Thursday, January 22, 2009

More on the Fundamental Status of Time

Here are two more links to arguments for why time is fundamental:

A very good talk by Lee Smolin at a Perimeter Institute conference last fall. I thought he did a very good job in explaining how physics got into the practice of viewing time in a geometric fashion (with no important role for the present moment) and why this will not work when formulating a theory of the universe as a whole.

Here's George Ellis in another entry from the FQXi essay contest explaining why it is a mistake to try to describe the universe without time asymmetry.

35 comments:

Allen said...

Hypothetical situation. All of the particles in the universe kick into reverse and start going backwards. For some reason every particle in the universe instantaneously reverses course. And also space begins contracting instead of expanding. Everything in the universe hits a rubberwall and bounces back 180 degrees.

So now instead of expanding, everything is on an exact "rewind" mode, and we're headed back to the "Big Bang".

The laws of physics work the same in both directions...if you solve them forward in time, you can take your answers, reverse the equations and get your starting values, right?

This is what they always go on about with the "arrow of time". The laws of physics work the same forwards and backwards in time. It's not impossible for an egg to "unscramble", it's just very very very very very unlikely. But if it did so, no laws of physics would be broken. And, in fact, if you wait long enough, it will eventually happen.

Okay, so everything has reversed direction. The actual reversal process is, of course, impossible. But after everything reverses, everything just plays out by the normal laws of physics. Only that one instant of reversal breaks the laws of physics.

TIME is still moving forward in the same direction as before. We didn't reverse time. We just reversed the direction of every particle.

So, now photons and neutrinos no longer shoot away from the sun - instead now they shoot towards the sun, which when the photons and the neutrinos and gamma rays hit helium atoms, the helium atoms split back into individual hydrogen atoms, and absorb some energy in the process. Again, no physical laws are broken, and time is moving forward.

Now, back on earth, everything is playing out in reverse as well. You breath in carbon dioxide and absorb heat from your surroundings and use the heat to break the carbon dioxide into carbon and oxygen. You exhale the oxygen, and you turn the carbon into sugars, which you eventually return to your digestive track where it's reconstituted into food, which you regurgitate onto your fork and place it back onto your plate.

Okay. So, still no physical laws broken. Entropy is decreasing, but that's not impossible, no laws of physics are being broken.

In this case, it must happen because we perfectly reversed the trajectory of every particle in the universe.

NOW. Your brain is also working backwards. But exactly backwards from before. Every thought that you had yesterday, you will have again tomorrow, in reverse. You will unthink it.

My question is, what would you experience in this case? What would it be like to live in this universe where time is still going forward, but where all particles are retracing their steps precisely?

The laws of phsyics are still working exactly as before, but because all particle trajectories were perfectly reversed, everything is rolling back towards the big bang.

In my opinion, we wouldn't notice any difference. We would NOT experience the universe moving in reverse, we would still experience it moving forward exactly as we do now...we would still see the universe as expanding even though it was contracting, we would still see the sun giving off light and energy even though it was absorbing both. In other words, we would still see a universe with increasing entropy even though we actually would live in a universe with decreasing entropy.

And why would that be the case? Because our mental states determine what is the past for us and what is the future. There is no "external arrow of time". The arrow of time is internal. The past is the past because we remember it and because the neurons of our brains tell us that it has already happened to us. The future is the future because it's unknown, and because the neurons of our brains tell us that it will happen to us soon.

If there is an external arrow of time, it is irrelevant, because as this thought experiment shows, it doesn't affect the way we perceive time. Our internal mental state at any given instant determines what is the future and what is the past for us.

In fact, you could run the universe forwards and backwards as many times as you wanted like this. We would never notice anything. We would always percieve increasing entropy. For us, time would always move forward, never backwards.

My point being, as always, that our experience of reality is always entirely dependent on our brain state. We can't know ANYTHING about the universe that is not represented in the information of our brain state at any given instant.

Forwards or backwards, it's all just particles moving around, assuming various configurations, some of which give rise to consciousness.

Right?

Steve said...

Right.

I don't agree with some of the details of how you characterize things here, but I agree with the bottom line. The flow of time is not a function of the movement of particles in space-time. I argue that it and our experience of it are grounded at a more fundamental level, while our current notions of space-time and matter/energy are emergent concepts.

Thanks for the comment and for making my brain do some work.

Allen said...

On the subject of what is "fundamental", it seems to me that any theory of reality has to have something fundamental at the foundation that is taken as a given.

With materialism, the foundation is energy, or maybe spacetime, or quantum fields, or some combination of all three. But unless you just accept the existance of these things as fundamental brute facts, the next question is obviously "What is energy?", or "Where did spacetime come from?", or "why does it work that way?". Even if you introduce a more basic concept (e.g., strings, or spin networks, or whatever), then you can ask the exact same questions about that new fundamental concept.

With a religious view, you say that some supreme being or supernatural force is at the foundation of reality. But this introduces the question of "What is God?" or "Where did God come from?" or "What is God's motivation?"

In my view, the best candidate for the fundamental core of reality is: information. With the extra assumption (which is well grounded I think) that certain types of information have conscious first person subjective experience (something similar to Chalmers' "double aspect theory of information", http://consc.net/papers/facing.html).

The idea that information exists independently of any physical substrate, and without needing a source, (as in Modal or Platonic Realism) is I think not too big a stretch. And once you take this as your fundamental basis of reality, there really are no other questions. Everything else follows.

This does lead one to conclude that most conscious observers see chaotic and nonsensical realities, because most possible information patterns are random-ish and chaotic. BUT, so be it. We have examples of such conscious observers right here in every day life. People with schizophrenia, dementia, hallucinations, etc. All of these conditions are caused by disruptions in the information represented by the brain. Which is why I think that even starting with the assumption of physicalism, you're still lead back to idealism.

And of course, you have experience of nonsensical realities yourself, when you dream. I would say the worlds we encounter in our dreams are just as real (or unreal) as the world we see when we are awake, BUT we don't spend much time there, and when we wake our memories of the dream worlds fade and lose intensity. So we give them subordinate status.

So, to summarize, I would say that every possible conscious observer exists in a reality of their own perceptions. And every perceivable reality (both hellish and heavenly) IS perceived by every observer capable of perceiving it. And the reason for this is that the information for these perceptions exists in a platonic sense.

Allen said...

BTW, your blog is great! It's my favorite philosophy related blog.

Steve said...

Thanks very much. I'll follow up with some thoughts on your last comment (probably tomorrow).

Steve said...

Interesting thoughts. There are some things I agree with, and I have some differences.

“In my view, the best candidate for the fundamental core of reality is: information. With the extra assumption…that certain types of information have conscious first person subjective experience…”

I’m attracted by the idea of information as fundamental, but in your second sentence quoted above you put your finger on what’s missing. Information, the way we usually think of it, is static and third-person (whenever I hear the word, I think: “information for whom?”).

Rather than say some information has experience, I want to say the fundamental notion is an experiential event or interaction. There is a sense in which information is part of this picture (you can characterize an interaction as an information exchange), but there is an active element to it. And all events are experiential, not just some. It’s just that you don’t get the human style of experience unless the right kind of composite system is formed.

Concrete reality is formed by experiential interaction, so you’re right I think that each observer is at the center of his or her own reality. On the other hand, each time we interact with another observer-system, our “realities” join up into a common causal network.

In my view, the platonic/modal realist dimension comes in if you consider that each actual event is an actualization of a possibility. The possibilities exist in a non-concrete, or platonic sense.

[as an aside I just recalled that one of the early posts on this blog was about information]

Allen said...

It seems to me that you are trying to explain the fact that you consciously perceive the universe, in terms of the things that you perceive in this universe. Which is sort of circular, I think.

Let's say that you were in a long dream, and you were trying to explain the fact that you consciously perceive your dream universe, but only in terms of the things that you perceived in your dream universe. In other words, you would be trying to generate an explanation for your dream consciousness within the framework of your dream "reality". Would you expect to be successful?

I'm not certain that examining the laws of physics as they exist (or at least as we perceive them to exist) in this universe can shed any light on the issue of consciousness.

For example, let's assume for the sake of argument that it is possible for a computer simulation of a human brain to be conscious. Also we set up a simulated world to generate sensory inputs for our simulated brain. If our computer simulation is accurate in it's simulation of the laws of physics, then it will not be possible for the simulated person to determine by means of any experiment whether the reality that he perceives is real or not.

Computer software is basically just a set of logical instructions that do not depend on any particular physical hardware implementation. Any universe operating under any set of physical laws (however bizarre) that allow computation (e.g., allow systems that reliably map a given set of inputs to a given set of outputs so as to instantiate the equivalent of boolean logic gates) should be able to host computers that could run our simulation of a human consciousness and his surrounding environment.

Did you know that you can implement boolean logic gates with dominos? Cooooooool.

So, anyway, my point is that you could exist in a simulation that is running on an alien computer in an alternate universe where the laws of nature are completely different than the laws we perceive in this universe. Therefore, in that case, understanding the laws of this universe would not necessarily get you any closer to understanding why you are conscious. At best, understanding the laws of this universe would allow you to understand/explain the mechanistic aspects of human ability (the "easy" problems of consciousness, as Chalmers would say).

Allen said...

Responding more directly to your post:

As for the question of "information for whom?", I would say that some forms (patterns? instances?) of static information are capable of FIRST person interpretation. The information interprets itself, and this self-interpretation is conscious experience. An example of this type of information is the information represented by the relationships between the molecules of your brain at any given instant.

As for "information is part of this picture but there is an active element to it", it depends on your definition of "active".

I agree that experience and consciousness requires change (information is, after all, sometimes defined as "a difference that makes a difference"), but I don't agree that it must be change with respect to "time". The best analogy that I have heard is that if you have a non-horizontal line, it's Y value changes with respect to the X axis. So there is change, but not with respect to time.

If you were a 2-dimensional being, it seems plausible to me that you might experience the X axis in the above example as "time". Life to you would then just be a series of changes in Y.

Allen said...

BTW, I did watch the Lee Smolin video, and read the George Ellis paper, but I didn't find either convincing...which doesn't really mean much since I'm not a physicist.

BUT, still, I like this section from Brian Greene's Fabric of the Cosmos:


"Just as we envision all of space as really being out there, as really existing, we should also envision all of time as really being out there, as really existing too. As Einstein once said: 'For we convinced physicists, the distinction between past, present, and future is only an illusion, however persistent.' The only thing that's real is the whole of spacetime.

In this way of thinking, events, regardless of when they happen from any particular perspective, just are. They all exist. They eternally occupy their particular point in spacetime. This is no flow. If you were having a great time at the stroke of midnight on New Year's Eve, 1999, you still are, since that is just one immutable location in spacetime.

The flowing sensation from one moment to the next arises from our conscious recognition of change in our thoughts, feelings, and perceptions. Each moment in spacetime - each time slice - is like one of the still frames in a film. It exists whether or not some projector light illuminates it. To the you who is in any such moment, it is the now, it is the moment you experience at that moment. And it always will be. Moreover, within each individual slice, your thoughts and memories are sufficiently rich to yield a sense that time has continuously flowed to that moment. This feeling, this sensation that time is flowing, doesn't require previous moments - previous frames - to be sequentially illuminated."

Steve said...

Some thoughts in response.

1. On circularity: I’m proposing a monistic system -- so all interactions have the same character -- but I don’t think it is circular. I want to explain human experience by appealing the fact that the entire concrete world is ultimately composed of experiential units (events). I would note that each experience incorporates something novel (which is drawn from the space of possibilities).
2. I don’t think the computer simulation thought experiment works (at least with our current idea of computers), because our experience is grounded in the most fundamental level of reality (not completely captured by current models of physics).
3. Remember, what we currently think of as fundamental laws of physics (the twin towering achievements of general relativity and quantum field theory) are not, actually, fundamental (this is why the hunt is on for a theory of quantum gravity). I think these laws emerge from a more basic level which is composed of a causal network of elementary quantum events. I’m betting a successful theory of quantum gravity will be of this sort.
4. I think time (true time, not the geometric time of current physical theories) is the dimension of experience. As experience is fundamental, so is time. Just as (Chalmers’ argument) you can’t get first person experience from purely third-person facts, you can’t get the flow of time from a static geometric model of a time axis.
5. I obviously liked Smolin's account of why the geometric description of time – where the present moment and the flow of time can be ignored – is not going to be part of a fundamental theory.
6. I like Greene’s books, but on this issue I’m with Smolin and disagree with Greene.

Thanks, - Steve

Allen said...

1. On circularity: I’m proposing a monistic system

So, what is, exactly, an experiential unit? How fine grained are your proposed experiential units? Does one experiential unit equal one instant of perceivable experience, and thus could be defined as the smallest consciously detectable moment of time? Or do you need a lot of experiential units to come together to "construct" a consciously detectable moment?

Would it be correct to say that an experiential unit is also a unit of information? Information about an experience?


2. I don’t think the computer simulation

So you reject the idea that a computer simulation could be conscious, even if it acted as thought it were conscious, and claimed to be conscious? Or do you say that a computer simulation WOULD be conscious, but only because it also tapped into an underlying substrate of "experiential units"?


3. I’m betting a successful theory of quantum gravity

I don't see how quantum gravity has anything to do with consciousness, or experience, other than as an implementation detail of this particular universe that we perceive. Does quantum gravity derive from experience, or does experience derive from quantum gravity? Or are the two totally unrelated?

Is your theory of consciousness specific to the laws in this universe?


4. I think time is the dimension of experience.

I think this is EXACTLY right, and I will lift that line from you for future use. However, I think that this "experience" time is not the same as "physical time", if physical time even exists. As I mentioned (and I think demonstrated) in my initial post, I think that external time, if it exists, is irrelevant.


5. and 6. I'm not a physicist, so I can't judge Greene vs. Smolin. Instead I'll just restate that I think the details of what we percieve are not necessarily useful in explaining why we have conscious perception.

Physics is certainly great for describing what we perceive, but not why we consciously (instead of mechanistically, p-zombie style) perceive it.

Steve said...

I'll go backwards this time.
5 & 4, we're in agreement.

3. The reason I bring up quantum gravity is that I hope/expect that a successful theory will unite the explanation of experience with a fundamental theory of physics (as opposed to this disjunction you and I both observe now). A causal network of quantum events, which we will also intrepret as experiential events, gives rise to everything in the world. The laws of physics as we now think of them, emerge as regularities beyond a certain scale.

2. My point on computers was just a practical one. While everything in nature has a touch of experience (panexperientialism), replicating our human experience successfully would require modelling everything down to the quantum level (maybe a large quantum computer could do this someday). Present day computers implementing a classical system at a course-grained level (electronic on/off switches) can't do the job.

1. An experiential event is by hypothesis the basic unit of nature. It would also define the minimum length of time. I guess it would probably exist at (or below) the planck scale. (To leverage this tiny unit of experience to the rich robust human experience takes a system consisting of a huge number of these units working together in the right way.) Each experiential event could be seen as a unit of information influencing events further up the causal chain.

Allen said...

>> I'll go backwards this time.

Show off...


3. The laws of physics as we now think of them, emerge as regularities beyond a certain scale.

SO, your theory of consciousness is tied exclusively to this universe? If other universes with different phyiscal laws exist, or are conceivable, they could not contain conscious entities unless those universes also have some sort of "experiential units" at the core of their physical laws? SO...any conceivable universe which operated by non-experiential physics could potentially have philosophical zombies?


2. everything in nature has a touch of experience

SO, if we do eventually come up with binary/digital computer simulations that mimic the behavior of humans, these simulations would be conscious in some way. BUT in a potentially very different way than humans, EVEN IF the comuter simulation's behavior is basically identical to ours?

I think this might be a problem for your theory. This SOUNDS like you could apply Chalmers' "Dancing Qualia" thought experiment to it.


1. An experiential event is by hypothesis the basic unit of nature.

I'm not sure I see how your approach really gets us any closer to understanding consciousness. It sort of seems to me that using your reasoning, we could just by fiat say "quarks are units of experience and when you combine quarks in just the right way you get human consciousness". While if this approach eventually unites QM and Relativity, that will be great, but it doesn't seem like it does much to explain consciousness.

Also, I have difficulty in seeing how the inclusion of experience is going to contribute to this unification, unless you're going for explaining wavefunction collapses.

Do you have a good idea for how lots of little "experiential units" come together to create a single unitary subjective experience of seeing a red apple, or tasting a strawberry, or being mad at your neighbor? Is there a bunch of little "anger" particles out there? And "sweet" particles, and "tart" particles, and "red" particles?

I think that there are two totally distinct problems, which don't overlap at all:

1) Explaining the world that we consciously perceive.

2) Explaining that we consciously perceive anything at all (much less this particular world).

The easy problems of consciousness fall under 1, along with lots of other things like quantum physics.

The hard problem of consciousness is 2).

PeterJ said...

May I join in?

Chalmers' theory of information is, as far as it goes, equivalent to Nagarjuna's theory of emptiness, which is the philsophical foundation or expression of Mahayana Buddhism.

The difference is that the latter is fundamental. Perhaps one day physcists will take this theory seriously enough to attempt to falsify it. Until then I see no reason to suppose it is false.

For Nagarjuna space-time and consciousness would be emergent. Psycho-physical phenomena ('dhamma' or 'thing-events')would be information for some consciousness.

Peter

PeterJ said...

Aplogies for the typos. Forgot there's no edit function here. Peter

Steve said...

PeterJ: Welcome. That sounds interesting. Would emptiness be neutral, then, neither experiential nor non-experiential?

Allen: I’m sorry, I don’t think I was explaining myself very well. My idea is that the experiential events are not exclusive to our world, but are fundamental in all worlds. The causal network they form may coalesce into different physical laws in different worlds (or at different epochs/regions in a single world). This causal network is not itself characterized by “laws” (in the usual fashion where initial conditions + equations = determinant result).

With the computer simulation, I haven’t really addressed your thought experiment well, because I guess I just don’t believe in the premise. The computer won’t completely replicate behavior or consciousness unless it can be modeled down to the quantum level.

(BTW, I do think the fundamental events are quantum measurement events.)

I guess I’m not solving the hard problem; I’m inferring from the hard problem that raw experience in fundamental. As you note, that leaves us with the combination problem of how micro-experiential units come together sometimes to form a robust mind with all of its interesting contents. That would be a practical scientific question I think, not a philosophical one: hence my particular interest in quantum biology.

Steve said...

Also perhaps relevant to the information and computer simulation topics in this thread is Seth Lloyd's work on conceiving the universe as a quantum computer. (I have three posts on this under the tag "Seth Lloyd" on the sidebar.) I'm going to go back and think about this some more.

Allen said...

> I'm going to go back and think about this some more.

Ah! Very good! I've been thinking about your position as well.

I'm a little taken aback that you deny that digital computer simulations of brains are even theoretically possible. I agree that they may not be PRACTICALLY possible...but theoretically impossible??? Hmmmm.

I assume your familiar with the whole thing with "replace one neuron with a synthetic digital neuron that replicates it's functionality, are you still conscious"...and then another and another and another...until the whole brain is running on digital neurons?

To me, functionalism makes a lot of sense. I mean, if you replace one small part of a large complex system with a functionally equivalent component...then the system ought to keep working undisturbed.

But I guess that doesn't fit at all with your view, because you say that it's impossible to create a functionally equivalent components for a neuron. BUT...while it may be practically impossible, I can't see any specific reason why it would be theoretically impossible.

To me "the quantum nature" of consciousness sounds a little to mystical. I think the brain is like a digital computer...it uses quantum physics to build a system that reliably processes information. But the workings of that system can be abstracted away from the underlying physical system and re-implemented on top of a different system (multiple realizability).

Even digital computers, with their discrete binary states, rely on quantum processes to work. But they are designed so as to operate reliably and "classically". And I think the human brain, though evolved and not designed, is about the same.

And I haven't seen any evidence to the contrary. To show that quantum processes are involved in biology doesn't mean much to me...quantum processes are also involved in microchips!

On a related note, I've posted a lot over on this thread, though I think most of it assumes functionalism, so it may not be your cup of tea.

http://schwitzsplinters.blogspot.com/2009/01/dust-hypothesis.html

I'd be interested to hear your opinion, if you have time to wade through all the comments!

Steve said...

1. Re: practical vs. theoretical possibility of simulation. I think the brain employs non-trivial quantum effects (coherence, entanglement, tunneling, zeno effect). Some of these have been simulated with classical computers but I think with an exploding demand on computing power. Also, more generally, the specific causal configuration of the micro-level structure may be important (down well below the level of the neuron). With that said, the line between practical and theoretical is not completely clear to me – but hopefully you see where I’m coming from.

2. Re: functionality. I’m with Chalmers here – no amount of third-person description of structure and function will get you first-person experience.

3. Re: dust. That is a long comment thread! I will take a look. But in addition to the functionalism, the causality aspect is a problem. I subscribe to an event or process view of things – not a substance or material view. The brain is a causal network of events where the local time-sequencing is a necessary aspect of the thing.

Allen said...

> I think the brain employs non-trivial quantum effects (coherence, entanglement, tunneling, zeno effect)

It seems to me that every non-trivial physical system employs those effects to one degree or another. Microchips, brains, plants, chairs, everything. We live in a universe where the physical foundations are quantum mechanical in nature, and so everything that we see is the way it is because of the quirks and qualities of quantum mechanics.

Even if you say that there is one very special pure aspect of what the brain does that depends on, say, coherence in a way that the properties of my chair doesn't -- While interesting, I don't think that this would really change anything about my views of consciousness. It still just means that consciousness is a result of the information that is processed and represented by a physical system. A quantum mechanical physical system.

Consciousness isn't in the atoms of the system. It's in the information represented by the relative states of large numbers of atoms. Which is to say: the human brain isn't conscious...it's just a bunch of atoms. Rather, the information represented by the human brain is conscious.

As I mention over on the other thread:

"For instance let's say you write an arabic numeral 2 on a piece of paper. And let's say you carve a roman numeral II into a piece of rock. And let's say you have a byte with a binary value of 2 (00000010) stored on your hard drive. All three of these map to the same abstract concept of "2", even though they have very different physical representations.

Obviously, a piece of paper with ink on it is not the same as a rock with carvings on it. And a dust cloud is not the same as a brain. But the paper and the rock can serve the same purpose (function)...representing the abstract value "2"."

The same information can be represented in many different ways. The same information can be processed in many ways (again, I refer you to the domino boolean logic gates, http://www.youtube.com/watch?v=SudixyugiX4).

> no amount of third-person description of structure and function will get you first-person experience

I agree. Like Chalmers, I think first person experience is a fundamental aspect of information. As Chalmers says: "Experience arises by virtue of its status as one aspect of information, when the other aspect is found embodied in physical processing."

When it comes to applying this to the physical part of reality, I focus on the "embodied"...that's the only role that the physical world plays...and actually I don't even think it's that important a role. The physical world "embodies" or "instantiates" information. End of story. Any physical world can do that. There's nothing special about our particular physical world...IF our world even exists in a physical sense...maybe it only exists to the extent that we perceive it.

As for causality, I'm getting ready to make another post on the other thread about this. But, in short, I think causality is a feature of the implementing physical system, and isn't necessarily relevant to the consciousness, as consciousness is a feature of the information represented by the system, and not of the system itself.

> I subscribe to an event or process view of things

So what is it about these events or processes that give rise to consciousness do you think? Is it their informational content? If so, then why would the same information represented in a different form not also give rise to consciousness? It seems to me that you tie consciousness very closely to the physical materials that host it. If you say that "events or processes" are not material, then what are they?

If you say that they are purely "mental" or "experiential" in nature, how is that different than being physical? Other than being different words I mean? It seems to me that you say "experiential", but it usually to me ends up sounding like something from physics, with strings, or energy, or what have you.

To me it sounds like if we just assign "experiental" properties to quarks or strings or whatever by fiat, and then otherwise proceed with physics as normal, then we aren't too far from your theory.

If Newtonian or Relativistic phsyics aren't a good model for explaining consciousness, why would a quantum mechanical model be?

It seems to me that physics, and physics-like theories (which is how yours sometimes sounds to me), are fundamentally third-person descriptions of the world. And I don't see any way to get from there to an explanation of first person experience.

I think that the Sherlock Holmes approach is the correct one for investigating and explaining the nature of consciousness and reality: "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."

And I think this approach really leaves you with just pure platonic "information" as the fundamental basis for both consciousness and reality.

Steve said...

Experience & Quantum Events

Thinking back to our original discussion of time and experience: Experience flows – it moves. I think a quantum measurement event is the only thing in physics which has the potential to encapsulate an elementary extended process which, when linked together with other events, can give rise to the flow.

In a quantum measurement event, a quantum state (characterized by a wave equation and encompassing many possible outcomes -- points in a platonic phase space, perhaps) is actualized into one specific concrete result. This actualization is a process worthy of being the root of conscious experience (it can be seen also as a “processing” of information, I think).

I contrast this event ontology with an ontology inspired by the classical picture of particles in a space-time container: here we have static configurations of stuff (even if we call them instantiations of information) which in our physical descriptions have relationships but not flow. (Motion in time is just depicted geometrically but there is no actual home for the present moment or for time’s flow.) I see no way to derive conscious experience from such a picture.

By the way, with regard to my postulating the brain’s utilization of non-trival quantum effects, I disagree with the way you characterized things: while all physics is ultimately quantum mechanical, virtually everyone seems to think that uniquely quantum effects wash out and can be ignored above the sub-atomic scale – one can assume a classical picture is good enough. The hypothesis is that the difference between a human (and other living things) and rocks and tables is that of a special organization which leverages the quantum realm to a larger scale.

Steve said...

Allen, you also said:
>And I think this approach really leaves you with just pure platonic "information" as the fundamental basis for both consciousness and reality.<

I actually like this statement alot - but you need a mechanism to pick out the path of consciousness through reality. Here's my thought:

The actualization process of a quantum measurement event (also the atom of experience) picks out an actual event from the possibilities in the platonic realm. The causal network of these events comprises the actual world (picked out from the much larger platonic multiverse or megaverse, which includes all possibilities).

Allen said...

>> I see no way to derive conscious experience from such a picture.

Hmmm. I think you are still not separating "information" from "matter". There is the information, and then there is the medium used to store the information.

So it seems to me that you keep looking at physical matter and saying "how can this inanimate matter give rise to consciousness". And the answer is: it can't. The matter isn't conscious. Instead, it is the information that is represented (stored) by the matter that is conscious.

For instance, the atoms of my brain. They are not conscious. Most of them will be replaced within a year, but at the end of the year I will be basically the same person. Also, if you take my brain and squish it into a pancake, it also is no longer (recognizably) conscious. All of the atoms are still there. But, they no longer are configured in such a way as to represent the information that makes up an "Allen". And so "Allen" is no longer accessible in this universe.

BUT, if you could simulate my brain with a computer, then I believe the simulation would be conscious and would basically pick up where my "pancaked" brain left off. Because the computer simulation would retain and be able to represent the information that makes up the conscious "Allen".

So, I think that our different views of time are not at the core of our disagreement. I think it's our different view of where consciousness really resides. I say it resides entirely with "information". And information is multiply realizable.


>> uniquely quantum effects wash out and can be ignored above the sub-atomic scalea

You seem to be implying that these things only happen under "clean" circumstances in a lab. But I think that isn't correct. They happen all the time, though, as you say, only at the microscopic level. So I'm not saying I expect my chair to tunnel through the floor into the apartment below me. Instead, what I'm saying is that the macroscopic properties of everything around us depend on these uniquely quantum processes taking place at the microscopic level, including tunneling and whatnot.

Quantum effects DO wash out...and what they wash out TO is the normal "classical" seeming world around us. Quantum effects come into play with electronics, in all sorts of chemical processes (including but not limited to biological ones), and even with chairs. If these quantum effects weren't there at the bottom, things would look very different here at the top.

See: http://www.lbl.gov/Science-Articles/Archive/PBD-quantum-secrets.html, also google "hydrogen tunneling", or "carbon tunneling".


>> but you need a mechanism to pick out the path of consciousness through reality

I think this is an artificial constraint. Why must there be only one path through reality?

I think consciousness takes ALL paths through reality. You could think of this as in the Many Worlds Interpretation. However, I prefer an even more abstract conceptualization as sort of a "platonic mindscape".

Steve said...

Allen: you've got this platonic landscape of information which includes all possibilities. Good. What keeps this from being a static timeless entity? Why/how, in your view, is information realized/experienced or whatever?

Allen said...

Well, first, I think you said it pretty well earlier: Time is the dimension of experience. But experience is an internal "psychological" concept, not an external concept. Therefore "time" is also an internal feature, not necessarily an external feature.

So it seems to me that we have have no direct access to the physical world. Information about the physical world is conveyed to us via our senses. BUT, we don't even have direct conscious access to our sensory data. All of that sensory data is instead apparently heavily processed by various neural subsystems and "feature detectors", the outputs of which are then reintegrated into a simplified mental model of reality, and THAT is what we are actually aware of. That mental model is what we think of as "the real world". So it seems to me that we can already think of ourselves as living in a world of abstract information.

The same is true of time. We experience time only because we represent that experience internally as part of our simplified model of the world. If there is an external time, it could be altered in many ways, but our internal representation (and experience) of time will remain unchanged. This is kind of what I was getting at with my very first post.

And also you can go back to the computer simulation idea and think about various scenarios. If you and your environment were simulated on a fast computer or a slow computer...you wouldn't be able to tell the difference. If the computer ran for a while, then the simulation data was saved and the computer turned off, then a year later the computer and the simulation were restarted where they left off, you would have no way to detect that a year had passed in "external" time. To you in the simulation, it would be as though nothing had happened, because the computer simulation would pick up on the same exact calculation where it had left off. There was no interruption in your experience of time.

AND, also, as I mentioned before: I agree that experience and consciousness requires changes of state, but I don't agree that it must be change with respect to an external physical "time" dimension. The best analogy that I have heard is that if you have a non-horizontal line, it's Y value changes with respect to the X axis. So some piece of information (the Y value) "changes" with respect to another set of values (the X axis). But there is no time involved in this type of change.

Your experience of the X axis will depend on how you represent the X axis internally in your model of reality. Maybe you will experience the X axis spatially...maybe you will experience it chonologically, maybe you will experience it some other way entirely. Your experience of it depends entirely on how it is represented internally in the information that produces your conscious experience.

You can take any time based event and translate it into a spatial representation, right? For instance, music. You take something that you listen to in time, and write it out as notes on a sheet of paper. No information is lost, in that you can take the sheet music and turn it back into sound. Just an analogy, but maybe it gets the idea across...you can have static representations of "dynamic" processes.

This is in the same vein as the "block universe" idea of Einsten, Greene, and others. So I think all of my proposals have pretty direct parallels in the world of physics (even the platonic mindscape), none of them are "out of the blue".

>> Why/how, in your view, is information realized/experienced or whatever?

I come to the conclusion that consciousness is information by way of process of elimination, as with the Sherlock Holmes quote. I can think of experiments or scenarios where you can do away with everything except information and still get behavior that seems conscious and which therefore I assume is actually conscious. Information is the only common factor in all situations where consciousness seems to be in evidence. And really, it doesn't seem that counter-intuitive to me that information is ultimately what makes me what I am.

So, I agree with Chalmers that the idea that some (all?) information is conscious in some way is a fundamental aspect of information, and not really reducible to more fundamental descriptions or processes. Which again makes sense...how can you get more fundamental than "information"?

Allen said...

On a related note, I agree with at least 90% of what this guy is saying:

http://www.hpcoders.com.au/theory-of-nothing.pdf

Steve said...

Thanks for the link. I will check it out.

I agree with you on a lot of things, but there is one key difference which I guess I have not articulated well. I'm a bit frustrated that we were talking past each other a bit.

I think a block multiverse containing all possible information configurations can easily be seen as a static entity lacking causation, a true flow of time, and experience. I don't think it is enough to stipulate that "some information is conscious". And in your more detailed responses, while you discuss the nature of conscious experience and the internal flow of time and how they relate to information, I still can't find an explanation for why experience or internal time should exist at all. It seems assumed rather than explained.

What is needed is a fundamental process which (forgive me) breathes fire into information and gives rise to experience. That is what I was trying to convey with my experiential/causal/quantum measurement event ontology.

Allen said...

Sorry about the delay on the reply, I've been thinking it over!

>> I'm a bit frustrated that we were talking past each other a bit.
>> That is what I was trying to convey with my experiential/causal/quantum measurement event ontology.

So quantum measurement seems like a slender reed to hang anything off of, as it's not even clear what is involved here. Wave function collapse, Copenhagen, many worlds, many minds, something else? Who knows? Any theory of consciousness that depends heavily on this is doubly speculative I think. Speculative squared. Speculative once because it's a theory of consciousness, but then speculative squared because it hinges on a particular interpretation of Quantum Mechanics! Though if you have some articles or papers you could point me too that you think are pretty convincing I will definitely take a look.

But the idea that a conscious observer is required to collapse a wave function AND that wave function collapse is crucial to the production of consciousness sounds...circular.

HOWEVER, I do understand your reluctance to embrace a timeless view of things. But looking back, I think I first came to the view that consciousness was informational in nature (via Chalmers). And then I started wondering how that fit with time and causality. And ultimately came to the conclusion that information is independent of time and causality, and thus consciousness is independent of time and causality.


>> What is needed is a fundamental process which (forgive me) breathes fire into information and gives rise to experience.

So, I think I'm taking a "deductive" approach to explaining consciousness (http://en.wikipedia.org/wiki/Deductive_reasoning), and you seem to want to take an "inductive" approach (http://en.wikipedia.org/wiki/Inductive_reasoning).

We know that consciousness exists. We know it has something to do with the brain (in that significant changes to brain state are usually accompanied by changes in experience, and as far as has been observed changes in experience are always accompanied by changes in brain state). So we just need to explain consciousness in terms of what we know (or can find out) about the brain.

But instead of using physics to explain consciousness, as you seem inclined to do, I think something more like information theory, or theory of computation, or some form of mathematics or logic is what you need to understand consciousness.

So my deductive argument is:

Major Premise: All aspects of human mentality are computational/informational in nature.
Minor Premise: Consciousness is an aspect of human mentality.
Conclusion: Consciousness is computational/informational in nature.


>> It seems assumed rather than explained.

So my approach is to look at the available evidence about human mentality and from that try to deduce where consciousness comes from.

1) It seems to me that the mind "supervenes" on the brain.

2) It seems to me that if the brain's function is unaffected, consciousness is unaffected.

3) It seems to me that if you replace a tiny portion of the brain with a functionally equivalent component, the mind would still supervene on the brain.

4) It seems to me that if you replaced a large portion of the brain with functionally equivalent components, the mind would still supervene on that brain.

5) It seems to me that if you replaced the entire brain with something functionally equivalent, the original mind would now supervene on that new "functionally equivalent substitute" of the original brain.

SO, how do we determine whether a substitute-brain is functionally equivalent to the original brain? Well, we can't necessarily just check verbal or external behavioral output, as internal experience is really what we want to explain. So we could instead test to see if we can retrieve equivalent information from the original-brain and the substitute brain at any given point in time. In other words, can we "map" from the state of the original-brain to the state of the substitute-brain.

Let me make this further crucial point: A neuron does SOMETHING that contributes to the function of the brain and thus to the overall package of human abilities. But I seriously doubt that EVERYTHING that the neuron does contributes to human intelligence and consciousness. Much (most?) of what the neuron does is just stay alive as a cell. Staying alive is a necessary precondition for the neuron to play it's part in generating intelligent behavior, but it is not a part of what the neuron contributes to that collective intelligent behavior.

So we should (theoretically) be able to abstract out exactly (an only) what it is that the neuron contributes to intelligent behavior and just focus on producing a component that is functionally equivalent in that sense.

So I could go into more detail, but I'm sure you see where I'm going, and you've undoubtedly heard it before. But this is the core of my "explanation". Human intelligence and consciousness boil down, ultimately to the information referred to in the previous paragraph.

It seems to me that your counter-argument to the above is that it's impossible to have something functionally equivalent to a neuron. Which doesn't sound like a reasonable claim to me. "Impossible" is a extremely strong assertion. It may not be practical to create a "substitute-neuron", but surely it is theoretically possible.

If you think otherwise, then I'd be interested in hearing your reasoning.

Steve said...

>>Sorry about the delay…

No rush. I appreciate the dialogue.

>>So quantum measurement seems like a slender reed…

I view the interpretation I’m giving to the quantum measurements as a supporting argument for a philosophical view which started elsewhere. The beginnings for me were in the debates in philosophy of mind, which pointed me toward panexperientialism (have you see Justin’s page of links here?). Then when turning to ontology and causation, the event ontologies of Russell, Whitehead and Gregg Rosenberg are examples of how experiential events can be fit into an explanation of the constitution of the natural world. Quantum measurement and its ineliminable reliance on an observer’s point of view strikes me as a posteriori evidence for this metaphysics (relational or perpectivist interpretations capture this best).

>>And ultimately came to the conclusion that information is independent of time and causality, and thus consciousness is independent of time and causality.

As we’ve talked about, I see the truth of the first statement (because I think information includes possibilities beyond our local time/causality), but the second one seems wrong to me. The flow of time is an intrinsic aspect of consciousness; if you depict time geometrically and create an abstract picture devoid of this flow, you’re missing out on consciousness.

>>So my deductive argument is:

I agree that, given consciousness, we might conclude that it is informational in nature. However, given a theory that information is ontologically fundamental, I don’t see how you would ever derive consciousness (with its distinctive flow of experience) as a necessary part of this landscape of information.

I think the information-theoretic version of my view would go something like this: All information configurations exist in a platonic sense. Some of this information is actualized (made concrete) via being processed in a experiential causal event. (Perhaps all information is being processed somewhere in the multiverse, but we can only be in touch with our local region.)

>> your counter-argument to the above is that it’s impossible to have something functionally equivalent to a neuron.

If I said that, I officially back off that assertion. What I’m sticking to is that any classical functional description will leave out the part where experience is grounded; I say that is at the level of quantum events.

Steve said...

One thing I think is interesting about quantum computation as opposed to classical computation: a quantum computer just IS a quantum physical system, as opposed to a classical computer which can be instantiated in so many ways. I think this might be relevant to the issue of what is special about biological systems vs. classical computational models of them.

Allen said...

Okay, I'm still reading on all of the panexperiantial links. And also trying to figure out HLSL (High Level Shader Language) for work. So it's going to be a while!

But, I'd like to go ahead and respond to some of your other points:

>> The flow of time is an intrinsic aspect of consciousness

So I say that Time derives from Consciousness. Not vice versa. Time IS an aspect of consciousness...and thus doesn't exist seperately from consciousness. The quote from Brian Greene that I posted before I think basically sums up my view on this. The movie frame analogy, where static snapshots combine to create the illusion of continuous flow, seems reasonable to me.


>> I don’t see how you would ever derive consciousness

Exactly. I don't think you can derive consciousness. The fact that some forms of information are conscious is asserted as a fundamental principle whose existance has been deduced by observation of the world we live in. So it isn't derived, it's deduced.


>> All information configurations exist in a platonic sense. Some of this information is actualized

I don't quite understand your insistence that only some possible worlds are actualized. Where does that come from?


>> Perhaps all information is being processed somewhere in the multiverse, but we can only be in touch with our local region

Exactly. This is consistent with Many Worlds Interpretation, right?

Allen said...

>> One thing I think is interesting about quantum computation as opposed to classical computation

I did come across this paper (http://arxiv.org/PS_cache/quant-ph/pdf/9812/9812037v1.pdf), and in particular this part of it:

"The Turing machine model seems to capture the entire concept of computability, according to the following thesis[62]:

Church Turing Thesis: A Turing machine can compute any function computable by a reasonable physical device.

What does “reasonable physical device” mean? This thesis is a physical statement, and as such it cannot be proven. But one knows a physically unreasonable device when one sees it. Up till now there are no candidates for counterexamples to this thesis (but see Ref. [103]). All physical systems, (including quantum systems), seem to have a simulation by a Turing Machine."

What do you think about that last sentence: "All physical systems, (including quantum systems), seem to have a simulation by a Turing Machine."?

Also, SEP had a good article on Quantum Computing, and how it relates to classical computing: http://plato.stanford.edu/entries/qt-quantcomp/

ALSO, this (http://eve.physics.ox.ac.uk/Personal/steane/qcintro.html) was a good article I thought, especially the part at the beginning that discusses information, and begins: "Another thing which can be expressed in many different ways is information."

One thing that occurs to me to ask you is this:

Do you think that observed human behavior and ability is too complex and extraordinary to be explained by "classical computation"? Do you think that there is no way to explain our "third person observable" abilities (i.e., all abilities except conscious experience) in terms of the Turing-machine-like computational power of the human brain, without invoking some sort of "exotic" quantum-level computation?

OR do you think that human ability and behavior could be theoretically duplicated by a Turing-machine simulation, BUT that the simulation wouldn't be conscious?

If human abilities require quantum computing, how about the abilities of a mouse? Could those be simulated by a Turing-machine? A worm? Does it turn out that no form of life can be simulated, even in principle, on a Turing-machine-equivalent computer?

Allen said...

The main point in the above links to articles on quantum computing being that: at this time it apparently isn't clear that there is any difference between what can be calculated on a Turing machine and what could be calculated on a "quantum computer".

All that's clear so far is that Shor's quantum algorithm for factoring primes is much more efficient than any known "classical" algorithm.

Right?

Steve said...

Thanks for the links, Allen. I need to read up on the application of the Church-Turing thesis to quantum computing before responding.

On the many worlds interpretation - a difference is that the MWI is motivated by the denial of the existence of a measurement process. I think both the possiblities and the measurement events are part of reality.

Steve said...

Dear Allen: I was drafting a response on the quantum computing issue, but it's getting lengthy. So I'm going to try to turn it into a new blog post.
- Steve