbols (such as “=”, “if”, and “+”), as well as the names of a few methods I’d pre-coded myself (methods that tell the organisms to do things like “eat” and “reproduce”). I had to do the latter because, the only way I could get around the errors that carefully would otherwise cause, at least for the time being, was to make any error-producing organism die immediately. After some fiddling to make the program-mutation procedure work properly, and to fix some other stupid little errors, I finally managed to get it to run. Here is a sample image from the result:

Those little labels you see hovering over each organism are the organisms’ programs. As you can see, they’re neither very varied or very complex. I had hoped to evolve the organisms into greater complexity (note: all of the methods you see here are not built-in to NetLogo, but are references to methods I coded myself. I did this for the sake of simplifying things a bit, and for “chunking” the program, so that it was less likely that a mutation would break the code, since the NetLogo language isn’t terribly mutation-tolerant, I discovered).

Over time, unfit programs died out, and the more fit ones reproduced. After a fairly short run-time, I got this:

Notice how the organisms all have essentially the same code. This is an unintended side-effect of the fact that I spawned so few organisms at the beginning of the run, for the sake of visual clarity. Although, I have noticed that a lot of my randomly-instantiated populations tend to do the same thing, in all of my evolution simulations: most of them will prove unfit, so the world will end up being populated by a group of genetically-similar descendants of the few highly-fit originals.

I let the model run for a little while longer, knowing full well (from other runs) that it wouldn’t do what I was hoping. Apparently, I didn’t make the environment complex enough, or the selection process harsh enough, to necessitate the evolution of interesting programs. The fact that interesting variations almost always die out — since even a misplaced parenthesis or bracket will cause a syntax error, which, as I said above, automatically results in the organism’s death — sort of selected against novel programs. What I was really hoping to see were some strange loophole exploits or programming workarounds (for example, an organism that, say, re-set its own energy level so that it wouldn’t have to trouble with actually eating food) of the kind that I talked about in my previous post “Unexpected Consequences”. What, instead, I ended up with, was this:

(For the sake of readability, I’ve only printed the program of a randomly-selected ten organisms.)

As you can see, every organism has essentially the same program. Oh well, I guess that’s a problem to be tackled in Version 2.

Here are some of my goals for the next rendition:

• Streamlining of the code: When there are more than about twenty-five organisms, the simulation slows waaay down. I don’t know if there’s a way to execute the organisms’ programs faster, but I’ m hoping that I can figure something out.
• Make the programs less fragile: The main roadblock to interesting programming variants is the fact that any “broken” code dies immediately, rather than, perhaps, getting repaired. Figuring out how to do that is going to be complicated, but it seems that every time I think I’m not going to be able to do something in NetLogo, I still manage.
• Make the environment more complex: as it is, the organisms are only competing for two things: energy, and, to a much lesser extent, space. I’d like to see if I can make the space-competition harsher, and perhaps introduce some new resources for them to compete over, such as mates (the current version uses asexual reproduction, since I didn’t want to bother with the nightmare of trying to prevent errors in sexually-combined programs).

More later, as events warrant.

Unexpected Consequences

One of the things that’s always fascinated me the most about simulated evolution is the way in which simulated organisms have a tendency to exploit any loophole or weakness in your code for an evolutionary advantage. Although I’ve designed and attempted to design a handful of evolutionary simulations, I’d never until today seen an example of this Darwinian cleverness.

A few days ago, I threw together a simple little evolution simulator in NetLogo. Each of the agents in the simulation had three genes: xcor (position along the x-axis), ycor (position along the y-axis), breednum (the number of daughter agents it spawns when it reproduces), and killpropensity (how likely the agent is to kill a random nearby agent). The simulation produced some interesting — although not terribly fascinating — behavior: those agents that produced the most offspring had a tendency to dominate. There was an interesting dynamic between the “killer” agents and the “peaceful” agents. The killers tended to form low-density groups (since if any of them were too close together, they’d usually kill each other), while the “pacifists” formed dense blooms. For a while, the killers would hold back the pacifists, but eventually, the pacifists would encroach and squeeze out the killers altogether. A typical run looked like this:

The agents inherit the color of their parents, so the coloration isn’t exactly by “species,” but it’s pretty close. As you can see, the green agents are fast-breeding pacifists, rapidly encroaching on the slower-breeding killers toward the center.

Then — and this is where the unexpected behavior and exploitation of loopholes I was talking about comes in — I introduced a new variable: mutationrate. It controls, obviously enough, how rapidly the agents mutate. Very quickly, every run started to look like this:

As you can see, this blue species has very rapidly come to dominate. You can’t see it, but this species has a rather high mutation rate. It took me a while to figure out why the fast-mutators were at such an enormous advantage. Then, I remembered that, in this simulation, the agents were competing for space, and in such a competition, the fittest organisms would be the ones that can maximize the space filled by their offspring. Since x-position and y-position were treated as genes, they were being mutated right along with the other variables, and since a rapidly-mutating position allowed the agents to jump farther from their parents and fill space more rapidly, fast mutation was an enormous advantage. It was such an enormous advantage that, even though the extremely large mutations the fast-mutators experienced prevented the evolution of any other behavior (because those genes tended to get so randomized that they effectively didn’t get passed on), they were still far more successful than any of the other species.

After I corrected for this ludicrous advantage (by setting it so that mutation rate couldn’t work on the position genes), this is what I got:

For a moment, I thought I’d solved the problem, until I inspected some of the agents and discovered that they had stopped mutating altogether. The sneaky intelligence of the genetic algorithm strikes again! I suppose that mutating would become something of a maladaptive behavior once the organism had optimized all of its other behaviors, since, after optimization was reached, any organism that mutated could only be at a disadvantage.

I realized that the only fix for this would be to force the mutation rate to stay above 2 (it’s a peculiarity of the random-number-generation code I cobbled together for this simulation that, at a mutation rate less than 2, no mutations occur). I thought that all I’d get would be the simulation I started with, but I was pleasantly surprised to discover that there was actually quite a diversity of mutation rates, and that none of these rates was at a particularly huge advantage over any of the others. This is what a run of the fixed simulator produced:

Those numbers you see hovering over every agent are the mutation rate. It appears that there’s not really an advantage to having a mutation rate above the usual 2, but it does seem that there’s not a disadvantage, either. So I can finally call this simulation fixed.

This experience reminded me that there’s a reason genetic algorithms are so popular in AI research, and that brings us to the moral of this little story: Darwinian evolution is a lot smarter than us. When writing evolutionary simulations, if there’s a loophole or a workaround or an exploit to be found in your code, then evolution will find it. Plan accordingly.

NOTE: Someone requested an image with the organisms color-coded by “kill propensity.” Since you asked nicely, and since I agree that that would be a good image to have up here, here you go. The organisms that are the darkest have the lowest probability of killing their neighbors, and the ones that are closer to white are very likely to kill:

As you can see, the situation is as I described in the body of the post: the killers have too great a tendency to limit their own growth, and are easily out-competed by their more peaceful counterparts.

SimHeart — Now Available for Download

All right, as promised, I’ve finally figured out a way that people can download SimHeart to play with it themselves. Many thanks to the folks at NetLogo for automating so much of the process, and thanks to MediaFire.com for the free file hosting.

The file is kind of large because, in order for it to work, I had to put a bunch of Java modules into the folder with it, but it shouldn’t take too long to download, even over a slow-ish Internet connection. When you’ve downloaded it, you’ll need to extract the file to your desktop. I recommend an unzipping program like WinZip or WinAce. The program should (major, major emphasis on should) work on Macs and PCs, but I make no guarantees.

To run the simulation, go into the folder into which you’ve extracted SimHeart, and double click on the HTML file there. It should open up in a new window, and you should see the simulation screen. If you don’t, either you don’t have an up-to-date version of Java, or something went wrong in the download process, or I made a mistake zipping the files. If you checked the previous two things, please leave a comment and describe the problem, and I’ll try to help, although I make no claims to be very good at this kind of thing.

Also, I must provide the obligatory legal disclaimer: I take no responsibility if this file somehow damages your system. To my knowledge, there is absolutely nothing in the file that should do so, but you never know, something might have gotten corrupted or damaged along the way. Also, this software is for entertainment purposes only, and should not be taken as any form of medical advice. I’m not sure why anybody would, but you never know.

Download SimHeart 2.0 here.

If you already have the latest version of NetLogo installed on your computer, you can download the much smaller .nlogo file here. If you’re interested in this kind of thing, you should go ahead and download NetLogo (you can do that here). Not only will it allow you to download a much smaller file, but NetLogo comes with a whole cornucopia of fascinating little simulations, and there are more you can download from the Internet.

If you have trouble with either of these files, please let me know by commenting on this post. If you don’t want to do that for some reason, send an e-mail to asymptote [døt] inverse [át] gmail [døt] com (Sorry about all the weird characters in there, but that account gets enough spam as it is, without ever having broadcast the address on the Internet, so I figured I’d better obfuscate as much as possible).

I’ll try to update the files as I revise SimHeart, but I seem to be at a point where there’s not much more I can do with it, at least not without rewriting most of the code. I’ll be sure to post updates as they come.

SimHeart 2.0

It seems that every time I sit down to work on my heart-simulation project, I get a lot more done than I was expecting. In my last post on the subject, I talked about how I wanted to integrate a more realistic model of the atrioventricular (AV) node, the little bundle of nerve fibers that carries the contraction impulse from the atria at the top of the heart to the ventricles on the bottom. Apparently, I’d entirely misjudged the difficulty of this effort, since, once the solution occurred to me, I was able to implement it in about five minutes.

Here’s what I did. As I said before, each cell in the simulation has two variables assigned to it: ARefrac, which determines whether or not an atrial impulse can pass through the cell; and VRefrac, which determines whether a ventricular impulse can pass through. I solved the AV-realism problem by simply introducing a global variable called AVRefrac that determines whether or not the AV node can accept an impulse. Basically, every time a simulated electrical “spark” strikes the simulated node, as long as AVRefrac is equal to or less than zero, it sets AVRefrac’s value to a user-specified constant I call AV-delay. So, basically, now the ventricles can only respond as fast as the AV node will allow, just like a real heart! When I saw how beautifully my little fix had worked, I was thrilled!

So, my simulated heart is now more realistic than ever. For example, I did a few runs with the refract-length value (the value that determines how quickly cells recover their ability to fire after each firing) set very short so that arrhythmias would occur frequently, so that I could study their effects. Before long, my simulated heart went into atrial flutter/fibrillation (a condition where the small pumping chambers at the top of the heart expand and contract quickly and chaotically, often leading to a dangerously fast ventricular rate. I was amazed to see something very similar to the many atrial-fibrillation EKG’s I’ve looked at:

(Note: in the simulated EKG, I’ve separated the atrial and ventricular signals, since whenever the ventricular rate got very fast, it obscured all the atrial activity, and I wanted to be able to study the atrial activity as well)

Given my tendency towards oversimplified simulations that produce peculiar behavior, the resemblance this bears to real supraventricular tachycardia (fast heart rate caused by the atria, which is often seen in atrial flutter or fibrillation) was frankly, surprising. After about half a second of atrial flutter, the atria begin to fibrillate, producing that classic irregular ventricular response.

Note the extremely high ventricular rate that shows up towards the end of the ECG. That’s a rather unrealistic product of my simulation, since whenever one of the waves of excitation collided with the back of a previous wave, it had a tendency to collapse into a tachycardic or fibrillatory spiral.

There are some forms of supraventricular tachycardia that terminate on their own. They’re called “paroxysmal” supraventricular tachycardia, and my simple little simulation actually managed to produce a run of it!

Some forms of atrial fibrillation occur in the presence of heat block (which, in its most common form, is basically a very slow AV node that doesn’t conduct every impulse that passes to it). In those cases, the fibrillation is frequently asymptomatic or minimally symptomatic, since the heart doesn’t end up racing. When I set the AV-delay parameter higher than usual, I observed this very same phenomenon.

Eventually, the aforementioned wave-collision problem had become annoying enough that I decided to re-write part of the simulation so that there was a small probability that an electrical spark could actually cross a cell that had not entirely recovered. That solved a lot of my problems.

In the re-written simulation, atrial fibrillation still produces that classic irregular ventricular heartbeat, and this time, since the waves are more collision-tolerant, the behavior doesn’t immediately degenerate into ventricular fibrillation, which gives me a chance to actually study it properly.

More updates as they’re warranted. And for those reader(s?) who are wondering what the hell has been wrong with me lately, don’t worry, I’ll be turning the blog over to my old cynical, sarcastic self very shortly.

UPDATE:

I was sitting around without much to do, so I opened up SimHeart and let it run in the background. When I checked in on it again a few minutes later, I’d discovered some very interesting behavior:

Apparently, some of the standard sort of atrial fibrillation had started, then, spontaneously self-organized into a coordinated wave spiraling cyclically through the atria. You can see the wave in the screenshot.

This really grabbed my attention, so I watched it for a while, and discovered that, strangely enough, the wave was quite stable.

Not even the normal sinus beats, which occasionally inserted themselves in the path of the wave, were very good at disrupting it. Not long after this screenshot, it degenerated rather suddenly into normal atrial fibrillation.

Then, while having a look at the pictures a few minutes later, I realized something: my simulation had produced true atrial flutter. What I saw before and called atrial flutter was really just organized fibrillation. This, though, exhibits all the classic features of atrial flutter: rapid atrial waves with a sawtooth shape. In this case, since I had the ventricular response set to be fairly quick, it turned into quite realistic atrial tachycardia.

I tried to save the state of the simulation so that I could study it later, but as there are some features of NetLogo with which I’m not entirely familiar, I wasn’t able to do it. So, for now, I guess I’ll just keep running HeartSim in the background until I see that rhythm again.

The Trouble With Science Fiction

Over the years, I’ve been developing an aversion to modern science fiction — both literary and cinematic. So, in the true spirit of blogging, I thought I’d share some of my complaints and suggestions with the world that is the Internet. Here goes.

My chief complaint is that science fiction these days is all too frequently just about the science, never the fiction. In fact, a great deal of it reads like a lengthy, flowery technical manual, or like something written by a futurist. Nowadays, very little time is taken in character development or plot structuring. This problem plagues sci-fi movies with an especial severity. Now, many will no doubt protest that the “sci” is what sci-fi is all about, but I beg to differ. To me, it seems  that sci-fi should only ever be deployed as a tool to allow the telling of stories that aren’t possible in other genres. For example, there are few genres that can so eloquently explore the ramifications of mankind’s creations the way AI-centric sci-fi does. Interspecies tolerance — or lack thereof — speaks potently about our own tolerances and intolerances of each other, in a way that is frequently more poignant and direct than the literarily bogged-down novels of the past.

There is of course a much more serious problem with modern science fiction, and that is that it all seems to be written or filmed by a bunch of pimply adolescent technophiles with about the same amount of imagination as the average armadillo. Most science fiction novels — at least those by the “up and coming” writers — seem to be getting uncomfortably close to the gauzy rococo fantasies explored in the fantasy genre and Japnese anime (I must take a moment to warn my readers, I am terribly un-fond of anime. I think that it’s a bloated, stereotyped medium that Westernizes more sloppily than almost any other Japanese format). While I have no problem per se with either of these, I think that they tend to make the work clichéd and uninteresting. After all, how many angsty twentysomething protagonists with blue hair do we really need?

And as for the lack of imagination, if imagination were oxygen, then somewhere in the world would be a huge pile of asphyxiated sci-fi writers. About seventy-five percent of them would be screenwriters. It seems to me that there are about five science-fiction plots out there, and that whenever a young writer wants to get into the business, they simply pick one, add on some extra bits, throw in some filler, and call it a day. Now, this may indeed be the way that most novels are written — after all, there is only a finite number of plots out there, they’re bound to get re-used eventually — but the problem with that is that science fiction is a very dense pocket of literature, and any excess overlap brings it dangerously close to homogenity. What happened to the Arthur C. Clarkes, the Charles Strosses, the Isaac Asimovs, and the Phillip K. Dickses (Yes, Dickses. I am going out of my way to avoid being juvenile here, give me a break.)? What happened to the ebullient, enterprising spirit that made sci-fi great? After all, as I said before, science fiction is merely a stepladder to reach the previously-inaccessible reaches of literature. What happened to the galaxy-spanning civilizations, the beings composed of ions and magnetic fields, the self-made destructions of civilizations, and the kind of remarkable creativity of a story like Asimov’s “The Nine Billion Names of God”?

Here are my suggestions to my fellow writers of science fiction, in my standard, convenient, lazy, bulleted format:

• Don’t be afraid to step outside of humanity. What science fiction really needs right now is somebody with the talent to make readers feel connected to a character of an entirely different species. Anyone who can do that — or has done that — with any elegance can have my pocket protector.
• Don’t rely on archetypes and stereotypes. If your writing has become the standard test-of-the-hero’s-mettle stuff, then smack yourself in the face with your manuscript.
• Only use sci-fi where it is truly needed. Some stories can be told much more elegantly within the confines of a far less exotic genre. Imagine if John Steinbeck had been born a generation later, and had tried to express the beautiful themes of Of Mice and Men as a space opera. The mind recoils.
• Don’t, I repeat, don’t be a slave to the genre. Sci-fi does not necessarily need pitched space battles, homogenous gray-skinned aliens, and advanced weapons to be great. Isaac Asimov did it without aliens altogether. Arthur C. Clarke went beyond the whole “Take us to your leader” thing. And Charles Stross went — and is going — beyond the idea of humanoids as the only viable kinds of aliens. And none of the previous needed any kind of blinky, flashing lights or space battles to do what they did. I suppose what I’m trying to say is, don’t write anything that resembles any science fiction movie produced in the last thirty years.

Those are my thoughts. Enjoy.

Wherefore Universe?

Today, as I sat around idly ruminating, a question which has often troubled me bubbled back up in my mind: why does the Universe exist? What is it about the laws of physics that somehow magically cause a Universe to come into being.

I’ve thought long and hard about this problem, and the other day, I believe that I may have hit upon a possible solution. Here goes.

We think of the Universe as a fairly orderly place. Even when we deal with really peculiar theories like the Standard Model and Quantum Mechanics, the Universe is orderly. Cause and effect always, always applies. Well, not quite. Imagine a cloud of gas floating in interstellar space. Now, imagine that you have some sort of super-microscope, and you zoom in on part of the cloud. Eventually, you can see the gas molecules, and then, the individual atoms. As you zoom in yet further, the nucleus of a single atom becomes visible, then the quarks and gluons that make up the interior of a single nucleon. Keep zooming in. It’s going to take a while, even at this rate. Your ultimate goal is to reach 10^-35 meters, the so-called Planck length, which is 10^-20 times the diameter of a single proton. This is it: the bottom of the Universe. There is no meaningful distance smaller than the Planck length. I know that seems nonsensical, but bear with me.

You see, to measure the position of anything, you have to bounce something off it, whether that be a photon, an electron, a proton, whatever. In order to determine the position with greater accuracy, you have to bounce the particle — let’s assume it’s a photon for our purposes — with a higher energy. The angle at which the photon returns to you allows you to determine the position of the target particle. Well, as it turns out, there is a theoretical limit to this precision. Once you know the particle’s location down to an error of less than 10^-35 meters, such measurement requires so much energy that the measurement would produce a microscopic black hole, which would trap the bouncing photon, and prevent the information on the particle’s position from ever reaching you. So, it’s not meaningful to talk about any distance smaller than the Planck length, since nothing can interact with anything smaller than that.

The peculiarities at the Planck scale are legion. Not only can you not measure anything smaller, but space itself becomes unpredictable, twisting and warping and bubbling. Particles appear from nowhere and then swirl away into nothing. Energy is created and destroyed. And the important thing, causality does not seem to apply. Events can occur on the Planck scale without any cause in the Universe.

You might — if you were brave enough to actually read through that long, drawn-out description — be wondering what this has to do with the cause of the Universe. Well, I’m just getting to that.

You see, our current physical models of the Universe cannot actually tell us what happened before about 10^-45 seconds prior to the beginning (that number, incidentally, is the Planck time. There is no meaningful time interval shorter than the Planck time, as there is no meaningful spatial interval shorter than the Planck length). That is because, before 10^-45 seconds, the baby universe was smaller than the Planck length, which means that our traditional notions of space, time, and causality do not apply.

So, perhaps this is the answer to why the universe exists: there is no cause, or if there is, we cannot comprehend it, because causality is different or nonexistent at such tiny scales. Perhaps at such scales, where causality is so flexible, events can cause themselves. Or perhaps, even more paradoxically, effect can precede cause. So, perhaps, the origin of the Universe and the laws of physics were one and the same thing: the Universe itself.

Think about it.

Life Imitates Art: A Somewhat Twisted Look at Parasites

Everybody knows the story. It shows up in a lot of sci-fi movies: a secondary character gets attacked by some sort of creature that latches onto their head and forces them to do its nefarious bidding. Well, as it turns out, this isn’t science fiction. Such phenomena are actually observed in nature (thus the lame “life-imitates-art” reference in the title). As it turns out, there actually exist a few species of insect and virus that alter (and sometimes control) the host’s brain. As a service to those warped-minded individuals (such as myself) who find this kind of thing fascinating, I present to you, dear reader, the List of the Most Disgusting and Interesting Parasites I Could Find:

AUTHOR’s NOTE: I take no responsibility for any vomiting or nightmares resulting from reading through this list…

• Emerald Cockroach Wasp (Ampulex compressa): This nasty little insect mounts the back of a cockroach, jabs its stinger through the back of the roach’s head, and using a precise set of sensors, guides the stinger, brain-surgeon-like, into the part of the cockroach’s brain that controls the escape reflex, injecting it with a venom. The wasp then — and this is the part that really blew me away — leads the now “zombified” cockroach around by the antenna, until they reach the wasp burrow, where they, in the standard fashion, lay an egg inside the cockroach, which eventually hatches, and the cockroach gets eaten from the inside out. As usual. Credit for the article upon which this bullet point is based goes to this site.
• Hairworm (Spinochorodes tellini): This was the first of the creepy brain-parasites I learned about. This diabolical little nematode enters a grasshopper’s body, and steadily grows until it occupies nearly all of the space within the grasshopper’s exoskeleton. Then, when it’s time for the worm to escape and mate — which it can only do in the water — it forces the cricket to drown itself in a puddle, thus freeing the hairworm to frolic and breed. You can learn more here.
• Rabies: All right, this one’s not as obscure as the others, but I still find it fascinating, in a macabre sort of way. I mean, rabies is practically the perfect parasite: it induces violent behavior in those infected by it, which leads to biting and scratching, which are the perfect methods of transmission of the virus! It’s hard to get much more direct than that. I’ve always though that a form of rabies that could spread more easily (perhaps even through mere close contact) would make a great basis for a horror film.
• The Ichneumon Wasp: This wasp is the creepiest, in terms of sheer gore. The female wasp stabs her ovipositor (that’s such a cool word…an ovipositor is basically a tube that a female insect uses to insert or deposit eggs) into a caterpillar, and injects some eggs. Before long, wasp larvae hatch and eat the caterpillar from the inside out. This, too, would probably make a good horror movie.
• Lancet Fluke (Dicrocoelium dendriticum): This fluke loves mammalian livers. In order to spread to a new liver, the parasites, excreted in the host’s feces, must be eaten by a snail. Then, when an ant drinks moisture from the snail’s trial (why it would do this is beyond me; snail slime is nasty), it becomes infected with juvenile flukes. These spread into the tiny little bundle of neurons the ant calls a brain (all right, it’s actually called a “ganglion” if you want to be specific). There, they lie in wait, controlling the host ant’s actions until nightfall, when they force the ant to climb a blade of grass, and latch on, waiting to be eaten by a liver-bearing herbivore. Creepy. Thanks to Carl Zimmer’s article The Return of the Puppet Masters for information about this one.
• Toxoplasma gondii: This nasty little parasite lives in cats, and spreads from cat to cat mainly via rats and other small mammals. The creepy thing is that, although otherwise normal-seeming, T. gondii-infected rats are completely unafraid of the smell of cats, a scent which normally terrifies them. Kind of makes you wonder: who among us might at this very moment be under the influence of…the parasites. Heh…silly idea…the parasites are our friends…the parasites want to help us…Hm…I don’t know what compelled me to write that… Credit for pretty much all of this bullet point also goes to Carl Zimmer.

I’ll amend this list if I run across any other interesting additions.

Memorizing the Periodic Table

Partly out of boredom, and partly out of irritation at never, ever knowing the atomic weight of a particular element, I have decided to embark on the journey to memorize the entire periodic table (well, all the elements up to and including Uranium, at least). But what would even give me such a peculiar idea? Well, blame Oliver Sacks. I was reading through his book The Man Who Mistook His Wife For a Hat (excellent book, by the way, for those who haven’t read it), and I was particularly intrigued by his discussion when talking about numerical savants’ familiarity with numbers: Dmitri Mendeleev, the developer of the periodic table, carried around a deck of cars with the elements’ properties listed on them, and looked them over until he knew them by heart. I’ve always wanted to learn something this thoroughly (and, in fact, I had a set of cars like this myself when I was younger). So, there you have it. I’ll keep my reader(s?) abreast of my progress.

A Debate

 Author’s Note: These are my personal (and sometimes inaccurate) ruminations on the idea of a simulated universe. I don’t claim to know anything about the philosophical treatment this idea has already been given, nor do I know much about any of the arguments. If I’ve stolen someone’s idea, I apologize…I didn’t do it intentionally.

Bob sat on the great stone platform atop the mountain, gazing down over the endless convolutions of the Great Valleys below him. His face bore a look of the most intense concentration. His brow was furrowed, and his eyes were distant and contemplative. It was in this state that Alice found him. She ascended the great staircase and seated herself next to him.

“So there you are.”

“Yes.” It was nothing more than a pleasantry, for Bob was far too lost in thought for any real communication.

“What on Earth could you be thinking about with such intensity?” Bob did not answer, but instead maintained his tense posture for another minute or so, then relaxed, and looked up at Alice.

“I’m sorry, what did you ask?”

“What are you thinking about with such intensity?”

“Oh, well…I’ve just been considering something.”

“Well, what?” A look passed across Bob’s face, and Alice realized with concern that he could very easily lapse back into mute contemplation.

“I’ve just been wondering…it seems to me that we are living in a simulated world?”

“What? What do you mean by that?”

“I simply mean that the Universe that we see is really just an assemblage of data in a computer somewhere, and that the physical laws we observe – and their consequences, such as our own sentience – are simply processes within that computer. You know, program instructions.” Alice rolled her eyes surreptitiously, then crossed her arms.

“Not this subject again!”

“Well, I believe it deserves consideration!”

“Why? It’s an entirely foolish idea!”

“Why’s that?”

“Well, how could we possibly find ourselves in a computerized Universe? No computer could ever manage such a feat of simulation, and even if it could, it wouldn’t be able to produce the robust world we observe!”

“That’s where you’re wrong, I believe.” Bob had now turned fully towards her, and had fixed her with the challenging gaze that was his trademark.

“Oh, really? And have you any evidence of my wrongness?”

“Of course. You know – you should know better than anyone else – that I never make a claim without having a good argument to support it.”

“Well?”

“Okay. Since I am going to base my argument on the idea that a computer likely simulates the universe we live in, I’ll make my argument from a computer-based standpoint, even though essentially any suitable substrate could simulate our Universe. Now, consider a simple electronic circuit.”

“All right.”

“Right. This circuit consists of a small mathematical processor, a few registers for storing data, and all the other necessary equipment for a circuit to work properly.”

“I’m with you so far.”

“Now, say this circuit, on every tick of its internal clock, performed the following calculation: take the value stored in the data registers – call it x – and squared it, then multiplied it by some constant k, then subtracted from the result the value j times x, j being another constant, then stored all of that back in the data registers, and repeated the process ad infinitum.”

“I don’t quite see your point here, Bob. I must confess that I’m rather confused.”

“That is because you’re not thinking about things correctly. Okay, I’ll give you a hint. What would a system such as the one I’ve described represent?”

“Some mathematical function, I think.”

“Go up one more level of abstraction.”

“What do you mean? There are no other levels of abstraction in this system. Either it is a system consisting of electrons darting from atom to atom in a silicon circuit, or it is an abstract mathematical system. There is nothing else!”

“Ah, but you’re wrong on that account! For, think about physical laws!”

“What about physical laws?”

“Are they not just a higher level of abstraction than pure mathematics?”

“Hm…no, I don’t believe they are.”

“I think our definitions of ‘abstraction’ may differ. For now, I’m defining ‘abstraction’ to mean ‘representation,’ or something to that effect.”

“Ah, I see. Well, given that definition, I suppose I’d have to agree: physical laws could be seen as a third level of abstraction.”

“Right. Now, back to my imaginary circuit. Think about what its third level of abstraction would be.”

Alice thought for a moment, and then her face lit up.

“Aha! It seems to be the equations of motion for an accelerating projectile subject to air resistance!”

“Very good!”

“But what was the point of the whole exercise?”
“Be patient! I was coming to that! Now, couldn’t one argue – rather convincingly – that in many ways, the creation of this circuit has also brought into existence an accelerating projectile subject to air resistance?”

“No, I don’t think so. The projectile is not real, it’s merely an abstract representation, created by us, its conscious observers.”

“I’ll ignore your little play on the definition of ‘abstraction’ there, for the moment. So, you say that the circuit’s ‘higher-level’ meaning as an accelerating projectile exists only in the minds of us, its conscious observers?”

“Yes, that’s what I said.”

“Well, you’ve stumbled right into my philosophical trap, then! For, is not the mind itself little more than a circuit, similar to (but, of course, infinitely more complicated than) the circuit we are discussing?” Alice looked blindsided for a moment, then recovered.

“The mind is something different. Your little circuit is fixed in time. It cannot observe itself nor rewire itself. The brain can.”

“Ah, yes, but, still, on the cellular level, is not the brain only a ’system of electrons darting from atom to atom in a biological circuit’, as you said before?” Alice looked as though she had been physically struck.

“Oh, dear…I believe that’s checkmate…Hm…”

“Yes, you see? There can exist such abstractions, the mind being the primary one!” Alice knitted her brow while her toe fidgeted with a pebble.

“Okay, I concede that such abstractions are possible in our Universe. But since our observation is necessary to bring these abstractions – such as the one of the projectile in your nice little argument a moment ago – to light.”

“Ah, I was hoping you’d try to wiggle free in that way, for I have the perfect rebuttal!”

“And what’s that?”

“Imagine a computer, a huge computer. As big as the Earth, if you like, or bigger. It has memory cells for the storage of data, and processors for the computation of the effects of physical laws. Now, furthermore, let’s say that this computer is running a program that simulates the interaction of a huge number of elementary particles, based on physical laws that are the same as those in this Universe.”

“All right, I follow you so far.”

“Right. Now, let’s further suppose that this computer was allowed to run long enough that the Computed Universe experienced the Big Bang, the formation of ‘normal’ matter, the coalescence of stars and galaxies, and the formation of planets, and all the requisite molecules of life. And then, let’s assume that life does indeed begin in this Computed Universe, and that it evolves to the point where it has developed something like a complex nervous system – what resemblance it actually bears to a nervous system is immaterial, it just must fulfill a very similar function. Then, through the slings and arrows of Darwinian evolution – you don’t disagree that Darwinian evolution would necessarily take place, do you?” Alice shook her head. She knew that evolution was a principle based merely on the idea that the more fit an organism is for its environment, the more likely it will be to be represented in the next generation, and this principle is completely ignorant of the material composition of what is actually evolving. “Good. Then, we have Darwinian evolution, and let’s assume that it produces self-aware organisms. Now, do we not have that ’secret ingredient’ necessary to allow the universe to be viewed in an abstract way?” Alice was at a loss for words, and she had to work to keep her mouth from falling agape.”

“Oh dear…I seem to have argued myself into a corner…if I allow for the existence of conscious minds, then it seems that I must inevitably fall to your argument…” Bob looked rather satisfied with himself, but then Alice took on a very resolute expression. “Wait! Would not this giant computer still require the observation of its operators in order to see the abstract things – the conscious observers – that it represents?” Bob smiled knowingly, and Alice realized that he would soon deliver his finishing blow.

“No more than our Universe requires a godlike figure to observe it in order for ourselves to exist.” Alice nearly fell off the rock. Then, she steadied herself, and a smile crossed her lips.

“Ah, but you have forgotten your original claim! How can you claim that we live in a simulated Universe? All you have done is to prove that it is possible that we might be, not that it is inevitable, or even likely!” It was Bob’s turn to grin.

“I was waiting for you to recover, so that I could philosophically knock you down once more.” Alice feigned offense.

“Oh, you philosophical sadist!” They both had a good laugh, then Bob suddenly grew serious.

“Now, for the final blow!”

“I’m ready.”

“Let’s assume that some species in some Universe – simulated or not – created a computer simulation of a Universe. Suppose furthermore that that simulation was rich enough that observers – conscious entities – could arise within it. Then suppose that these Computed Observers created their own Computed Universes – for it seems inevitable that any such Universe-Computing race would compute more than one Universe – and within these Computed Computed Universes, Thrice-Computed Universes arose. This would continue until the ‘Nth-Time-Computed Universes’ became too small – for any Computed Universe must necessarily be smaller than the Universe in which it is computed – for conscious observers to arise. Despite this limitation, is it not obvious that there would be an immense hierarchy of simulated Universes for every ‘real’ Universe?” Alice nodded gravely, her defeat seeming imminent. “So, given the laws of probability, since there is such a hugely larger number of Computed Universes, compared to the original few ‘real’ ones, isn’t it much more likely that we find ourselves in a Computed Universe.” Alice sighed loudly, but then a glimmer of hope touched her countenance. After a few moments’ introspection, she smiled.

“Unless, of course, some of the current findings of cosmology prove true, and there is an infinite number of ‘real’ Universes!”

“I don’t follow.”

“Well, consider it! If there is an infinite number of ’starter’ Universes – that is, ones that are not simulated – there would then be an infinity of Computed Universes, too, but only an infinity, since the mathematical laws of infinite numbers are so slippery. Then, the probability that we find ourselves in a Computed Universe is only one-half, since there is an equal number of both.” Bob looked flabbergasted.

“Oh, dear! I hadn’t even considered that! Excellent riposte, Alice!”

“Thank you!”

“But, wait! Suppose that instead of a finite hierarchy of Computed Universes, the hierarchy was infinite!”

“How would that even be possible.”

“Well, suppose that the infinite ’starter set’ of Universes was itself simulated, and the Universe in which they were simulated was also simulated, and so on out to infinity!” Alice laughed. It was now her turn to be sadistic.

“But, Cantor showed that an infinity is an infinity. Even if an infinity of initial universes produced an infinity of simulated ones, their numbers would still be equal!” Bob seemed almost to deflate.

“Well, one could get around that by supposing that there is only a single Universe.”

“Not really.” Alice was now philosophizing at full steam, ready to make the kill. “Since, in an infinite Universe – which ours appears to be, based on telescopic observations – there will be regions too far apart to communicate, which are separated by the insurmountability of the speed of light, so that no information can ever pass between them. These regions might as well be separate Universes. This position would only be strengthened if the physical laws could vary from one such region to the next. No matter what you do, unless the Universe is closed and finite – which seems unlikely given the data – then we only have a fifty-percent chance of finding ourselves in a Computed Universe after all!”

Bob was silent for a long time, his head bowed. Then, he began to emit a peculiar rhythmic sound, a little repetitive squeaking. Concerned that he might actually be weeping, Alice leaned in to comfort him, but then the squeaking erupted into chuckling, then into uproarious laughter. Alice was confused.

“What’s so amusing?” Bob stopped laughing, shot her an impish grin, and extended his hand. In his palm was a coin. Alice joined in his laughter, and said, “If it comes up heads, we’re living in a real Universe…otherwise…”

…

Windows of Lucidity, Again

In a previous post, I pondered what caused some people suffering from degenerative brain diseases (such as Alzheimer’s and Creutzfeldt-Jakob disease) to suddenly, for short periods of time, regain their lost faculties, and even their ravaged short-term memories. Well now, having read Norman Doidge’s excellent book The Brain that Changes Itself, I believe that I may have an answer.

Doidge’s book discusses the rapidly-growing field of neuroplasticity, the study of how the brain can “re-wire” itself. It’s been shown that stroke patients who are left with minimal muscle control on one side of their body can, over time, re-train their brains, through long and arduous practice, to use that side again. After long hours of daily training, they begin to recover use of their affected limbs. That’s neuroplasticity at work.

Therefore, couldn’t this idea also be applied to the kind of brain damage that results from, say, Alzheimer’s? Over time, as the brain attempts to work around the damage caused by the disease, might it not discover a “hidden pathway” that allows it to function normally, if only for a while? It certainly seems possible. This might also go some way to explain why windows of lucidity are so painfully transient: the damage accumulating from the disease process rapidly wipes out these newfound pathways.

Just food for thought.

Primordial Life

I was reading my latest Scientific American. I started off with a cover story, an article about a new theory on the origin of life. And for once in my life, I actually had something to add to their theory.

 Here’s the jist of the article: whereas, in the past, most theories about the origin of life had been based on the idea of the spontaneous generation of RNA (ribonucleic acid), which has the curious property of being able to copy itself under the right cirumstances, but is hugely unlikely to arise at random, the writers of the article propose that life actually may have begun as simple self-sustaining chemical reactions. For example, suppose that one of these primitive organisms consisted of chemicals A, B, and C. The organism takes X from the environment, and in a reaction, converts X to Y, releasing energy, and re-creating the initial reactants (this time in greater number). Such a chemical organism would be able to utilize energy and reproduce in the traditional sense, and does not require the highly unlikely spontaneous generation of RNA.

Later, while I was thinking about the concepts in the article, I began to wonder what might happen if two of these primitive metabolic organisms were to merge by accident. If there was any chance coupling of some of the reactions taking place in the individual organisms, there might be some benefit to be had in their union. Thus, the evolution of such organisms could take place at a very fast pace, and such unions might also help explain how metabolic reactions became so complex.

 I know you’re tired of hearing it, but I’m going to say it anyway: just food for thought…

Unreality

I read an argument some years ago explaining why it is highly likely that we human beings are living in a computer simulation. It was quite elegant, and I felt compelled to share it here. It goes something like this:

If it is possible to create a simulation of a universe with sufficient complexity to eventually contain conscious observers, then  it is highly likely that other such simulations will be built in the original universe. Even if they are not, simulations will be built within the simulated universe. Then, the original universe applies recursively to each level of simulation, until a level is reached where the simulation cannot be complex enough to contain conscious observers (this is inevitable, since any simulated universe must be less complex than the universe in which it is simulated: if you assigned one bit to each particle in the universe, the simulated universe would still only be as large as the original universe itself, setting an upper bound on its size). Still, provided a single initial starting universe, the number of simulated universes will far outnumber that of real ones, so the probability is highest that we, as conscious observers, exist in such a simulation. (Think about somebody dropped into a random universe. Which universe would they most likely find themselves in?)

There are, however, a few cases where this argument does not hold.

1. If it is not possible for a universe to be simulated in a manner complex enough to allow for conscious observers to develop within it.
2. Nobody ever builds a simulation in the first place.
3. We are living in a multiverse. If there is more than one universe, then most theories hold that there will be an infinite number. Since an infinite number of simulated universes is possible in such a situation, but there is also an infinite number of universes, the maximum probability that we are living in a simulation should be (should, but I’m not great with transfinite mathematics) fifty percent.

Think about it.

Superstar: VY Canis Majoris

Now, usually in this little blog, I prefer to report the most current scientific news I can find. But I have discovered something that so shocked me that I had to talk about it, old news as it may be.

While I was wandering about on the internet, I ran across a computer-generated video that lined up all of the larger bodies in the solar system, starting from Pluto. It panned and zoomed across the line, progressing to Earth, then to Saturn, Jupiter, the sun, and so on. I was thunderstruck by the tiny scale of the sun compared to the giant star Antares. But what really knocked my socks off was the grandeur of the star VV Cephei, which was so large that the low resolution of the video actually made the sun invisible when the camera was zoomed out far enough to see all of the star. A quick consultation with Wikipedia revealed that VV Cephei, while enormous, is not actually the largest star. The red hypergiant VY Canis Majoris is actually a full ten percent larger than that!

Always having been a fan of scale comparisons, I brought up Blender immediately (Blender is by far the coolest piece of free software I’ve ever seen. It’s an open-source 3D modeling and rendering engine, and it rivals or beats anything else I’ve seen on the market. You can learn more here, if you feel so inclined.) I’ve found Blender very handy for this, since you can enter an exact numerical scaling factor when resizing an object. So I created a sphere to represent the Sun, and a sphere to represent VY Canis Majoris (which is 2100 times larger). This was the result:

Click here for a larger version of this image.

The Sun is that little yellow blotch. The enormous red one is VY Canis Majoris. The sun compared to this giant among stars is, to me, like the height of Mount Everest compared to the Earth on which it sits.

Once in a blue moon, the universe still amazes me…

The House Comes Through

The other day, I was, as usual, listening to NPR, and somebody mentioned something off-hand that caught my attention. This February, a committee of the United States House of Representatives approved a bill that would ban any kind of discrimination based on genetics. This, to me, is a step in the right direction, and sets back what looked like a truly terrible misuse of science.

Here’s the problem: with genetic screening for common diseases such as diabetes, multiple sclerosis, Alzheimer’s, and cystic fibrosis becoming cheaper, more accurate, and more widespread, the insurance companies are faced with a veritable gold mine: they can insure only people who are at little or no risk of getting any of these diseases, so that less of “their” profits go towards treating people. This is clearly an ethical dilemma. Just because these people are stricken with diseases doesn’t mean they don’t have a right to medical care, and the right to live the most normal lives they can. Many have argued that something must be done about the steadily increasing possibility of such discrimination.

Enter the United States government. I never thought I’d be able to use that phrase: back when the Republicans controlled the Congress, they never passed the bills I wanted to see passed, and ever since the Democrats took over, it doesn’t seem they’ve passed much of anything. Well, assuming this bill passes, they’re coming through at last! Of course, given the Congress’s tendency to obsess about a few high-profile issues to the exclusion of all others, my hope may be premature…

Political Sum-Over-Histories (and a solemn note on the Virginia Tech shootings)

Note: Being a reasonably decent human being, I feel I would be terribly remiss if I did not give my heartfelt condolences to the faculty and staff of Virginia Tech, following yesterday’s terrifying shooting. As a member of the college-going population, I myself was absolutely horrified that such a thing is even possible. As for the killer, who may have fancied that he would render the authorities powerless by killing himself before they could, I say they drag his rotten corpse behind a dump truck for a while. Now, please don’t fault me on this, dear readers, but I feel that the best course of action for me would be to simply go on as normal, as nothing I can do will change the facts.

Green and Dopamine: The Money-Pleasure Connection

A few months ago, I was reading Read Montague’s Why Choose This Book (about how human beings make decisions, and not a bad read, as far as popular neuroscience goes), and I cam to quite a fascinating realization: People like money because money foreshadows pleasure.  I’ll try to keep things as straightforward as possible, but here goes:

In the brain, pleasure, reward, and the significance of events are all linked to levels of dopamine, which is one of the brain’s chemical transmitters. Dopamine levels increase in order to “cement” memories of pleasurable things, which is why we seek out such things so actively. Dopamine is also used, however, to predict pleasurable stimuli. For example, say you take a dog, and ring a bell. You then present it with food, or some other form of treat. Repeat this many times. After a while, the pleasure sensations that the dog got from the treat will be transferred to the event of hearing the bell. In other words, an event that reliably predicts reward will become a reward.  And if you insert another event in there, say, flashing a red light, then the pleasure will be transferred to the new stimulus, and so on.

And that brings us back to money. From an early age, humans learn that every time they spend money, they will get something they desire. The pleasure of getting that thing is then transferred to the spending of money. Then, this pleasure response is transferred to getting money. Which is, in my mind, anyway, a fairly good explanation of why people are so damned greedy and possessive with money. It might also explain things like compulsive gambling and compulsive shopping: the pleasure signal gets linked to going to the casino or the mall, and human beings have a reliable habit of seeking out pleasure.

And, to extend this idea further, consider addiction. When someone consumes an addicting drug, dopamine levels rise (cocaine is especially bad in this regard, since it directly raises dopamine levels, by keeping the body from re-absorbing it and recycling it). After a while, as in the dog example or the money example above, the pleasure of the drug itself is transferred to buying the drug, getting the drug, et cetera. And from this, it can be fairly reasonably assumed that compulsive gambling and other such compulsive behaviors are true addictions, a concept which has been in doubt in the past.

Just more food for thought…

(PS: Thanks to Read Montague; some of his book was tedious, but if nothing else, the money-dopamine connection was enlightening)

Fermilab Makes a Comeback

As usual, Reality does its absolute best to make me look like a complete fool. Just a few days after I wrote my post after the coming obsolescence of Fermilab, it seems they’ve managed to pull off one last great find.

Some people know that there are six varieties of quark (two of these varieties make up the particles we’re used to, except the electron, which is actually a lepton, I think). We’ve managed to observe five of them conclusively, but the rather heavyset top quark has a particle-accelerator signature which looks similar to that of some other collision traces. Well, the folks at Fermilab think they’ve finally figured out how to conclusively produce one.

By exploiting the weak-force interactions between electrons and positrons (I think that’s what they were), the Fermilabians managed to create something that they’re fairly certain is a top quark. This brings us one step closer to the Higgs Particle, which is theorized to be the reason all particles have mass (that may be why they call it the God Particle, although when I think of godlike powers, conferring inertia is not exactly at the top of the list). Well, Fermilab, I wish you luck! They just might be able to beat CERN to this one.

Side Note: I don’t know why more young people don’t get interested in physics, especially particle physics. “Hey kids, why don’t you come work at our particle accelerator. You get to smash things together really hard, and get paid for it!”

Fermilab? That Old Piece of Junk?

It seems that the old particle accelerator at Fermilab is soon to be outdone again. After being surpassed by the Large Hadron Collider (which is supposed to come online late this year, I think), the dowdy old American accelerator will now be in competition with the International Linear Collider. Of course, poor old Fermilab may get lucky: it’s been chosen as one of the potential sites for the construction of the new machine. Actually, I’ve always been partial to CERN, which may or may not be one of the potential sites.

Well, since I’m on the subject of the LHC and CERN, I must express a bit of a concern I’ve been harboring ever since I heard about the LHC. First, some background is needed: the LHC is a segment of the CERN particle accelerator which is (CERN hopes) to be the most powerful particle collider on Earth. Powerful enough, in fact, that the designers expect that it will create a subatomic black hole. Therein lies my concern: I am perfectly aware that black holes evaporate and disappear by emitting Hawking radiation until they’re gone, but I would certainly hope that it will evaporate quickly. You see, if the little black hole lasts long enough, it could begin consuming particles in the chamber, drift out of the chamber, and begin consuming surface material. This would happen fairly quickly, and the gravitational effects would increase exponentially until most or all of the planet had ben consumed. So I certainly hope that they’ve calculated the evaporation time quite precisely. I also hope they finally learn something about the veracity of string theory.

Peculiar Spacetime Manifolds

Though I haven’t reached a point in my tensor-analysis self-study where I can describe them mathematically, unusual spacetime geometries and topologies have always fascinated me, and it’s always kind of annoyed me that they don’t get more mathematical press. No matter how improbable they might be, and now matter how insoluble the equations are, I’d really like to read a study of these odd spaces.

For example, what about a toroidal spacetime manifold? This is the only nonstandard spacetime that ever gets discussed. From what I’ve read, an observer in such a universe would see an “extra” image of whatever they could see at a distance (call it M), and another extra image at a distance of aM (where a is the ratio of the “tube” radius to the “toroidal” radius). The set of closed geodesics would be infinite in such a universe.

Or, what about some sort of fractal spactime? For example, begin with a “spherical” spacetime, and join up six more spherical spacetimes (smoothing the junctions, to avoid discontinuities), and then add four such spacetimes to each exterior sphere in the same way, ad infinitum. There would be infinite geodesics in the spacetime, even if the geodesic does not have both ends at infinity.

Or, consider an infinitely long “cylindrical” spacetime. There would be an infinite set of closed geodesics, but also an infinite number of open ones.

And finally, the mother of them all: non-orientable spacetimes! What about a Klein spacetime? Geometrically similar to the toroidal spacetime, but with some reversals along the way. Or a Möbius spacetime? Or one based on the projective plane? The possibilities are enormous!

A Theory of Theories

The other day, I was having a conversation with a friend of mine, and I got thinking about scientific theories. I was maily considering the purported “theories of everything” (string theory, loop quantum gravity, twistor theory, etc.), and I began to wonder: has anyone developed or attempted to develop a “theory of theories of everything”? Would such an enterprise be fruitful or a waste of time?

Well, from this station, my train of thought kind of lost its brakes and went speeding down the hill…and I got wondering yet again: is it possible that no such theory of everything exists? Is it possible that humans will get caught in an unending series of revisions, each theory matching nature more and more closely, but each theory still having its own flaws and inaccuracies. But what about the multiverse? Even if there is no “theory of everything” in our universe, might there not be one in a different universe? What this question boils down to is this: Is it possible that the underlying mathematical and theoretical structure of a particular bit of the multiverse universal, or is it local? Might mathematics be more or less consistent (removing or worsening things like Russell’s paradox and Gödel’s incompleteness problem) in other universes?

Just some more food for thought…

Windows of Lucidity

In some patients afflited with Alzheimer’s Disease, Creutzfeldt-Jakob Disease, age-related dementia, and some other neurodegenerative diseases, the patients, after having lost a significant amount of their memory and cognitive abilities, will “snap out of it” for brief periods, and temporarily regain some (or in rare cases, all) of their mental function. I’ve always wondered why this happens, but after reading the account of the man who was in a coma for 19 years, and then came out of it, I think I have some idea where these windows of lucidity come from.

I think, perhaps, that since memories and functions are stored “holographically” (that is, in a distributed fasion throughout the brain), and since the brain’s functions are remarkably plastic, that as the neurodegenerative disease progresses, the patient’s brain attempts to work around the spots damaged by the disease (much as it did in the 19-year coma patient who woke up and regained a great deal of function), and connnect to the areas that are still reasonably functional.

Just food for thought…