For many people, the phenomenon of consciousness is the best evidence we have that there must be something important missing in our basic physical description of the world. According to this worry, a bunch of atoms and particles, mindlessly obeying the laws of physics, can’t actually experience the way a conscious creature does. There’s no such thing as “what it is to be like” a collection of purely physical atoms; it would lack qualia, the irreducibly subjective components of our experience of the world. One argument for this conclusion is that we can conceive of collections of atoms that behave physically in exactly the same way as ordinary humans, but don’t have those inner experiences — philosophical zombies. (If you think about it carefully, I would claim, you would realize that zombies are harder to conceive of than you might originally have guessed — but that’s an argument for another time.)
The folks who find this line of reasoning compelling are not necessarily traditional Cartesian dualists who think that there is an immaterial soul distinct from the body. On the contrary, they often appreciate the arguments against “substance dualism,” and have a high degree of respect for the laws of physics (which don’t seem to need or provide evidence for any non-physical influences on our atoms). But still, they insist, there’s no way to just throw a bunch of mindless physical matter together and expect it to experience true consciousness.
People who want to dance this tricky two-step — respect for the laws of physics, but an insistence that consciousness can’t reduce to the physical — are forced to face up to a certain problem, which we might call the causal box argument. It goes like this. (Feel free to replace “physical particles” with “quantum fields” if you want to be fastidious.)
- Consciousness cannot be accounted for by physical particles obeying mindless equations.
- Human beings seem to be made up — even if not exclusively — of physical particles.
- To the best of our knowledge, those particles obey mindless equations, without exception.
- Therefore, consciousness does not exist.
Nobody actually believes this argument, let us hasten to add — they typically just deny one of the premises.
But there is a tiny sliver of wiggle room that might allow us to salvage something special about consciousness without giving up on the laws of physics — the concept of downward causation. Here we’re invoking the idea that there are different levels at which we can describe reality, as I discussed in The Big Picture at great length. We say that “higher” (more coarse-grained) levels are emergent, but that word means different things to different people. So-called “weak” emergence just says the obvious thing, that higher-level notions like the fluidity or solidity of a material substance emerge out of the properties of its microscopic constituents. In principle, if not in practice, the microscopic description is absolutely complete and comprehensive. A “strong” form of emergence would suggest that something truly new comes into being at the higher levels, something that just isn’t there in the microscopic description.
Downward causation is one manifestation of this strong-emergentist attitude. It’s the idea that what happens at lower levels can be directly influenced (causally acted upon) by what is happening at the higher levels. The idea, in other words, that you can’t really understand the microscopic behavior without knowing something about the macroscopic.
There is no reason to think that anything like downward causation really happens in the world, at least not down to the level of particles and forces. While I was writing The Big Picture, I grumbled on Twitter about how people kept talking about it but how I didn’t want to discuss it in the book; naturally, I was hectored into writing something about it.
But you can see why the concept of downward causation might be attractive to someone who doesn’t think that consciousness can be accounted for by the fields and equations of the Core Theory. Sure, the idea would be, maybe electrons and nuclei act according to the laws of physics, but those laws need to include feedback from higher levels onto that microscopic behavior — including whether or not those particles are part of a conscious creature. In that way, consciousness can play a decisive, causal role in the universe, without actually violating any physical laws.
One person who thinks that way is John Searle, the extremely distinguished philosopher from Berkeley (and originator of the Chinese Room argument). I recently received an email from Henrik Røed Sherling, who took a class with Searle and came across this very issue. He sent me this email, which he was kind enough to allow me to reproduce here:
Hi Professor Carroll,
I read your book and was at the same time awestruck and angered, because I thought your entire section on the mind was both well-written and awfully wrong — until I started thinking about it, that is. Now I genuinely don’t know what to think anymore, but I’m trying to work through it by writing a paper on the topic.
I took Philosophy of Mind with John Searle last semester at UC Berkeley. He convinced me of a lot of ideas of which your book has now disabused me. But despite your occasionally effective jabs at Searle, you never explicitly refute his own theory of the mind, Biological Naturalism. I want to do that, using an argument from your book, but I first need to make sure that I properly understand it.
Searle says this of consciousness: it is caused by neuronal processes and realized in neuronal systems, but is not ontologically reducible to these; consciousness is not just a word we have for something else that is more fundamental. He uses the following analogy to visualize his description: consciousness is to the mind like fluidity is to water. It’s a higher-level feature caused by lower-level features and realized in a system of said lower-level features. Of course, for his version of consciousness to escape the charge of epiphenomenalism, he needs the higher-level feature in this analogy to act causally on the lower-level features — he needs downward causation. In typical fashion he says that “no one in their right mind” can say that solidity does not act causally when a hammer strikes a nail, but it appears to me that this is what you are saying.
So to my questions. Is it right to say that your argument against the existence of downward causation boils down to the incompatible vocabularies of lower-level and higher-level theories? I.e. that there is no such thing as a gluon in Fluid Dynamics, nor anything such as a fluid in the Standard Model, so a cause in one theory cannot have an effect in the other simply because causes and effects are different things in the different theories; gluons don’t affect fluidity, temperaturs and pressures do; fluids don’t affect gluons, quarks and fields do. If I have understood you right, then there couldn’t be any upward causation either. In which case Searle’s theory is not only epiphenomenal, it’s plain inaccurate from the get-go; he wants consciousness to both be a higher-level feature of neuronal processes and to be caused by them. Did I get this right?
Best regards,
Henrik Røed Sherling
Here was my reply:
Dear Henrik–
Thanks for writing. Genuinely not knowing what to think is always an acceptable stance!
I think your summary of my views are pretty accurate. As I say on p. 375, poetic naturalists tend not to be impressed by downward causation, but not by upward causation either! At least, not if your theory of each individual level is complete and consistent.
Part of the issue is, as often happens, an inconsistent use of a natural-language word, in this case “cause.” The kinds of dynamical, explain-this-occurrence causes that we’re talking about here are a different beast than inter-level implications (that one might be tempted to sloppily refer to as “causes”). Features of a lower level, like conservation of energy, can certainly imply or entail features of higher-level descriptions; and indeed the converse is also possible. But saying that such implications are “causes” is to mean something completely different than when we say “swinging my elbow caused the glass of wine to fall to the floor.”
So, I like to think I’m in my right mind, and I’m happy to admit that solidity acts causally when a hammer strikes a nail. But I don’t describe that nail as a collection of particles obeying the Core Theory *and* additionally as a solid object that a hammer can hit; we should use one language or the other. At the level of elementary particles, there’s no such concept as “solidity,” and it doesn’t act causally.
To be perfectly careful — all this is how we currently see things according to modern physics. An electron responds to the other fields precisely at its location, in quantitatively well-understood ways that make no reference to whether it’s in a nail, in a brain, or in interstellar space. We can of course imagine that this understanding is wrong, and that future investigations will reveal the electron really does care about those things. That would be the greatest discovery in physics since quantum mechanics itself, perhaps of all time; but I’m not holding my breath.
I really do think that enormous confusion is caused in many areas — not just consciousness, but free will and even more purely physical phenomena — by the simple mistake of starting sentences in one language or layer of description (“I thought about summoning up the will power to resist that extra slice of pizza…”) but then ending them in a completely different vocabulary (“… but my atoms obeyed the laws of the Standard Model, so what could I do?”) The dynamical rules of the Core Theory aren’t just vague suggestions; they are absolutely precise statements about how the quantum fields making up you and me behave under any circumstances (within the “everyday life” domain of validity). And those rules say that the behavior of, say, an electron is determined by the local values of other quantum fields at the position of the electron — and by nothing else. (That’s “locality” or “microcausality” in quantum field theory.) In particular, as long as the quantum fields at the precise position of the electron are the same, the larger context in which it is embedded is utterly irrelevant.
It’s possible that the real world is different, and there is such inter-level feedback. That’s an experimentally testable question! As I mentioned to Henrik, it would be the greatest scientific discovery of our lifetimes. And there’s basically no evidence that it’s true. But it’s possible.
So I don’t think downward causation is of any help to attempts to free the phenomenon of consciousness from arising in a completely conventional way from the collective behavior of microscopic physical constituents of matter. We’re allowed to talk about consciousness as a real, causally efficacious phenomenon — as long as we stick to the appropriate human-scale level of description. But electrons get along just fine without it.
Ben,
“The very first is that we don’t have any evidence of any process analogous to dice flipping or coin tossing or whatever that is actually, truly, really random. Even the closest we can come, Everettian Many-Worlds, is not random; it simply has the (submicroscopic overly simplified / constrained) coin coming up both heads and tails.”
No. Not at all. I know you have at least read the posts on this blog about the Born Rule.
How can you explain the Born Rule without finite coin flipping? The only alternative is infinite coin flipping with an finite number of ‘connections’ between otherwise totally independent “levels” (for lack of a better word) of spacetime.
But this could go on and on… like the turtles… and I am one who believes that it actually does go on and on. And why shouldn’t I?
You would certainly agree that the universe has no edge. Right? So things can be both finite and infinite. It only depends on what you are referring to.
Anyway. At some most basic level, there IS some kind of coin flipper that has determined the world in which we live.
Once it was set up, it was totally pre-determined. But we can only see a tiny slice of it from our position.
Ben,
Pretty much in agreement on what you say, though;
“When you move at the speed of light, distance is compressed to zero distance. For the thing moving at this speed (light itself) time does not need to change. It does not stop. It does not slow. It is the same as for you or me on any spaceship.”
There is no change at the speed of light, since all stored energy is converted to velocity, so that is why some describe it as the clock/time stopping. It is also why light is such a good medium for conveying information.
At least you are entertained. Even if I say something like, “Tomorrow becomes yesterday because the earth turns,” I’ll only go so far as to say it makes sense to me. As it is now, physics has string theory, super symmetry, big bang, inflation, dark energy, dark matter, block time, multiverses, multiworlds, etc and they seem to me to have left the tracks a ways back, though I realize it is a pretty powerful belief system to some.
While it is a fairly harmless belief, it should be noted that when the bankers needed to create massive derivatives structures, back in the 90’s to store all the notional wealth starting to be generated, as capitalism metastasized from an efficient transfer of value, to the creation of notional wealth as an end in itself, they went to physical theorists out of MIT, not their own accountants. Possibly because the accountants know too much funny math gets you in trouble, but the theorists think entire universes spring out of any old thought bubble.
Life is strange and looking to get much stranger.
Regards,
JBM
Ben,
I would note though;
“The redshift is caused by RELATIVE momentum. That is all. It has nothing to do with expanding space, other than to be a convienient way of guessing hiw far away things are.”
This is basic doppler shift, which would be fine, if we accept we are at the exact center of the universe. No expanding space, just everything moving away from us.
Moe:
I’m starting to wonder that, too.
John, you keep ignoring this fact, and / or missing its implications.
So, keep that in mind as I, too, try yet another approach.
(Remember: light experiences no time nor distance. Repeat it to yourself, like a mantra, as you keep reading.)
Consider, for a moment, a piano. The speed of sound is the same in all the strings; they’re all made of the same stuff and the tension is adjusted equally. (If you have a problem with that, consider for a moment a violin or guitar where it’s even more obvious. You’ll understand in a moment why I’m picking the piano instead.)
Though the speed of sound is the same, the pitch produced by the different strings is different because they’re different lengths.
At this point, I’d like to urge you to very carefully refrain from asking yourself why the pitches are different, because the analogy breaks down very quickly if you look at it too closely like that. Stay with me, at the same level of analysis, please…this is something of an act of desperation on my part that I’m hoping I won’t regret.
Anyway, ignoring the harmonic resonances and the like that I told you to pay no attention to, we can naïvely see that it’s the length that’s responsible for the frequency of the sound produced by the strings, since all else is equal. Focus on that to the exclusion of the stuff where the analogy breaks down.
Now, consider the inflationary universe at two points in time: young and old. When young, there’s some space between the galaxies, but not much. When old, there’s lots of space between the galaxies. The relative positions are pretty much the same.
We would intuitively (and incorrectly) think of light as leaving one of those galaxies some billions of years ago, chasing after its nearby neighbors, and being frustrated as those neighbors keep running away. It set out on, say, an hundred-million light year journey, only to have the journey stretch on to several billion years by the end because the roadway keeps getting stretched like a rubber band.
If I’ve painted an accurate picture of how you’re imagining this works, that’s both good and bad. It’s good because it means I understand where you’re coming from, but it’s bad because, as I noted, this picture is incorrect.
And that’s because of the mantra you should have been repeating all along.
Because, from the perspective of the photon, the light from the ancient distant galaxy left said galaxy the instant you observed it and crossed zero distance to reach your eye. And, at the same instant, another photon is making a similar zero-distance zero-time journey from the one galaxy to another, only this time it’s from young galaxy to young galaxy.
To us, we can imagine that as something like strings being strung on a piano. Same wire, same tension; it’s just that the one string is longer than the other, so of course it has a lower pitch. (Again, ignore the physics of sound production!)
Understanding that, for photons, all of time and space is compressed to zero…well, that’s at the heart of Relativity. And, until you really, truly embrace and accept and internalize that fact, nothing in Relativity is going to make sense to you.
Cheers,
b&
Ben,
Sorry. That was to Moe.
The problem with your story is that for us, light does not travel instantaneously. Though for the light, there is no change. A lightyear is something on the order of a trillion miles. Pretty fast, but not instantaneous. What is compressed to zero is any frame traveling at C. Say a rocketship accelerated to C would effectively vanish to a point.
A random vote from the Internet:
I agree that there is no formal mathematical proof of the sum of a convergent infinite series, unless one considers “proof by definition” to be such. The sum of a CIS is defined (not formally proved) to be the limit of the sequence of partial sums. We all agree that is a reasonable, workable definition. One could probably make good metaphysical arguments for it. It is not what I call a proof.
Zeno was absolutely right: continuous motion is an illusion; and there is no measurable point at which Achilles is at absolutely the identical x-location along a straight track as the hare. (Before, after, and “I can’t tell” are the only three possibilities, and they involve dividing the distance into a finite number of discrete quantities, the Planck Length.) I don’t know why people continue to sneer at him when he was right all along. Most of them don’t seem to know what he was actually saying. If after he noted that a continuous distance L was composed of L/2, 3L/4, 7L/8, and so on, someone asked him what then is the sum of L/2 +L/4+…, I have no doubt he would have replied “L”. That wasn’t his issue.
I have more on that (pet peeve), but moving along, there is no basis for saying this universe is or is not improbable. All probability calculations require assumptions (e.g., the Second Law of Thermodynamics applies to how a universe begins, not just to t>0). Assumptions are not proofs (see above).
That the speed of light in a region devoid of other electro-magnetic fields is a constant to all observers regardless of whether they are moving with respect to each other is not an assumption or definition. It is a measured, empirical fact. Einstein’s Theory of Special Relativity codifies how this works.
Which is not to say that I myself am not wrong about a lot of things. I know I am, I just don’t which things they are.
P.S. Somewhere in a distant galaxy, far, far, away, all the astronomers are also seeing every remote (from them) galaxy moving away from them in all directions due to the expansion of the universe. Einstein’s General Theory of Relativity predicts this, and also predicts the precession of Mercury and that two orbiting black holes will give off gravity waves with a specific spectrum when they merge. My first example has not yet been confirmed experimentally, but the last two have.
Ben, Moe,
I appreciate the consideration. Most people involved would have dropped out by now.
Yes, the math works, but then the math worked for epicycles as well, because it was based on modeling observations. When it didn’t work, they could just add another cycle. Each of us is the center of our view of the universe. Logically we could, with enough complexity, construct a Bencentric, or Moecentric, or Johncentric model of the universe and it would be accurate, for the simple fact that we do exist as the center of our point of view. But it is the physics that is the problem. Just as when you move across the room, that doesn’t mean there are Titans pushing everything the opposite direction, nor do we insist on further cosmic gearwheels to explain the actions of everything moving relative to us.
So when the theory requires explaining why we appear as the center of the universe, inserting a faster than light initial stage, with no idea as to where this energy came from, or why it slowed down(thus projecting out multiverses), adding enormous amounts of dark matter to explain why galaxies hold together when current theory says they should fly apart, adding an additional 700% energy content of the universe to explain why redshift goes parabolic about 7 billion years out, it reeks of epicycles being added.
I realize many people will go to their graves believing we just need better testing equipment to find all these invisible forces, but there area few, not just me, who think we should push the reset button and start over.
Jim V
Another admirer of Zeno of Elea. Halelujah. Me too.
On probability, I disagree, i.e. IF statistical mechanics is valid, and if time has no definition outside SM, then the statistical argument holds forwards, backwards or indeed ‘sideways’ (i.e. any low entropy state is expected to be an exceptional island in time and space). Personally I believe the first ‘if’ only conditionally, and the second not at all.
Moe:
But that’s the flip side of the coin (if you’ll excuse me). There’s nothing random about a finite iteration of all possibilities; indeed, that’s the exact opposite of random.
There’s waaaaaay too much anthropomorphism, especially of the deistic / theistic flavor, in there for me to sign off on that statement.
Instead, I’d be on board with something along the lines of there being something we can visualize as akin to a coin-flipper the same way as we can visualize an atom as akin to a miniature solar system. We know the latter is useful for some purposes, but isn’t the full story. The former may well be useful, but we can be equally certain it isn’t the full story. In the former case, we know much more about the full story. In the latter case, further knowledge of the story may (or might not) be impossible to attain, but that ignorance in no way excuses declaring the limits of our knowledge to be the foundation of reality itself.
Cheers,
b&
John:
I think that’s your real objection: you don’t like it on aesthetic grounds. Which, frankly, is your problem, not the theory’s.
So, I’ll take your comparison with epicycles and run with it.
The first is that, yes, you’re correct. You can accurately model the Solar System with epicycles. You can especially do so today with computer modeling. However, should you do so today, you’d plot your results. Initially, you’d see some loopy loops. But, as you increased the resolution, the loops would get smaller and smaller and the zoomed-out picture would get smoother and smoother. And somebody would recognize that the limit of that process (never mind Logicophilosophicus says that’s nonsense) is a perfect ellipse. And it wouldn’t take very long at all for somebody to recognize that one of the loci of the ellipse is centered in the Sun. Further, once you’ve made that observation, Newton’s Laws pretty obviously fall out of the works.
That’s pretty much how we’ve gotten all of modern physics. All sorts of observations plotted, curves fitted, math made to fit the curves. And, as it turns out, much of that math — including the bits you’ve got your biggest problems with — are not much more complex than Newton. Hubble’s Constant, for example is (roughly) 70 km/s per megaparsec…the numbers are humongous, but even the ancients could probably warp their brains ’round that math, at least with smaller numbers.
That brings us to your challenge. Maybe modern physics really is as overcomplicated as epicycles. But, first, we know that we’ve got these epicycles perfectly correct, dialed in with amazing precision. Your solution is going to have to come up with the exact same numbers as our epicycles, because our epicycles give us the same answers as observations.
That’s the first problem with your alternate proposals: they don’t even come close to giving the right answers.
Your second problem is that people who do devote their careers to answering these questions dismiss your objections as uninformed, uneducated, and naïve. I’m pretty sure that, were you to complete an undergraduate physics major degree course with passing grades, you’d be equally dismissive of your current alternatives and objections. Even if you went into it with the attitude that you’d just go along with it for the ride, not accepting any of it but just doing whatever you had to get passing grades.
But, if you actually do manage to put together some reformulation of modern physics along the lines of what you’re suggesting…well, that would mean a Nobel for you and amazing intellectual advancement for the rest of humanity. I wish you the best of luck in such an endeavor, but I hope you’ll forgive me if I suggest that I’m not gonna hold my breath….
Cheers,
b&
Ben,
“There’s nothing random about a finite iteration of all possibilities; indeed, that’s the exact opposite of random.”
You have a strange definition of random. At which number of coin tosses or dice rolls does the outcome stop being random and instead become the exact opposite of random?
Moe, I would suggest that randomness is best understood as that which is not deterministic. As it turns out, the Universe seems to be entirely deterministic, meaning that randomness wouldn’t therefore actually exist.
There are processes which are impractical and / or physically impossible to predict and which, after the fact, are observed to have normalized distributions. Coin tosses are a superlative example. In our everyday lives, they’re as random as makes no difference. But, when we actually go ahead and pay attention to the man behind the curtain, we see that these events are as deterministic as clockwork. Everything is as deterministic as clockwork, even if we can’t actually build clocks that work the same way.
I would note the very strong parallels between coin tosses understood this way and Sean’s conception of “free will.” We say the coin is random because we can’t predict which way it will come up. Sean says we have free will, whatever that’s supposed to be, because we can’t predict if we’ll choose chocolate or vanilla. Even if you can construct contexts in which it is useful to pretend that such is the case, we clearly know that it’s not an accurate description of reality.
I’d also further accuse Sean of his own favored bugaboo, of mixing levels of description. The macroscopic complexity that hinders prediction is entirely unrelated to the microscopic determinism, and to ascribe concepts of “freedom” to what is nothing more than our ignorance and / or cognitive limits makes no sense whatsoever. Taken seriously, the less information you have and the less ability to analyze it, the more free you are — an absurdity which should itself be more than enough to invalidate the premise.
Consider the team captains meeting midfield to determine who gets the ball first. They are “free” to “choose” heads or tails while the coin is in the air because they don’t know how it’ll land. But give them the “choice” to know the outcome in advance, and they’ll take that “choice” in an instant. This ignorance is “freedom”? It’s desirable? This is something worth having in some sense?
Cheers,
b&
Ben Goren has posted a zillion posts here, but he has a deterministic model of the universe. The universe is clearly not deterministic otherwise we could predict the future. Yeah yeah there’s chaos theory, but that ‘s not what Ben Goren is talking about, he’s saying that there is no fundamental randomness to the universe. Well, wow, just the sort of thing that would enable evolution to occur via genetic mutation and also give a convincing divide between Present and Past (Mind and Body)
Ben Goren, please shut up a bit.
Ben,
The three most obvious objections, Inflation, Dark Matter and Energy, are not very aesthetically pleasing. They are ginormous fudge factors between theory and observation.
Given your evident selective hearing, it is futile to offer any suggestion, but since you did ask, I would be remiss not making any point, so I’ll just go with the one I’ve been making about time. As you don’t remember it, I suppose I’ll lay it out from the start;
The basic process of conscious perception is flashes of cognition. From which we construct thoughts and narrative. Thus the common perception that time consists of the point of the present moving from past to future events. Physically explaining this process has proven surprisingly difficult, but physics has settled on the notion of an underlaying dimension, along which all these events exist and since the effect of duration seems to be how we experience that underlaying dimension, physics codifies it as measures of duration.
The sense of the present state is dismissed as subjective, if not epiphenomenal and no more central than any particular point in space.
Now this temporal dimension is correlated with the single spatial dimension of distance, using the speed of light as a standard. This relationship is quite integral to how we perceive reality. For instance, measuring the space between two waves is distance, while the rate they pass a point is duration.
There are problems with this definition though, most especially with the question of symmetry, versus asymmetry. Presumably this underlaying temporal dimension is foundational to the events occurring in it, so it would be the same duration if we measure from event A, to B, as from B to A. Just as with space, it would be the same distance from point A to B, as B to A.
So the question is as to why time seems asymmetric, only going from A to B. This is ascribed to entropy. That time moves in the direction there are more degrees of freedom. Which would seem to refute determinism, but that’s another topic.
I do think there are other issues, such as dismissing the present state as being just subjective events, because, among other reasons, the conservation of energy. This would mean no energy is being left in the past, but is transitioning around various configurations. Consequently no additional energy arrives from the future either. This doesn’t get much mention by the physics community though.
As I see it, we are looking at time backwards. Just as we spent millennia trying to figure out how the sun moves across the sky, from east to west, before realizing it is the earth turning west to east, it is the events which actually go from future to past, because they are effects of and emergent from this physical activity we experience as the present state. To use my prior example; Tomorrow becomes yesterday because the earth turns, relative to the sun.
Time is asymmetric because what is being measured, action, is inertial. The earth turns one direction, not the other.
The reason different clocks can run at different rates and remain in the same present, like ones on the ground and in satellites, is simply because they are separate actions. A faster clock will simply use energy more rapidly. Witness the twin that stayed on earth and aged quicker than her traveling sibling.
There is no block time and the “fabric of spacetime” is no more real than those cosmic gearwheels, of epicycles.
Alan Watts used the example of a boat and its wake to illustrate this process, in that the past, the wake, doesn’t steer the boat, the present. Rather the boat creates the wake. Events are first in the present, then in the past. They have to occur, in order to be determined.
Given information into any event arrives from all directions, much of it traveling at the speed of light, there is no frame, other than the proverbial “god’s eye view,” from which the total input into an event can be known before it occurs. So if the input, can’t be known, neither can the output.
It is interesting that we recognize events as subjective, as they are occurring, but once in the past, assume they are forever set, yet the only point of perception, of any event, is from the present and that is constantly altering our point of view. We are constantly reworking our understanding of the past and it does not physically exist, while any residue left is disturbed by observation. Given the energy manifesting these events is conserved as the present, it is as valid to say the present consumes the past, as saying the past directs the present.
What we do measure as time is also known as frequency and this is an effect of action, similar to temperature, which is an effect of frequency and amplitude, as expressions of quantity and rapidity of energy. We could use ideal gas laws to correlate temperature and volume, similarly to how time and distance are related.
Now we often equate time with causation, but often find the relationship confusing. This is the basis of determinism, in that the inertia of past events is the input and cause of current ones.
Causation though, is the energy, not the sequence. Kicking a ball causes it to move, but yesterday doesn’t cause today, because the energy output from one event is not necessarily the energy input into the next, in a particular sequence. The sun shining on a spinning planet creates this effect called days.
Consequently we often find ourselves rationalizing some narrative relationship between what can seem like disjointed events.
Thermodynamic feedback loops are more descriptive of causation, in that while the high pressure acts like energy input, it is the low pressure which guides and directs this energy.
I will leave it here. There are other aspects, but its late and it doubtful you will give much thought to these.
Ben,
As I have stated before, I think the universe is deterministic as well. I only brought up the coin flipping to demonstrate how no intelligence or planning is necessary to build a complete set of all possibilities. It can simply emerge from something as simple as a repeated coin flip.
No matter how complicated anything appears, it can be broken down and described as a part of a set of possibilities that came into being in this way.
I actually think the Born rule could best be described as the result of a translation from underlying basic bits of information into higher order information about the location and identity of particles. (This is analogous to the numbers on a pair of dice being summed. Just as “2” only has one possible basic arrangement, there is also only one arrangement of the die on the left being 3 and the one on the right being 4. However, the total sum being “7” has six possible arrangements).
Some arrangements of experimental results can result from more underlying arrangements of basic bits of information, but we find them to be completely indistinguishable at the level of observable particles.
This is actually less like rolling dice, but more like reading a table of addition. All the boxes are always filled in (determined), but many of the sums are identical to each other. If you were only given a list of sums (and not knowing that they were sums at all) then you would simply have a statistical distribution of numbers.
To simulate a many worlds type splitting, we could start with a 10×10 addition table that lists only the sums in 100 boxes on a piece of paper. Now we cut this up into the single squares and each of 100 isolated people in their own room is handed one square. They don’t know that there are 99 other people in rooms exactly like theirs.
At first, everyone might think that they had a random number. However, only one person got “2”, only one person got “20”, but multiple people got the numbers in between, especially around half way between. So if we repeat the process while randomly jumbling the paper squares each time, then each person will find a statistical distribution eventually.
Now we simply repeat this process, but start with 1,000,000 people. In the first round, they are isolated as 100 groups of 10,000 people each. In the second round, each group is further broken down to 100 sets of 100 groups of 100 people each, and the third round is broken to 100 sets of 100 sets of 100 individuals.
Most people will have seen only numbers in the middle in the three trials and averaged about 10 or 11. Anyone who got a “2” was unlikely to get one again. However, there was absolutely one single person, 1 out of 1,000,000, who got a “2” three times in a row.
This is totally deterministic. All possibilities happened. And this is how multiple worlds can result in the Born Rule.
We just don’t yet understand the basic addition table below our level of observation.
James G
Moe thinks the universe is entirely deterministic – so does Ben. But Ben certainly is not entitled to believe that and believe that “Sean’s Big Equation” gives a complete account of how the universe works. “Amplitudes” are used to find the probabilities of outcomes. The equation insists that our universe is probabilistic, not deterministic.
Apologies to Ben/Moe – I don’t think parties present should be discussed in the third person, which I see I have done (the does-he-take-sugar thing). So please assume I am copying you in, and will answer any substantive reply.
Logicophilosophicus,
‘“Amplitudes” are used to find the probabilities of outcomes. The equation insists that our universe is probabilistic, not deterministic.’
You certainly correct that it appears this way to an observer within the universe.
I tried to make make a bit more clear by imagining that you were in a room all alone and handed random pieces of paper with a sum from an addition table written on it, not knowing that each time you actually had one unique square from a specific set.
I will just assume you read what I put above, and move forward with it.
Each person alone in their room would eventually believe that their entire paper number universe was probabilistic. And for all useful purposes, that is true, because they do not know that the other people exist, and they have no way of asking them what number they received.
This is basically the Copenhagen interpretation. You are the only person in a room anywhere. Each round, some dice are thrown, and you get a square with the only number that resulted.
I’m okay with that, because it works perfectly. The only problem I have is accounting for the dice roll itself. It adds an unnecessary level of complexity.
Superpositions come out fine if after every round of being handed a statistically determined sum, instead of you observing it, you just got put back in a room with all the other people who also had that number, because your numbers are indistinguishable.
And if you don’t check the sum except for every 100 rounds, then lots of things could have occured in between, you could have had a huge amount of different numbers at each round, but nobody can say which ‘path’ you took to get to the sum of “1000” at the end point.
However, if you did check your total sum at round 99, and you had a total sum of “998” at that point, and then you had “1000” at the next round, then you can be positive that you got a “2” at round 100.
By determining your position, you gained an insight that otherwise would be absolutely impossible to know after the next round.
Does that make sense?
Moe
No. Those other people may or may not (I’d say not) exist in their own rooms/universes, but they are never available. I can’t check the sum at 998 – this universe, even in an Everettian multiverse, would be probabilistic.
I agree about the extra intrusive mechanism (the dice) and I have always believed that the how-of-it was Einstein’s beef. But you have added a new intrusive mechanism – the paper allocation – which is fully equivalent to the dice, and at the cost of creating trillions of universes every second. Sledgehammer, nut…
James Gallagher:
I’m not sure what point you’re trying to make. First, Sean himself is an hard determinist. Second, determinism has nothing to do with the practicality of prediction; I can write a fully deterministic computer program to generate seemingly-random numbers, and you’ll never be able to predict the next number the computer is going to choose. Third, if you think I’m implying some sort of Intelligent Design / Fates / Mind of God that deliberately pulls all the levers, including those that dictate the actions of living beings…then you’re so far off the mark that I can only suppose you’ve been reading somebody else and thinking it was me.
I don’t think our host appreciates such behavior as you’re demonstrating. Besides which, John, Moe, and I have all been pretty much matching each other post-for-post, with Logicophilosophicus not far behind, and zarzuelazen and others have been equally prolific in the past. If our host would prefer I shut up a bit, I’m sure he’ll tell me, and I of course would. Until then, if you’d rather not read my words…then don’t. John and Moe at least seem to be getting something out of the current triologue, if nothing else….
Cheers,
b&
John:
Sorry if I’m giving that impression…but the bits I’ve been ignoring have been derived from or used to derive other bits that we know unquestionably are incorrect. If you’ll forgive me, I’ll do that again here.
I don’t think this is a fair assessment. Rather, the present is viewed as no more privileged than any particular point in space. You are, presumably, as you read these words, sitting in a chair in your office or home, or perhaps on a bus using your smartphone. There’s a volume of space at least an hundred billion lightyears across, maybe even infinite, in which your body could conceivably be located, yet you’re not everywhere; you’re just in your one single location. Similarly, there’s at least a baker’s dozen billion years of the past and trillions of years or more in the future, again perhaps infinite, where you could find yourself. Why should it be any more surprising that you’re at a single point in time the same way you’re at a single point in space?
That’s the role that entropy plays.
Space itself is inherently symmetric. There’s no “arrow of space,” no preferred direction, no “up” nor “down.” But, as is instantly obvious when you drop your keys, there is an arrow of space here on Earth. It is oriented to the center of the Earth for all the familiar reasons Newton figured out.
It’s the same deal for time. There’s no arrow of time in physics, either, no preferred direction — and yet we’re all intimately and inescapably going from past through present to future. Why? Well, to riff on your theme, yesterday becomes today not because the Earth revolves, but because entropy was lower yesterday than it is today. And entropy will be higher still tomorrow. Just as you can trace the local arrow of space down to the center of the Earth, you can trace the local arrow of time backwards to the Big Bang when entropy was extraordinarily low.
Sean has several videos where he goes into a great deal more detail on the entropic arrow of time. Naturally, he does the subject a great deal more justice than I ever could. And, while there’s still lots more to figure out about time, especially at the microscopic level…time at the macroscopic level is pretty much completely understood in terms of entropy.
Entropy to the rescue again.
Energy is, indeed, constant and conserved, but entropy is not. And energy can come in low- and high-entropy forms — and work is done not by energy but by entropy. This is apparent, but unfortunately under-appreciated, from introductory physics. After you’ve used your car’s brakes to do work to bring the car to an halt, the energy is still there…radiating away in the form of heat. And you can’t actually do anything with that heat. It’s the same amount of energy as before, but there’s too much entropy in the heat to be usable. Were it not for that inconvenient fact, we could build perpetual motion machines….
We’ve done that exact experiment and disproved your hypothesis. Your watch uses energy at the same rate whether you’re on the ground or in your supersonic jet.
The difference here is between time at macroscopic and microscopic scales — because what’s happening at that scale is described by entropy, even while time in the physics of the microscopic scale is bidirectional.
Determinism is best understood in Laplacian terms. If you have, say, a toy solar system with a single massive central star and one small planet orbiting it, if you know the current position and vector of the planet, you know enough to know the entire past and future of the evolution of that system — and the math to perform the calculation is well within reach of undergraduates. Just that basic information about the system at one given point is enough to holographically extrapolate the entire rest of the system’s history.
I think pretty much everybody can accept determinism at that scale — and would be very hard-pressed to argue against it.
We can add another planet to our toy solar system and the math instantly gets much, much harrier. Even the slightest error in your values for the initial conditions will give you radically incorrect results if you run the model far enough in the past or future — and it just gets worse from there the more bodies you add. But the fundamental determinism is clearly still there.
Physics has remained exactly like that at all levels ever since Laplace. Everything we’ve ever observed behaves the same way. And, frankly, that’s all that Schrödinger’s Equation is: a formulation for you to put in the initial state and the rules by which the system evolves.
Nothing has ever been observed to break this pattern. There are all sorts of practical limits to how far we can run the calculations in what kinds of detail, but, as best we know, an imaginary computer in an universe with physics radically different from ours could theoretically perform a computation that exactly replicated our own universe. (And, of course, there’s every good reason to be confident that we’re not actually such a simulation — this is purely a thought experiment.)
…hope this helps….
Cheers,
b&
Moe:
Yes, I’m at least provisionally on board with all of that.
I would first start out suggesting that, if M-W is correct, your example of handing out cards is a much better analogy than rolling dice. Whatever the branching mechanism, it only makes sense if it is a complete iteration of all branches rather than some sort of stochastic random mechanism sampling them and creating the illusion of continuity by throwing enough tosses at it.
I would next suggest that there is a lot of confusion between such thorough iteration of microstates and an equally-thorough iteration of macrostates. The example of the air rushing to the corner of the room is one. In others, you’ll hear that there might be another “you” in some version of the multiverse that’s an axe murderer, or another Earth where Hitler won WWII, and so on.
You can certainly construct scenarios in which macroscopic divergences hinge on microscopic differences, but you can just as trivially construct scenarios in which imaginable macroscopic conditions cannot possibly occur regardless of the proposed microscopic variation.
For example, I would posit that the number of branches of Many-Worlds or multiverses or however you want to think of it which have histories identical to ours but in which Jupiter starts spontaneously performing a drunken walk through the Solar System at a significant fraction of the speed of light tomorrow morning is exactly zero. And I don’t think I should have to defend that position.
I would also posit that the number of branches in which, right after I type these words, I go on an axe murdering spree, is also exactly zero.
I’d also be fairly certain that the number of branches that were the same up until the point I was born but am today an axe murderer is still zero.
And I’m similarly certain that the number of branches with living rooms of any reasonable description in which all the air has spontaneously randomly rushed to some corner is, again, zero.
Or, in other words, there is a stark difference between “everything that is possible happens” and “everything that is imaginable is possible.” Indeed, I would suggest that there’s far less macroscopic variation between branches than anybody viscerally suspects. Not zero variation, of course — because, again, it’s trivial to manufacture such variation. But even if you use a quantum coin to pick between chocolate and vanilla…the rest of your life in each branch is going to play out very much the same either way.
If you doubt me…go look up a Web page with a quantum coin flipper. First, put a cookie (or whatever) to your left and right, and flip the quantum coin to decide which you’ll eat. Eat the indicated cookie. Then, flip the coin again…but this time, the decision is between eating the second cookie and going on an axe murdering spree. I predict with 100% certainty that, regardless of whether you first eat the cookie on the left or right, you’re not going on an axe murdering spree.
Cheers,
b&
Logicophilosophicus:
This is a common complaint against Many-Worlds and also against multiverses. But it’s an unjustifiable complaint.
Ignore Many-Worlds for a moment. The simplest form of multiverses accepts Inflation as a real thing, and examines the consequences if both time and space are infinite in the exact same sense as naïvely implied by Euclidean geometry. The result is that, if you go some insane distance in some direction (physically impossible to traverse due to Inflation, but pretend otherwise) you’ll find another region of space that’s also Inflating. It has the exact same physics as we observe here, but the initial conditions of its local Big Bang were different and so its galaxies and solar systems and what-not are completely different. Go some other direction and you’ll find another similar-but-different local Big Bang.
But there’s an infinite amount of space and time with all these Big Bangs, and there’s only so many ways that you can arrange “stuff” in initial conditions in a Big Bang…so, on average, every googolplex lightyears or so, you’d come across another Big Bang with initial conditions and subsequent evolution identical to ours. And, on average, not quite so far away, one only enough marginally different for you to have had raspberry jam instead of strawberry jam with your yogurt this morning.
The initial assumption here was simply Inflation plus infinite space and time, but the logical conclusion is indistinguishable from Everettian Many-Worlds. I don’t think you’d consider the “trillions of universes” argument a valid complaint against this sort of multiverse theory…so you similarly shouldn’t consider it a valid complaint against Everettian Many-Worlds.
Cheers,
b&
John, I should add…
Inflation you can observe for yourself from your own back yard with equipment you can buy from Amazon. It’s a big project for an amateur astronomer, but on a scale of a county high school science fair ribbon-winning project.
Dark Energy is the leading explanation for the observed Inflation, but we’ve still got lots of questions about what it is and how it works. Something is causing Inflation and we call that something “Dark Energy.” But the details remain mysterious.
Dark Matter has been directly observed. We’ve used gravitational lensing to map matter distributions of galaxies, and the matter maps very emphatically do not line up with the visible observations. The matter we’ve thus observed is the right amount to describe the observed motions of the galaxies. So there’s absolutely no question that there’s something we can’t see (“Dark”) that has mass (“Matter”) that’s approximately but not exactly located coincidentally with galaxies. There’re all sorts of guesses as to what the stuff is, ranging from exotic particles that the LHC may yet create to primordial black holes to parallel universes. We know for certain that something’s there; the only mystery is what that something actually is.
Cheers,
b&
A couple of points
The generalized Schrodinger equation is deterministic, but the measurement/observation corresponding to the state vector it describes is not.
A computer program or hardware sequential Boolean state machine generating ‘random numbers’ actually generates ‘pseudo-random numbers’. These can be, and in data comms, routinely are, calculated at the receiving end of a system.
Ben,
Thank you very much! It’s been rare that anyone ever offered me a point by point rebuttal.
Yes, I could be any place in space or time, but many places in space can coexist. Can the same be said of time? The argument against simultaneity of the present is that different observers can witness different events in different order. Yet that is observation of events, which requires energy to both manifest those events and convey information about them and it is only the energy which is conserved, i.e. present. The fact we see events in different orders is no more remarkable than when we look up at the night sky and see the moon as it was a moment ago and stars as they were years ago. The specific events of them reflecting/radiating this energy necessarily no longer exist, otherwise the energy would not be arriving at our eyes, for us to see it. So it is the same as someone on a planet around some other star seeing their own star as it was a few minutes earlier and ours as it was years prior.
Consequently there is, physically, only the state of the energy moving about in space and time, like temperature, is an effect of this process, not an underlaying fundament of it.
Consider the premise of vacuum fluctuation as a primal state. The only requirement is a vacuum, i.e., space and its equilibrium being disturbed. The initial effect would be a temperature. Time would only arise with measurable change. There isn’t even enough low entropy to measure.
” yesterday becomes today not because the Earth revolves, but because entropy was lower yesterday than it is today. And entropy will be higher still tomorrow.”
Consider then, that low entropy is a very high order state. The question is how it comes about and Big Bang theory doesn’t answer that, just that the cosmic spring was wound up tight and now it’s unwinding. Not to get too far afield, but I see what would amount to a cosmic convection cycle, of radiation expanding and gravity contracting, with each reaching stages where it is more efficient to go the other direction. Galaxies being the most basic effect. While they might seem ginormous from our scale, if one assumes an infinite universe, they are only slightly past the vacuum fluctuation level and what we experience as the momentum of entropy is little more than sliding around the fluctuations, as they expand out to infinity and collapse back to equilibrium.
As for space, if we eliminate all physical properties from it, then what would be left, infinity and equilibrium, are non-physical. Infinity because there are no bounds, or limits and equilibrium because there is nothing to be disturbed. Zero. So if you are looking for a basis of reality, it is the ultimate freebie, as it needs no explanation or cause. Simply dismissing it because the mathematicians don’t like infinities and the physicists don’t like a non-physical equilibrium, just creates other problems, like self-negating dimensionless points as the basis of everything.
“Your watch uses energy at the same rate whether you’re on the ground or in your supersonic jet.”
Hmm; Is it the same when the two are reunited, or just relative to their own frames? For instance, why does the stationary twin age faster, if not because she had what amounted to faster metabolism, based on a faster nuclear process?
Though if the reason the clock runs faster is because it takes less energy to generate each tick of the clock in the stationary frame, then you would be right, in that they would use the same amount of energy, even if one clock runs faster. Though that still wouldn’t refute my larger argument that time is generated by action, not foundational to it.
“time in the physics of the microscopic scale is bidirectional.”
Why is it bidirectional? Because no irreversible change and thus entropy, is caused at the level being measured? That doesn’t refute time as an effect of change. Duration is not some underlaying dimension external to the present. It is the present, as these actions are occurring and being measured.
“Just that basic information about the system at one given point is enough to holographically extrapolate the entire rest of the system’s history.”
If you consider what I said, I didn’t say determination doesn’t occur. I said it is the result of the event occurring and my argument for why the future cannot be fully known is not because the outcome isn’t determined by the full input of all factors, but that all factors cannot be known prior to the event occurring. Now you would be able to argue, based on a very simple Big Bang model, that at that first moment we know all input into everything, but even in its current form, we have dark energy as a mystery input from somewhere.
The problem is that information travels at the speed of light, so in order to know all input into any given event, we would have to instantaneously acquire that information. An interesting supposition, but somewhat against the laws of physics. Consequently it is only with the occurrence of the event that total input into the event is calculated.
“Nothing has ever been observed to break this pattern.”
Yes, because observation only occurs in the present. If you know the total input and the specific laws governing it, prediction can be 100%.
Regards,
John