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.
Looking again at the post, Sean said:
‘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.’
Sean, is this intended to be a call to limit use of the word ‘causation’ to within layers, or is it intended to be a general statement that layers of analysis should be constructed in such a way as to be ‘airtight’, not requiring or being influenced by other layers? And of the need for inter-layer causation concepts or mechanisms to be eliminated or minimized?
On the side of compartmentalization:
Ultimately, if determinism is upward and absolute within our universe, then so is the accuracy or otherwise of our thoughts and investigations.
In this case, and causation is upward (and reductionism applies), higher layer descriptors and concepts are just ‘narrative’. But this is where I thought you were coming from previously.
Compartmentalization avoids this sort of argument, but seems an arbitrary way to analyse reality.
Back to outcomes of upward causation:
Our conscious deliberations on reality are in reality just more information within the total emergent state space of the cosmos. Their ‘accuracy’ or ‘truth’ are higher level narrative; neither here nor there in terms of their ‘absolute significance’.
So:
Does ‘truth’ have an external (to the universe) validity? Or is it just a narrative emerging within emerged consciousness?
We are all using many words that are clearly consciousness descriptors and can only be experienced by high level organisms, it seems. ‘Truth’ is one we are very interested in. Do these words have external reality? Are they ‘calibrated’ in any way?
Regarding seeing Darwinism as Axiomatic:
People impute conscious attributes downward in Darwinism to explain how we got here. They apply concepts of consciousness to explain how organisms arose and came to be capable of hosting consciousness. The hard line Darwinist even uses this as a cross-level mechanism to explain the origins of life (‘some sort of natural selection at the molecular level’). So its there in the down direction. And in the up direction, as they explain sociology, politics, even engineering, as outcomes of Social Darwinism. (Richard Dawkins actually doesn’t seem a fan of ‘upward causation’ uses of Darwinism.)
Ben,
“And if an inevitable consequence of your theory is the random non-Newtonian migration of air in rooms, then we’ve already got the observations to know that your theory is as wrong as any perpetual motion theory.”
Well, it’s not MY theory. Everett’s multiple worlds interpretation is perhaps now the most popular interpretation among physicists. And time symmetry has been obvious for a very long time. There is no reason why multiple worlds should be only in the future direction, they should also be in the past, just much fewer if them, as the past is defined by lower entropy, and fewer possible states.
So. It could be that there is one, and only one, ‘now’ moment, which ‘flows’ back and forth through all of the multiple possible worlds in each direction of time (or rather it ebbs and flows).
However, in that case, time would be somewhat meaningless as anything other than a direction preferred on a large scale due only to entropy.
And that is what I was saying all along anyway.
Julio Siqueira:
Do you observe consciousness in yourself? I certainly do in myself, and it’s the most visceral and undeniable observation I’ve ever made. And everybody I know would describe their own observations of their own consciousnesses similarly.
As such, solipsism and / or nihilism are the ultimate antitheses of science. There’s no more reason to take them seriously than any other primitive superstition, such as haruspex, philosophy, or theology.
Sean repeatedly makes the point that you can’t mix languages from different levels of description. You can talk about fair coin tosses and you can talk about bell curves, but you can’t talk about the bell curve of a single toss.
Cheers,
b&
John:
No; that’s not what blackbody radiation is. All that blackbody radiation is is the light that all objects radiate as a result of their temperature.
Stuff at room temperature doesn’t have significant blackbody radiation in the visible spectrum, but the elements of your electric stove do. An incandescent bulb is even hotter and thus has even more blackbody radiation, including visible.
There is no such thing as a perfect blackbody radiator, though there’re ways to build devices that’re “close enough” for whatever practical or experimental purpose you might have in mind.
Also worth noting: all blackbody radiation has the same general shape of the curve of their spectral power distributions. All objects emit all wavelengths as part of their blackbody spectra, from ultra long radio to hard X-rays…but they do so in a pattern that graphs roughly like a stretched Bell curve. The peak of the curve is determined by the temperature. If the peak is roughly 3000 K, the light looks like an incandescent bulb. If about 6500 K, it looks like noonday sunlight. If it’s about 600 K, it’s the dull, reddish glow of the forge.
No! A thousand times, no!
The speed of light is absolute. It is not relative to anything.
We’re not comparing light against galaxies in order to figure out the speed of light.
The speed of light is fundamental in the MKS system. The meter (your numerator) is the distance light travels in 1/299792458 of a second. The second (denominator) is the time it takes for 9192631770 hyperfine transitions of Cs133. No matter where you go, no matter what your velocity, no matter what your acceleration, your atomic clock will count just over 30 ticks as the leading pulse of your flashlight makes its way from one end of your meterstick to the other. And, everywhere you look, you’ll see everybody else’s atomic clocks count off fewer ticks than yours. The slowest clocks you’ll see are the ones of those with the highest relative velocities compared with you — but not only will you both agree that it takes just over 30 ticks of their clock for light to traverse their meterstick, they’ll think that you’re the one who’s slow. And the reason you’ll agree that their super-slow clock counts 30 ticks in the time light is traversing their meterstick is not because time is any different for them, but because their meterstick is going to look much shorter to you than your meterstick — at the same time their clocks are ticking slower (from your perspective), their rulers have proportionally changed by the exact amount necessary to compensate.
That’s another way of looking at the reason you can’t go as fast as light. If you’re in the fast spaceship, everything outside you is shrinking. The faster you go, the more the rest shrinks. At the speed of light, everything else shrinks down to zero distance — a dimensionless point. But your own size remains constant. Given unlimited resources, you’d eventually (from your perspective) be bigger than everything else, and yet everything else still has infinite ability to continue shrinking. The confusing paradox is that, as far as everybody else is concerned, you’re the one who’s shrinking smaller and smaller, approaching the size of a dimensionless point — and the reason you can’t go any faster is because you’ve already shrunk to pretty much nothing already.
Does that help at all?
Cheers,
b&
Moe,
I’m not arguing against Everett. I’m almost won over to the M-W camp; I just need to get around to performing some variations on high-school-physics lab optical slit experiments to viscerally ease some remaining doubts.
What I’m objecting to are characterizations of the evolution of the worlds as “random.” The photon may well go through both slits (even though entanglement means we’ll only ever see it going through one whilst a near-identical evolution of the waveform has a very similar “copy” of us seeing it go through the other). But the photon still goes through both slits deterministically, not randomly. The photon does not, for example, spontaneously change into a quark mid-flight.
As such, there’re hard-and-fast limits to what is and isn’t possible. Your (visible optical) double slit experiment is not going to record quarks at the detector, and the air in your room is not going to self-compress in the far corner.
Cheers,
b&
Ben,
“because their meterstick is going to look much shorter to you than your meterstick — at the same time their clocks are ticking slower (from your perspective), their rulers have proportionally changed by the exact amount necessary to compensate.”
So if the argument were being turned around and “space expands,” i.e. longer meterstick, why wouldn’t the clock tick faster, to “compensate?” In order that light take the same amount of time to cross this expanded space/longer meterstick.
I will be greatly disappointed if science is able to prove the existence of God, because that god would be no more than some super being of fields and particles, known and unknown, however I know that is an impossibility. It’s impossible to create Love in a laboratory. Science is wasting its time to disprove God’s existence, may it spend its time on what’s attainable, even then it has its problems, its seemingly intractable mysteries.
John Merryman “So if the argument were being turned around and “space expands,” i.e. longer meterstick, why wouldn’t the clock tick faster, to “compensate?” In order that light take the same amount of time to cross this expanded space/longer meterstick.”
If you want to understand this, do the math! To have a precise understanding of a physics problem, the best thing to do is to draw it out and do the physics. You will find your intuition is an unreliable guide. You can get only so far with qualitative understanding.
Dr. Carroll,
Why can’t a conservation principle be used to define causality at different levels of description? The causal closure of the physical seems to me to use just that so it seems general across all levels.
Kevin Moore:
Yes — excellent advice. But, it must be noted, the math isn’t necessarily easy for initiates.
John, you asked a “why” question which can’t really be answered. Much more importantly is that we observe that the clock doesn’t tick faster — never mind that you, for some reason, seem to think that it should. In reality, the clock actually really does tick slower when observed from elsewhere, even though everything still looks normal up close.
And, indeed, the only way that the clock would tick faster is if there were some sort of “gears” connecting the clock to the light — but, again, that’s the whole point of Michelson / Morley and Relativity and everything else we’re trying to get across to you: there aren’t any such “gears” because there’s no medium in which light propagates, no universal frame against which anything can be measured, no foundation underlying it all. It really, truly, honestly, actually does all hang on nothing whatsoever. That’s why Relativity is about everything being relative. Were there something absolute that we could use as a reference, we wouldn’t have Relativity as the prevailing theory; we’d have Absolutivity.
Forget about your notions of “should be.” Start with the actual observations of “is” that we’ve been trying to convince you really have, no kidding, been observed. Work from there, rather than trying to force reality into what you’d prefer it to look like.
Ironically enough, you’ll have much better luck molding reality to your wishes when you start with an unbiased analysis of what it actually already is….
Cheers,
b&
Kevin,
That’s my problem. The physics doesn’t compute. There is one dimension/metric of space, based on the spectrum of intergalactic light, in which the units expand. While there is another dimension/metric of space, based on the speed of the very same light, in which there are more units. The galaxies are moving away from each other, light takes longer to cross, so the ruler, based on the speed of light, remains the same measure of space, just more distance.
So if there is this underlaying dimension that is so foundational that it determines the speed of light and it isn’t expanding, the the redshifted metric would seem to only be increased distance, not expanded space.
So this wouldn’t seem to solve the issue for which it was proposed; To explain why we appear at the center of this expansion and presumably the universe.
John:
There is no such dimension / metric / denominator / medium / background / whatever. Period, full stop.
That is not the basis of the meter
The ruler on the spaceship in my examples is a plain ol’ ordinary stick with lines pained on it.
There isn’t.
Everything is expanding uniformly.
There’s a trivial experiment you can go and do right now to understand why you appear to be at the center of the Universe. All you need is a couple sheets of cheap paper and a thick black marker and a ruler.
On one sheet of the paper, draw a 1-centimeter grid of dots. On another sheet, draw a 1-inch grid with the same number of dots.
Lay the 1-inch paper on top of the 1-cm paper. If the paper is cheap enough, you’ll see the 1-cm dots beneath. Line the top paper such that, say, the third dot diagonally from the top left are aligned. Now line up other dots similarly. The implications should be very visceral and obvious.
Cheers,
b&
John, if you don’t have time right now to spend with pen and paper, here’s an image from Wikipedia demonstrating the effect:
https://upload.wikimedia.org/wikipedia/commons/b/b0/Expansion_of_Space_%28Galaxies%29.png
But it’s still worth doing it for yourself, as it’s much more viscerally dramatic as you see the center move around as you move the two sheets.
Cheers,
b&
John Merryman,
You’re doing the physics wrong. That’s easy to do though. All students of physics take wrong steps or make incorrect assumptions.
Ben,
Let me go back to my question about your description of relativistic spacetime;
““because their meterstick is going to look much shorter to you than your meterstick — at the same time their clocks are ticking slower (from your perspective), their rulers have proportionally changed by the exact amount necessary to compensate.”
So if the argument were being turned around and “space expands,” i.e. longer meterstick, why wouldn’t the clock tick faster, to “compensate?” In order that light take the same amount of time to cross this expanded space/longer meterstick.”
So how is it that when “space” contracts, time slows with it, but when space expands, time doesn’t increase as well?
John:
Because you’re referring to two entirely different phenomena.
Lorentzian contraction is a consequence of Relativity and explains your observations of things around you moving relative to you. The phenomenon is superbly well observed and described and understood — right up there with “things fall down” and “water is wet.”
Hubble’s Law is a consequence of Dark Energy / Inflation and is a result of the expansion of space itself. And note that we don’t yet have a good answer for what, exactly, Dark Energy actually is — though there’s absolutely no question whatsoever that it’s real.
Or…to go back to that other analogy I keep making mention of…this would be like the Flat Earther confused about why the Sun rises farther north the farther north you go, when it also rises farther north the closer the calendar gets to the Summer Solstice. Now imagine that I’ve just described how the Sun skims the horizon on the Equinoxes if you’re at either the North or South Poles, and how much that would bake the noodle of the guy who’s still looking for the cave where the Sun sleeps at night…that’s the magnitude of mental shift you’re in need of.
Cheers,
b&
I think it would be helpful for you to raise these questions at physics forums and/or the physics stack exchange. They’re great places where you can talk with a lot of people with a strong physics background and the math can be laid out. When it gets to this point, I don’t think these qualitative conversations are the best way for you to get answers.
Ben,
My problem isn’t with Lorentzian contraction.
Hubble’s law is a consequence of basic Doppler shift and inflation and dark energy are both additions, added long after Hubble passed, to patch gaps between theory and observation. If you have been following the subject, Paul Steinhardt has been raising a bit of fuss lately, that inflation creates more problems than it solves.
And to repeat my question, why is it that “space expands,” but we still have the most basic measure of intergalactic space, the speed of light, as a standard against which to compare this expansion? If those galaxies are moving away, such that it takes light longer to cross, then it has nothing to do with Relativity, since the speed of light doesn’t remain constant to the distance.
John:
So close, and yet….
The whole point of Relativity is that the speed of light does not remain constant to distance! That’s why Lorentzian contraction is a real phenomenon — light stays the same, but clocks speed up or slow down and distances expand and contract.
Which is why any objection to Hubble on such grounds simply doesn’t make sense, because we already know that it’s irrelevant.
Cheers,
b&
Ben,
“But the photon still goes through both slits deterministically, not randomly.”
Results can be totally deterministic, but constructed by a random process. If you roll two dice billions of times, it will be a random result each time. If you record the resulting number if it ever comes up at least once, then you will have a list of 12 numbers. You will never roll a 13, because it is not possible. If you plot the distribution, you will get a non-random distribution of those numbers because some numbers can be produced in more than one way, and others can not.
That makes sense, right? So a totally random process can result in a totally deterministic set of possible numbers and a defined statistical distribution.
That is what I mean by random.
Ben said
‘Sean repeatedly makes the point that you can’t mix languages from different levels of description. You can talk about fair coin tosses and you can talk about bell curves, but you can’t talk about the bell curve of a single toss.’
Why? You are both doing it. You and Sean are both using descriptors based on human consciousness all the time in describing and analysing all layers; i.e. human everyday language. Why would a truly objective individual working within naturalistic constraints think their own level is implicitly valid as a ‘final’ lens for analysis of reality?
To re-quote Heisenberg: ‘What we observe is not nature itself, but nature exposed to our method of questioning.’
An implication of this statement is that there is very likely a qualitative limit on what we can understand about reality. It is not a quantitative issue, i.e. a question of merely continuing along the same course. When it comes to rational analysis based on material observations, our humanity is our unavoidable ‘transfer function’ on reality.
Secular humanism and its scientific branches have therefore made implicit assumptions, either by choice or by blindness. We are the valid agent of final analysis. Ours is the top layer. This is a faith position.
Discourses on say QM repeatedly haul one back to everyday perceptions and assumptions. Vectors are compared and contrasted to everyday x,y,z constructs, for example. Operators are equated with everyday measurement. Our ideas on QM certainly developed alongside abstract concepts like imaginary numbers, but the departures from intuitive (for us) constructs are minor.
Stats on events are one thing. ‘Truly new emergent phenomena’ quite another. I see things like ‘determination’, ‘selfless love’, ‘being known and understood from the heart’, ‘mercy’, ‘humour’, or even ‘zeal for truth’, not as ’emergent phenomena’ and/or merely narrative over core physics, but as what life is most profoundly about, and as wonderful gifts and insights From Elsewhere. Their opposites illustrate the dead end; minimized humanity.
Ben,
Which goes to a prior issue. We experience reality as flashes of cognition and so think of time as this point of the present moving from past to future events. Physics codifies this perception by treating it as measures of duration, as though there was some underlaying dimensionality we experience as duration.
The reality is that change is creating and dissolving these events, such that it is they which go future to past. To wit, tomorrow becomes yesterday because the earth turns relative to the sun. Duration is simply the state of the present, as these events form and dissolve.
Spacetime is a bit like trying to explain the motion of the sun in a geocentric cosmology. Just as it is only our impression the sun moves, when it is the earth turning, so to is it the events that are transitory, not the present state.
Different clocks run at different rates and remain in the same present simply because they are separate actions. What is being measured is frequency. Which makes time more like temperature, an effect of frequency and amplitude, rather than space.
The reason time is asymmetric is because it is only a measure of action and action is inertial. The earth turns one direction, not any other.
So to get back to the topic at hand, in a moving frame, it is what we are measuring, light, which slows, but since E=mc2, the structure of mass is also slowed and compressed.
So now, in your prior statement that I quoted,
“because their meterstick is going to look much shorter to you than your meterstick — at the same time their clocks are ticking slower (from your perspective), their rulers have proportionally changed by the exact amount necessary to compensate.”
You point out why the speed of light remains CONSTANT in a moving frame, by both MEASURES of distance and time shrinking proportionally. Then you turn around and say,
“The whole point of Relativity is that the speed of light does not remain constant to distance!”
But that, “clocks speed up or slow down and distances expand and contract.”
So I would point out, the clock is a measure of the speed of light, in the particular frame, not the other way around.
And, most importantly, IT ONLY SLOWS IN A MOVING/CONTRACTED FRAME!! IT DOES NOT SPEED UP IN THE PROVERBIAL EXPANDING FRAME!
If you go back and study the history and evolution of this theory, Huddle’s original assumption was basic Doppler shift. It was only after they studied lots of galaxies and found them all redshifted, proportional to distance, with no variations, creating the impression we must be at the exact center of the universe, that the idea of space itself expanding was proposed, because Spacetime! Overlooking the whole premise of which is that the speed of light is still measured as a constant. Yet if light didn’t take longer to cross, there would be no redshift.
As is evident, when you get lots of people running in the same direction, usually it takes them running off a cliff to get their attention.
John Merryman,
“So to get back to the topic at hand, in a moving frame, it is what we are measuring, light, which slows, but since E=mc2, the structure of mass is also slowed and compressed.”
You are totally cracking me up now. Ok, ok, I get it. You are just having a laugh. Trying to see how many ways people will try to explain something so basic that you pretend not to understand.
This exact statement (at least the underlying part of the statement) has been dealt with probably 10 times on this thread alone.
Just to play the sucker once again, I will make a comment.
Light does not slow in the case that you presented. If I am an indepent observer, and 20 exactly identical spaceships filled with robots glide past at different speeds at the same time (from my point if view), the pre-programmed robots aboard them will seem to be moving around at various speeds ( from my point of view), and they will all be different widths (from my point if view).
However, the light moving around all of their spacecrafts will appear to be going at exactly the same speed (from MY point of view).
And. From the point of view of each of those robots, it is similar. All of the speeds and sizes of the robots on the other ships have changed, but the speed of light remains the same when observing the light moving around each of the other ships as compared to your own ship.
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.
However. To repeat. From the standpoint if light itself, DISTANCE is reduced to nothing.
You do not need to speed up to cover more distance in the same time, if distance has been reduced to zero for every possible distance. Everything is the same distance to light itself! It can not speed up! It can not slow down! Speed is meaningless to a photon.
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.
Hmmm…I think we might be using the language differently, but I at least think I understand what you’re aiming for.
However, there still remain some fundamental questions / problems.
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.
So, right out of the gate, I’d reject a claim that there’s a true random analogue to bitwise coin-flipping beneath it all.
I would consider a possibility that every coin is tossed and comes up both heads and tails every time…but now we get into the problem of time. Are there an infinite number of coin tosses? If so, probabilities and frequency distributions become meaningless. But if they’re finite, then there’s no pretense of randomness; you simply have a mind-bogglingly big unchanging binary number.
Lastly, there’s still the question of implementation. Where’s the computer that’s reading this number from its memory and executing the universe instantiation routine it represents? Numbers don’t actually do anything; they’re simply human language describing stuff we see around us. To say that reality is like a humongous binary number is one thing, but to say that it is such a number has as much meaning as saying that YHWH and / or Jesus Spoke the Word of Life into Being.
Cheers,
b&
Simon Packer:
Sean is literally the first person who will point out that there are limits to our understanding of reality. Every time he pulls up what I call Sean’s Big Equation, before anybody else has a chance to get a word in edgewise, he’s pointing out the ultraviolet cutoff that excludes things like black holes and cosmogenesis. And, if you’ve read through this discussion, you’ll see that I vigorously reject that the very notion of “ultimate reality” is itself incoherent — even while, at the same time, we can be overwhelmingly confident about certain aspects of reality.
Only in the most trivial sense — namely, that we don’t currently observe anything beyond us. If you can offer some observations we can make for ourselves — “Show me,” as they might say in Missouri — then we’ll happily revise our understanding.
You spectacularly miss the point of poetic naturalism, and commit the one big fallacy in equally spectacular fashion.
An individual coin toss is as irrelevant to the Bell curve as core physics is to human passion, and vice-versa.
We are humans, so we care about the Bell curve, about our passions. The coin tosses that underlie our passions are certainly academically interesting, but we are our passions, not the coin tosses.
One of the academic insights we can gain from a fuller understanding of our coin tosses is that there isn’t some “From Elsewhere” meddling about in our passions; we are self-contained. For better or worse, we’re on our own. Succeed or fail as you will; there are no gods who will judge you. But you will and always do judge you, and you’re not likely to be happy with your own judgement unless you do your best to succeed.
And if you can’t see how this maximizes humanity, you need to re-watch that famous Twilight Zone episode. Go ahead and grant the existence of the gods, even that they dictated the holy texts. As far as you can ever know, “To Serve Man” is actually a cookbook. The Good Shepherd may well protect his flock from the wolves, but every last little lamb is destined for the Shepherd’s stew pot. Just as the sheep would be much better off with sheepism than humanism, humans are much better off with humanism than with theism.
Cheers,
b&