I have a degree in theoretical physics and a gold medal, which is to say I have endured the requisite intellectual beatings. Often the best interpretations of physical theory are unpalatable to the average person. The idea that there is in fact no objective physical reality is the most egregious offender in this regard. However, it is nonetheless the best conclusion that one can draw given strict adherence to what the mathematical formalism of QM provides. There is simply no physical machinery to support an objective reality, period.
Now, that being said, the remarkable part is that the forgoing conclusion does us zero harm. We can still have the logical predictive fiction that an objective reality exists. What staggers the mind is the corollary that no human has ever erected a truth. Moreover, every intelligent species that ever endeavors to ask these questions will find the same non-answer.
Once the notion of objective truth is relinquished, what ontological or epistemic status remains for reasoning itself? Is it to be understood as a pragmatic construct, or as something with deeper necessity beyond empiricism?
For non-relativistic QM, the QM formalism is provable from Bohmian mechanics, an actual particle theory. BM starts from particles have locations the change continuously in time via a guidance equation using the wave function of the universe. One may choose other theories to explain quantum phenomena, but to say "There is simply no physical machinery to support an objective reality, period." is just false, at least in that realm. As for relativistic QFT, there are plausible pathways using Bohmian ideas as well though nothing as definitive as BM has been firmly established.
I would also say that any theory that does not have room to say definitively that I exist is a theory that is obviously contradictory to my experience and is therefore falsified. There has to be room in the theory for at least me. Additionally, I would certainly value much more a theory that has room for the rest of humanity more than one which questions the existence of everyone but me. I am not even sure what the point of a theory would be if it could not account for collaborative science being done.
QM does not deny you existence, it rather denies you a complete objective description of how you exist. Or perhaps it says that your existence is not an objective phenomena.
BM is objective, and indeed deterministic. I'm not exactly sure what you mean by "complete" but it has all the same predictions as other interpretations of QM. It has some odd quirks however, such as explicit non-locality.
I think language does us a disservice here. I'm reminded of Korzybski's work in Science and Sanity. The interpretation of "truth" depends on which level of abstraction you are operating on. "Every statement is true in some sense, false in some sense, and meaningless in some sense". The term "reality" implies a perceiver, and that perceiver is generating "reality" based on their neurological instrument, which has its own biases based on its prior experience and genetics.
No. Subjective reality is what we experience as sentients. There must be an object reality and imho that is the only statement of truth that can be uttered in language, with "language" to be understood in the sense that Werner Hisenberg uses that term.
So I'm with Bohr, Hisenberg on this matter. We can not 'presume' to speak of the Real with capital R. It exists but it can not be 'encompassed'.
No vision can encompass Him, but He encompasses all vision. Indeed, He Is the Most Subtle, the All-Aware! - Qur'an - 6.103
Leave out the quran quote since that is most definitely not what Bohr/Heisenberg/Others mean when they talk about subjectivity/observation/measurement. See my comment here - https://news.ycombinator.com/item?id=45759220
If you want to discuss Philosophical/Ontological/Epistemological concepts of Reality/Truth etc. there are far better models in Hindu/Buddhist scriptures.
Your conclusion rests on the assumption that QM's description of reality represents the ontological truth. And such a 'truth' is not provable. However, as you already mentioned, it doesn't matter as QM provides the strongest epistemological claims, and this is what matters in the end.
I think otherwise. I am precisely saying that QM as a formalism denies ontological truth in the first instance. You have to do something like the BM guy above is embarking on.
I am just a lay person so a lot of the maths is over my head for all of this, but I do try to follow the best I can.
Do you ever ponder that the maths that you try to distill into the “laws of physics” is just too low of a fidelity for such a complicated system?
For example when you capture a gorgeous sunrise/sunset in a photo, and despite you doing every trick under the sun to get a good angle/lighting etc, the photo is never as good as what you experienced in person.
Or maybe you just never experienced the sunrise/sunset shrug.
QM provides the most accurate and verifiable predictions in human history. The follow on from that is that my thoughts can be conveyed to you over a sea of quivering electrons. The one catch is that you must accept that when you are not looking the universe does its evolving in a way that is inimical to your conceptualizations.
A wave is a product, trigonometric functions do not exist.
Gerard hooft was on Curt Jaimungal's youtube channel a while back, I generally agree with him, discrete systems cannot be explained by real numbers, only integers
This is not radical. His thought is clearly in line with a very old and very mainstream philosophical tradition called "idealism," and I was surprised to see this go unmentioned in the article. See: https://plato.stanford.edu/entries/idealism/
> Within modern philosophy there are sometimes taken to be two fundamental conceptions of idealism:
> 1. Something mental (the mind, spirit, reason, will) is the ultimate foundation of all reality, or even exhaustive of reality, and
> 2. although the existence of something independent of the mind is conceded, everything that we can know about this mind-independent “reality” is held to be so permeated by the creative, formative, or constructive activities of the mind (of some kind or other) that all claims to knowledge must be considered, in some sense, to be a form of self-knowledge.
Among mainstream philosophical traditions, idealism is IMO the weakest, as it's inevitably solipsistic. Physicalism has become strongest.
I take issue with the “stronger” characterization. Maybe I have a vocabulary problem. However…
Your own perception of the physical world is, by necessity, solipsistic. Your own experience of the physical world is in your own mind. Without that perception, you can’t say it exists.
We know that it’s possible to have this experience of perception without the physical world, as long as your mind exists. In other words, this could all just be a simulation being dumped into your mind without the physical world as you “know” it existing. Hence, idealism.
Whether one is stronger (or more true?) than the other really doesn’t affect how you function within reality - you’re constrained by what you perceive as the physical world.
Your vocabulary is fine. I think that idealism is necessarily weaker than other ways of viewing the world; it has problems that were repeatedly noted throughout the 20th century in major works by Wittgenstein and Heidegger, among others. (In fact, it can quite fairly be said that most of 20th century philosophy is a reaction to the fuzzy, yet superficially persuasive, idealistic tendencies of the 19th. Analytic philosophy is 100% a reaction to this.)
Per Heidegger, well, the entire notion of "being-in-the-world" is a response to idealism. This is the notion that we first encounter a shared world of use, tasks, and significance (hammering, writing, speaking with others,) not private "ideas." So the world as you experience it isn't constructed within your head alone; the outside is always with you. You're embedded in an objective field -- or, at the limit, a consensus field.
As a general rule, you can't make sense of science and the commons as purely private occurrences. One's theories are often false; one is often genuinely surprised.
Besides, even classical idealists need something "beyond" representation (Kant's thing-in-itself; Schopenhauer's subliminal Will) to make sense of why experience has the structure it does. That is, the idealist view silently re-imports something non-mental to ground the mental.
Of course, we could be Boltzmann brains, dreaming clouds of charged gas in the sky, or we could be controlled by Cartesian Demons... and that is where strong idealism eventually leads... but I think that these views should be disfavored even on empirical grounds, for instance in your continued existence.
Indeed. Science isn't the study of the universe, it's the study of our experience of the universe.
Physics tends to imagine that a mind is a neutral blank screen that represents reality faithfully and accurately. But that's nonsense. It's a process that imposes certain kinds of perceptions.
The conceptual metaphors we use - position, mass, velocity, time, causality - are products of that process, not fundamental representations.
It's possible other minds have unimaginably different experiences based on unimaginably different metaphors.
Some of those might have potential mappings to our models, others might not.
People interested in this subject might enjoy this interview with David Albert [1], as well as this interview with Tim Maudlin [2], who offers a different perspective from Albert. They are both philosophers of physics, or in other words physicists working on the foundations of physics.
I especially like 'Quantum Mechanics and Experience' by David Z Albert (he's got a very peculiar style of writing that I enjoy), and 'Quantum Non-Locality and Relativity' by Tim Maudlin.
Not easy reading, but manageable if you have a physics degree.
Another Ph.D. physicist here. Any popularization of quantum mechanics (or quantum gravity in this case) can quickly degenerate into potentially foolish, or even harmful, metaphysical speculation. Physicists are in the business of finding the best set of mathematical rules that describe "If the conditions A exist, then B happens [with a certain probability]." The frustrating part is that about 100 years ago, quantum mechanics provided a set of rules that didn't have an easy intuitive interpretation (i.e. that quantum mechanics is not both a "real and local" theory.) Yet it is wildly successful for what it does, and the mathematics is crystal clear. (By the way, regular non-relativistic quantum mechanics can be interpreted as having "no reality", no fancy quantum loop gravity needed; see e.g.https://arxiv.org/abs/quant-ph/9609013 - more precisely, only correlations exist.)
Taken to its metaphysical conclusion, though, "there is no objective reality" can lead to harm. So, I guess morality is all a matter of perspective? That can be used to justify anything. We do seem to have an emergent reality (at least the one I am experiencing at the moment) that is held in common - just because the underlying mathematics is hard to interpret doesn't justify "anything goes", or my crazy belief is just as good as your crazy belief.
So although it is fun to think about, don't take "there is no objective reality" too seriously - you still have to go to work, you still have to pay your taxes.
I think the idea of an "external reality that follows certain rules and humans operate in" could itself be a kind of evolutionarily-advantageous belief, even if it's not actually true in a quantum physics sense. In other words, we become capable of science and technology only after assuming there are scientific rules to be found.
There are many concepts like this throughout human history - another one I'm thinking of is the (in the West) monotheistic idea of narrative history/time. By framing time as something that can have a beginning and end, you enable or at least incentivize "progress", and mentally unlock the ability to work toward some idealized future, rather than accepting that time is cyclical and/or without some notion of moving forward.
I like the article. And I applaud any physicist trying to come to grips with our conceptions of reality AND reading up on philosophy. That being said, he's neither the first nor will he be the last, nor is "perpectivism" in epistomology a new thing. I like, however, how he is throwing in several streams (I saw James, Nietzsche, Kuhn, and even Rorty and Wittgenstein II) of thought, centered on Kant's ideas of the noumenon and its inaccessibility. I don't think I agree with him, though ;)
If I had to label him, I'd say he is mostly an anti-realist.
Mario Bunge was another physicist who deeply engaged with philosophy (he taught philosophy at McGill University). Interestingly, the conclusions he arrived at were quite the opposite.
> There is no objective reality, according to Rovelli — only perspectives. “This is very radical, because you can no longer say, ‘This is a list of things in the world, and this is how they are.’"
Perfectly in line with his political views, when he's a guest on the Italian TV's, or on social media he spend so much time defending the reasons of the Russian in the Ukrainian invasion. With hosts that often asks physics and political questions in the same set, as if his way of looking at reality gives him any ground truth. I'm wondering how much his physics and political views overlap. Such a delusion for me as Italian, I stopped reading his books for this reason and because at some point, after the wonder effect of reading about quantum worlds, I was left with the sensation that I read a lot and nothing at the same
time
The thing with idealists in the philosophical sense is that they're typically not very well grounded in reality. Not saying it's always drugs/psychotic breaks/deep meditation, but often it is. Even more so with the panpsychists.
As former physics student, a lot of ego and little physics IMHO.
Theoretical physics is pointless without experimental tests. Personally, I prefer physicists spending more time in the lab or in classroom than on mass media
How do these quantum + gravity loops/patches evolve continuously w/o time? The more I learn about theoretical physics & physicists the more I'm convinced these people are basically idiot savants.
Not sure about this specific theory, but I imagine it's similar to Wolfram's Digital Physics project, where you have "ticks" that apply the rules to eems, and then out of the maze of rule applications we somehow get time as we perceive it.
I am willing to grant that time is indeed an illusion b/c we do not have perfect perception of reality but it seems like all these new developments are squirreling time away into another part of the theory by calling it something else like "dynamics", "rule application", "evolution", etc. The physically relevant relations happen one way or another & whatever they're calling the deltas between the new primitive states & their evolution is still referring to some coordinate (whether implicit or not) that is essentially the same thing as time.
Moreover, it's pretty obvious that when they're describing the theory they can not avoid evoking temporal language & metaphors so it's difficult to take them seriously when even they can't avoid describing what's going on w/o referring to time.
My naive way to think about a reality without time is that all the possibile states of reality are already there, all together. The rules are about how to move from one state to another one, like water flowing on the side of a mountain.
Those rules might be be deterministic or there may be a roll of a dice. Then what we perceive as time is the sequence of states, the memory of previous states. No ticks are needed: there might be no central clock like in CPUs, each part of reality might apply those rules continously and move the global state from one state to another one.
But this is not physics as we are doing it now, it's presocratic philosophy. They got the idea of atoms right among a number of ones that turned on wrong.
There's no motion in what you've described. You're describing a crystal or maybe a hologram. David Bohm is the main physicist I know about who has written on this topic but I'm sure there are a few others by now as well who are taking holographic principles seriously.
I'm not a physicist either but this stuff isn't magic. Most of the mathematics used by physicists isn't complicated if you've managed to get past calculus.
If you read a lot of analytical philosophy & meta-mathematics literature you'll notice it's not unique at all. That's how I learned the short-hand conventions.
at a macroscopic level obviously what they describe must look like "time" to match what we see
but time ticking because of some dynamic interaction mechanism between some things (like a mechanical clock) is very different than some fundamental/abstract/irreducible "time" which just is (like in einstein)
Seriously, it would interest me when they enable the creation of something akin to a warp drive.
- First, because it would be a way to test these hypotheses
- Second, because it would dramatically expand humanity's playground, even if it's only in the solar system in the first step.
- Third, because building a Warp drive would be good for the economy. Currently, we have no equivalent to the space race. We have AI, but there are doubts that it will enable more than incremental steps.
Baader-Meinhof complex in action: I have _just_ ordered a book of Rovelli's (Reality is Not What It Seems - https://en.wikipedia.org/wiki/Reality_Is_Not_What_It_Seems), it should be in my hands by the end of the week. I am fascinated by the ongoing work in quantum gravity, it's tantalising by its nature.
This is a great interview and I must say I like the man a lot more than I did before. He has articulated something here that I have long felt: that it is as important in politics as it is in philosophy or theoretical physics to be able to state one's assumptions, to suspend one's assumptions for the sake of argument and to drop/change one's assumptions in the face of evidence.
I feel like this is a vital skill that we, as a society, need now maybe more than ever, in literally any field in which there is any meaningful concept of "correct" (which I think is most fields). I also think it's a skill you basically learn at university - and that that is a problem. I don't know what an approach to cultivating it more widely would look like.
The core idea of relational quantum mechanics is that when we talk about an object — be it an atom, a person or a galaxy — we are never just referring to the system alone. Rather, we are always referring to the interactions between this system and something else. We can only describe — and in fact understand — a thing as it relates to ourselves, or to our measuring devices.
Lee Smolin has gone down a different track but with similar spirit of sorts. Carlo poked fun at Lee for all the work they've done together despite disagreeing on so much in his recent talk[1] at Lee's Fest[2].
Smolin has named his approach the Causal Theory of Views, in which he postulates that spacetime emerges from events, ie relational interactions. This[3] interview, which is a few years old now, contains a decent high-level explanation. The idea that kinda overlaps with Rovelli he explains like this:
The theory that I've been looking for would take advantage of the fact that the notion of locality and nonlocality is key to understanding quantum mechanics, and then try to understand that with the lens of the unification of quantum physics with space and time, which is quantum gravity.
In both approaches, there's a principle, which is the idea of relational physics—that the degrees of freedom, the properties of whatever it is that's dynamical that you're studying, arises from dynamical relationships with other degrees of freedom.
In other words, you don't have absolute space, you don't have particles that occupy points or follow paths or trajectories in absolute space. You have many particles which, between them, allow you to define relative motion.
Lee has given several talks[4] at PIRSA since that interview with more details as he's developed his idea.
So while both go hard on the relational aspect, they disagree on some fundamental things. Rovelli thinks time is an illusion, but in Lee's CTV time is real and space is the illusion (emergent).
Who knows if it'll pan out or be a dead end, but since the quantum physics community has been headbutting the fundamental issues with little progress for so many decades, it seems prudent to try some bold approaches.
I'm not a physicist by any means but I was just thinking something similar only a few minutes ago... that humans (or anything) ageing probably only exists as a function of the passage of time, but if all matter stopped moving, even in an isolated area, there is seemingly no longer a passage of time there. So maybe time itself only exists insofar as our ability to measure relative changes to matter.
A crazy thought I had in my sleep: What if dark matter only exists as a random noise generator to keep the simulation from halting? /s
> My intuition is that the overall flow of time really could be like the rotation of the sky every day. It’s a majestic, immense phenomenon, but it’s actually an illusion. This is a totally perspectival understanding of the second law of thermodynamics. It’s real in the same sense that the rotating sky is real, but it’s real only with respect to us.
And later:
> Our community has wasted a lot of time searching after speculative ideas. What we need instead is to digest the knowledge we already have. And to do that, we need philosophy. Philosophers help us not to find the right answers to given questions, but to find the right questions to better conceptualize reality.
I think it’s odd that a physicists proposes a new theory without suggesting experiments that could falsify the theory.
That second quote hits hard. Physics got so good at answering questions that people forgot to check if they were asking the right ones. Same thing happens in tech - we're really good at optimizing for metrics, terrible at asking if those metrics matter.
I love Rovelli, but to me he’s just another proof that if you look for too long into the quantum abyss, the abyss is gonna eventually look back at you…
Most folks don't understand what Physicists mean when they say "Reality doesn't exist at the Quantum level". Words like "Reality", "Illusion" etc. mean quite different things when applied at quantum level vs. classical-macro level.
The best book to get a grasp on the above is Werner Heisenberg's classic Physics and Philosophy: The Revolution in Modern Science. The introduction by Paul Davies itself is worth the price of the book since it highlights the main issues quite clearly.
At the fundamental level quantum systems have an inherent indeterminism (as a consequence of the famous uncertainty principle) which is what we find hard to grasp. It does not mean total anarchy but that you can only calculate relative probabilities of the alternatives in the answer set i.e. it is a statistical theory. Thus it can make definite predictions about sets of identical systems but generally cannot say anything definite about a specific individual system.
For example, an electron doesn't exist as a single thing occupying a specific trajectory around the nucleus. It only exists as a set of potentialities occupying an area of space viz. the so called electron shell. Only when a measurement is made does a electron-with-position or electron-with-momentum
can be said to come into existence (since before the measurement there are only probabilities and you cannot measure both position and momentum sharply simultaneously). It is in this sense that the Reality of an electron is said to only exist in the Measurement/Observation and cannot be said to exist otherwise.
The other side of the coin is that, Modern Neuroscience tells us that the Brain itself is wired to Construct Reality from incomplete data and we seek/construct patterns where there are none. See for example Cordelia Fine's A Mind of Its Own: How Your Brain Distorts and Deceives and watch this Ted talk by Susana Martinez-Conde Reality is made of illusions—and we need them - https://www.youtube.com/watch?v=FzDw07RqCSs
I have a degree in theoretical physics and a gold medal, which is to say I have endured the requisite intellectual beatings. Often the best interpretations of physical theory are unpalatable to the average person. The idea that there is in fact no objective physical reality is the most egregious offender in this regard. However, it is nonetheless the best conclusion that one can draw given strict adherence to what the mathematical formalism of QM provides. There is simply no physical machinery to support an objective reality, period.
Now, that being said, the remarkable part is that the forgoing conclusion does us zero harm. We can still have the logical predictive fiction that an objective reality exists. What staggers the mind is the corollary that no human has ever erected a truth. Moreover, every intelligent species that ever endeavors to ask these questions will find the same non-answer.
Once the notion of objective truth is relinquished, what ontological or epistemic status remains for reasoning itself? Is it to be understood as a pragmatic construct, or as something with deeper necessity beyond empiricism?
For non-relativistic QM, the QM formalism is provable from Bohmian mechanics, an actual particle theory. BM starts from particles have locations the change continuously in time via a guidance equation using the wave function of the universe. One may choose other theories to explain quantum phenomena, but to say "There is simply no physical machinery to support an objective reality, period." is just false, at least in that realm. As for relativistic QFT, there are plausible pathways using Bohmian ideas as well though nothing as definitive as BM has been firmly established.
I would also say that any theory that does not have room to say definitively that I exist is a theory that is obviously contradictory to my experience and is therefore falsified. There has to be room in the theory for at least me. Additionally, I would certainly value much more a theory that has room for the rest of humanity more than one which questions the existence of everyone but me. I am not even sure what the point of a theory would be if it could not account for collaborative science being done.
QM does not deny you existence, it rather denies you a complete objective description of how you exist. Or perhaps it says that your existence is not an objective phenomena.
BM is objective, and indeed deterministic. I'm not exactly sure what you mean by "complete" but it has all the same predictions as other interpretations of QM. It has some odd quirks however, such as explicit non-locality.
I think language does us a disservice here. I'm reminded of Korzybski's work in Science and Sanity. The interpretation of "truth" depends on which level of abstraction you are operating on. "Every statement is true in some sense, false in some sense, and meaningless in some sense". The term "reality" implies a perceiver, and that perceiver is generating "reality" based on their neurological instrument, which has its own biases based on its prior experience and genetics.
I agree that language other than math fails us here. Nevertheless, I humbly try to convey thoughts that occur in me with these tools.
> The term "reality" implies a perceiver
No. Subjective reality is what we experience as sentients. There must be an object reality and imho that is the only statement of truth that can be uttered in language, with "language" to be understood in the sense that Werner Hisenberg uses that term.
So I'm with Bohr, Hisenberg on this matter. We can not 'presume' to speak of the Real with capital R. It exists but it can not be 'encompassed'.
No vision can encompass Him, but He encompasses all vision. Indeed, He Is the Most Subtle, the All-Aware! - Qur'an - 6.103
Leave out the quran quote since that is most definitely not what Bohr/Heisenberg/Others mean when they talk about subjectivity/observation/measurement. See my comment here - https://news.ycombinator.com/item?id=45759220
If you want to discuss Philosophical/Ontological/Epistemological concepts of Reality/Truth etc. there are far better models in Hindu/Buddhist scriptures.
Your conclusion rests on the assumption that QM's description of reality represents the ontological truth. And such a 'truth' is not provable. However, as you already mentioned, it doesn't matter as QM provides the strongest epistemological claims, and this is what matters in the end.
I think otherwise. I am precisely saying that QM as a formalism denies ontological truth in the first instance. You have to do something like the BM guy above is embarking on.
I am just a lay person so a lot of the maths is over my head for all of this, but I do try to follow the best I can.
Do you ever ponder that the maths that you try to distill into the “laws of physics” is just too low of a fidelity for such a complicated system?
For example when you capture a gorgeous sunrise/sunset in a photo, and despite you doing every trick under the sun to get a good angle/lighting etc, the photo is never as good as what you experienced in person.
Or maybe you just never experienced the sunrise/sunset shrug.
QM provides the most accurate and verifiable predictions in human history. The follow on from that is that my thoughts can be conveyed to you over a sea of quivering electrons. The one catch is that you must accept that when you are not looking the universe does its evolving in a way that is inimical to your conceptualizations.
You have beautiful way of writing. Do you have a blog?
Thank you so much, I don't.
Thank you for trying.
What were you hoping for?
I apologise as I replied in a shirty manner and deleted as I thought better of it.
I don’t think we’ll be able to really discuss the matter so have a good night!
The idea is that there is no "complicated system", or at least that you are not permitted to concieve of one without describing it in physical detail.
> is just too low of a fidelity for such a complicated system?
I think you're asking questions that some are afraid to ask.
It appears to me that some people have become accustomed to working with approximations, and have accepted the map for the terrain.
Fundamentally, I don't see how you can use continuous math to explain a discrete system.
"It appears to me that some people have become accustomed to working with approximations, and have accepted the map for the terrain."
No, here we are discussing the formalism without approximations associated with an instance of its approximate application.
And QM says "The map is the terrain".
QM is many things
You might want to be a little more specific, and rely less on approximations.
I am aware of what the Copenhagen interpretation states, thanks
To what approximations do you refer?
Here we discard Copenhagen and move forward.
Take your pick
Schrodinger/Dirac/Feynman.
A wave is a product, trigonometric functions do not exist.
Gerard hooft was on Curt Jaimungal's youtube channel a while back, I generally agree with him, discrete systems cannot be explained by real numbers, only integers
> What staggers the mind is the corollary that no human has ever erected a truth.
Hell, you don't need a physics degree for this, nor even QM, just a robust grasp of the limits of empiricism. Hume connected the dots centuries ago.
I see this as decidedly non-Humean. Why be Humean anyway?
This is not radical. His thought is clearly in line with a very old and very mainstream philosophical tradition called "idealism," and I was surprised to see this go unmentioned in the article. See: https://plato.stanford.edu/entries/idealism/
> Within modern philosophy there are sometimes taken to be two fundamental conceptions of idealism:
> 1. Something mental (the mind, spirit, reason, will) is the ultimate foundation of all reality, or even exhaustive of reality, and
> 2. although the existence of something independent of the mind is conceded, everything that we can know about this mind-independent “reality” is held to be so permeated by the creative, formative, or constructive activities of the mind (of some kind or other) that all claims to knowledge must be considered, in some sense, to be a form of self-knowledge.
Among mainstream philosophical traditions, idealism is IMO the weakest, as it's inevitably solipsistic. Physicalism has become strongest.
I take issue with the “stronger” characterization. Maybe I have a vocabulary problem. However…
Your own perception of the physical world is, by necessity, solipsistic. Your own experience of the physical world is in your own mind. Without that perception, you can’t say it exists.
We know that it’s possible to have this experience of perception without the physical world, as long as your mind exists. In other words, this could all just be a simulation being dumped into your mind without the physical world as you “know” it existing. Hence, idealism.
Whether one is stronger (or more true?) than the other really doesn’t affect how you function within reality - you’re constrained by what you perceive as the physical world.
Your vocabulary is fine. I think that idealism is necessarily weaker than other ways of viewing the world; it has problems that were repeatedly noted throughout the 20th century in major works by Wittgenstein and Heidegger, among others. (In fact, it can quite fairly be said that most of 20th century philosophy is a reaction to the fuzzy, yet superficially persuasive, idealistic tendencies of the 19th. Analytic philosophy is 100% a reaction to this.)
Per the Wittgenstein, you have, e.g., the "private language" problem: https://plato.stanford.edu/entries/private-language/
Per Heidegger, well, the entire notion of "being-in-the-world" is a response to idealism. This is the notion that we first encounter a shared world of use, tasks, and significance (hammering, writing, speaking with others,) not private "ideas." So the world as you experience it isn't constructed within your head alone; the outside is always with you. You're embedded in an objective field -- or, at the limit, a consensus field.
As a general rule, you can't make sense of science and the commons as purely private occurrences. One's theories are often false; one is often genuinely surprised.
Besides, even classical idealists need something "beyond" representation (Kant's thing-in-itself; Schopenhauer's subliminal Will) to make sense of why experience has the structure it does. That is, the idealist view silently re-imports something non-mental to ground the mental.
Of course, we could be Boltzmann brains, dreaming clouds of charged gas in the sky, or we could be controlled by Cartesian Demons... and that is where strong idealism eventually leads... but I think that these views should be disfavored even on empirical grounds, for instance in your continued existence.
Indeed. Science isn't the study of the universe, it's the study of our experience of the universe.
Physics tends to imagine that a mind is a neutral blank screen that represents reality faithfully and accurately. But that's nonsense. It's a process that imposes certain kinds of perceptions.
The conceptual metaphors we use - position, mass, velocity, time, causality - are products of that process, not fundamental representations.
It's possible other minds have unimaginably different experiences based on unimaginably different metaphors.
Some of those might have potential mappings to our models, others might not.
People interested in this subject might enjoy this interview with David Albert [1], as well as this interview with Tim Maudlin [2], who offers a different perspective from Albert. They are both philosophers of physics, or in other words physicists working on the foundations of physics.
[1] https://www.youtube.com/watch?v=JR2sMeXLuLw [2] https://www.youtube.com/watch?v=3riyyEmWwoY
They have written some good books too.
I especially like 'Quantum Mechanics and Experience' by David Z Albert (he's got a very peculiar style of writing that I enjoy), and 'Quantum Non-Locality and Relativity' by Tim Maudlin.
Not easy reading, but manageable if you have a physics degree.
Thank you for the links :)
Another Ph.D. physicist here. Any popularization of quantum mechanics (or quantum gravity in this case) can quickly degenerate into potentially foolish, or even harmful, metaphysical speculation. Physicists are in the business of finding the best set of mathematical rules that describe "If the conditions A exist, then B happens [with a certain probability]." The frustrating part is that about 100 years ago, quantum mechanics provided a set of rules that didn't have an easy intuitive interpretation (i.e. that quantum mechanics is not both a "real and local" theory.) Yet it is wildly successful for what it does, and the mathematics is crystal clear. (By the way, regular non-relativistic quantum mechanics can be interpreted as having "no reality", no fancy quantum loop gravity needed; see e.g.https://arxiv.org/abs/quant-ph/9609013 - more precisely, only correlations exist.)
Taken to its metaphysical conclusion, though, "there is no objective reality" can lead to harm. So, I guess morality is all a matter of perspective? That can be used to justify anything. We do seem to have an emergent reality (at least the one I am experiencing at the moment) that is held in common - just because the underlying mathematics is hard to interpret doesn't justify "anything goes", or my crazy belief is just as good as your crazy belief.
So although it is fun to think about, don't take "there is no objective reality" too seriously - you still have to go to work, you still have to pay your taxes.
I think the idea of an "external reality that follows certain rules and humans operate in" could itself be a kind of evolutionarily-advantageous belief, even if it's not actually true in a quantum physics sense. In other words, we become capable of science and technology only after assuming there are scientific rules to be found.
There are many concepts like this throughout human history - another one I'm thinking of is the (in the West) monotheistic idea of narrative history/time. By framing time as something that can have a beginning and end, you enable or at least incentivize "progress", and mentally unlock the ability to work toward some idealized future, rather than accepting that time is cyclical and/or without some notion of moving forward.
I dare say the phenomenon is real and our understanding is lacking.
I like the article. And I applaud any physicist trying to come to grips with our conceptions of reality AND reading up on philosophy. That being said, he's neither the first nor will he be the last, nor is "perpectivism" in epistomology a new thing. I like, however, how he is throwing in several streams (I saw James, Nietzsche, Kuhn, and even Rorty and Wittgenstein II) of thought, centered on Kant's ideas of the noumenon and its inaccessibility. I don't think I agree with him, though ;)
If I had to label him, I'd say he is mostly an anti-realist.
Mario Bunge was another physicist who deeply engaged with philosophy (he taught philosophy at McGill University). Interestingly, the conclusions he arrived at were quite the opposite.
> There is no objective reality, according to Rovelli — only perspectives. “This is very radical, because you can no longer say, ‘This is a list of things in the world, and this is how they are.’"
Perfectly in line with his political views, when he's a guest on the Italian TV's, or on social media he spend so much time defending the reasons of the Russian in the Ukrainian invasion. With hosts that often asks physics and political questions in the same set, as if his way of looking at reality gives him any ground truth. I'm wondering how much his physics and political views overlap. Such a delusion for me as Italian, I stopped reading his books for this reason and because at some point, after the wonder effect of reading about quantum worlds, I was left with the sensation that I read a lot and nothing at the same time
The thing with idealists in the philosophical sense is that they're typically not very well grounded in reality. Not saying it's always drugs/psychotic breaks/deep meditation, but often it is. Even more so with the panpsychists.
As former physics student, a lot of ego and little physics IMHO. Theoretical physics is pointless without experimental tests. Personally, I prefer physicists spending more time in the lab or in classroom than on mass media
Some degree of engagement with popular opinion and culture might be needed to keep on getting money for the experiments and grants for the students.
But I take the point you are making.
I haven’t heard about his views on Russia but that’s worth looking into since I also have his books.
Just a quick nitpick as a fellow Italian: “delusion” (“illusione”) is a false friend of “delusione.” Maybe you meant “disappointment”!
thanks for the false friend! Let me share, one the many, critic articles to rovelli https://www.ilfoglio.it/russia-ucraina/2023/04/11/news/caro-...
How do these quantum + gravity loops/patches evolve continuously w/o time? The more I learn about theoretical physics & physicists the more I'm convinced these people are basically idiot savants.
Not sure about this specific theory, but I imagine it's similar to Wolfram's Digital Physics project, where you have "ticks" that apply the rules to eems, and then out of the maze of rule applications we somehow get time as we perceive it.
I am willing to grant that time is indeed an illusion b/c we do not have perfect perception of reality but it seems like all these new developments are squirreling time away into another part of the theory by calling it something else like "dynamics", "rule application", "evolution", etc. The physically relevant relations happen one way or another & whatever they're calling the deltas between the new primitive states & their evolution is still referring to some coordinate (whether implicit or not) that is essentially the same thing as time.
Moreover, it's pretty obvious that when they're describing the theory they can not avoid evoking temporal language & metaphors so it's difficult to take them seriously when even they can't avoid describing what's going on w/o referring to time.
My naive way to think about a reality without time is that all the possibile states of reality are already there, all together. The rules are about how to move from one state to another one, like water flowing on the side of a mountain.
Those rules might be be deterministic or there may be a roll of a dice. Then what we perceive as time is the sequence of states, the memory of previous states. No ticks are needed: there might be no central clock like in CPUs, each part of reality might apply those rules continously and move the global state from one state to another one.
But this is not physics as we are doing it now, it's presocratic philosophy. They got the idea of atoms right among a number of ones that turned on wrong.
There's no motion in what you've described. You're describing a crystal or maybe a hologram. David Bohm is the main physicist I know about who has written on this topic but I'm sure there are a few others by now as well who are taking holographic principles seriously.
Not a physicist but this echoes my feelings when people talk about time as an emergent phenomenon.
I'm not a physicist either but this stuff isn't magic. Most of the mathematics used by physicists isn't complicated if you've managed to get past calculus.
Very off-topic but use of "b/c" and "w/o" in all your posts makes you stand out quite a bit. And the particular use of "&", as well.
If you read a lot of analytical philosophy & meta-mathematics literature you'll notice it's not unique at all. That's how I learned the short-hand conventions.
at a macroscopic level obviously what they describe must look like "time" to match what we see
but time ticking because of some dynamic interaction mechanism between some things (like a mechanical clock) is very different than some fundamental/abstract/irreducible "time" which just is (like in einstein)
A person proposing to stop or limit military aid to Ukraine "for peace" has decidedly radical view on reality, that's for sure.
Carlo Rovelli: 'Time Is an Illusion' - https://www.youtube.com/watch?v=PuLaUYQFIwg
Related. Others?
Carlo Rovelli on challenging our common-sense notion of time - https://news.ycombinator.com/item?id=17893865 - Sept 2018 (74 comments)
Carlo Rovelli on the ‘greatest remaining mystery’: The nature of time - https://news.ycombinator.com/item?id=17376437 - June 2018 (143 comments)
For a counterpoint see:
https://arxiv.org/pdf/2105.13338
And my own personal take on it:
https://blog.rongarret.info/2014/10/parallel-universes-and-a...
https://arxiv.org/abs/2105.13338
Could you please cite the abstract pages instead of the pdf.
The pdf is linked off the abstract page anyway, in case the reader wants to download that after reading the abstract.
The abstract pages usually have other bibliographic goodies that can be easily accessed.
Seriously, it would interest me when they enable the creation of something akin to a warp drive.
- First, because it would be a way to test these hypotheses
- Second, because it would dramatically expand humanity's playground, even if it's only in the solar system in the first step.
- Third, because building a Warp drive would be good for the economy. Currently, we have no equivalent to the space race. We have AI, but there are doubts that it will enable more than incremental steps.
What hypothesis would be tested by a warp drive?
All these theories question the nature of space, time, and matter:
- Loop Quantum Gravity
https://en.wikipedia.org/wiki/Loop_quantum_gravity
- Causal Set Theory
https://en.wikipedia.org/wiki/Causal_sets
- AdS/CFT & Tensor Networks
https://qspace.fqxi.org/videos/121/a-tensor-network-approach...
- Relational Quantum Mechanics
The one discussed here
- “It from Qubit”
https://www.scientificamerican.com/article/tangled-up-in-spa...
- Thermodynamic Gravity
https://en.wikipedia.org/wiki/Entropic_gravity
- Noncommutative Geometry
https://en.wikipedia.org/wiki/Noncommutative_quantum_field_t...
Baader-Meinhof complex in action: I have _just_ ordered a book of Rovelli's (Reality is Not What It Seems - https://en.wikipedia.org/wiki/Reality_Is_Not_What_It_Seems), it should be in my hands by the end of the week. I am fascinated by the ongoing work in quantum gravity, it's tantalising by its nature.
This is a great interview and I must say I like the man a lot more than I did before. He has articulated something here that I have long felt: that it is as important in politics as it is in philosophy or theoretical physics to be able to state one's assumptions, to suspend one's assumptions for the sake of argument and to drop/change one's assumptions in the face of evidence.
I feel like this is a vital skill that we, as a society, need now maybe more than ever, in literally any field in which there is any meaningful concept of "correct" (which I think is most fields). I also think it's a skill you basically learn at university - and that that is a problem. I don't know what an approach to cultivating it more widely would look like.
The core idea of relational quantum mechanics is that when we talk about an object — be it an atom, a person or a galaxy — we are never just referring to the system alone. Rather, we are always referring to the interactions between this system and something else. We can only describe — and in fact understand — a thing as it relates to ourselves, or to our measuring devices.
Lee Smolin has gone down a different track but with similar spirit of sorts. Carlo poked fun at Lee for all the work they've done together despite disagreeing on so much in his recent talk[1] at Lee's Fest[2].
Smolin has named his approach the Causal Theory of Views, in which he postulates that spacetime emerges from events, ie relational interactions. This[3] interview, which is a few years old now, contains a decent high-level explanation. The idea that kinda overlaps with Rovelli he explains like this:
The theory that I've been looking for would take advantage of the fact that the notion of locality and nonlocality is key to understanding quantum mechanics, and then try to understand that with the lens of the unification of quantum physics with space and time, which is quantum gravity.
In both approaches, there's a principle, which is the idea of relational physics—that the degrees of freedom, the properties of whatever it is that's dynamical that you're studying, arises from dynamical relationships with other degrees of freedom.
In other words, you don't have absolute space, you don't have particles that occupy points or follow paths or trajectories in absolute space. You have many particles which, between them, allow you to define relative motion.
Lee has given several talks[4] at PIRSA since that interview with more details as he's developed his idea.
So while both go hard on the relational aspect, they disagree on some fundamental things. Rovelli thinks time is an illusion, but in Lee's CTV time is real and space is the illusion (emergent).
Who knows if it'll pan out or be a dead end, but since the quantum physics community has been headbutting the fundamental issues with little progress for so many decades, it seems prudent to try some bold approaches.
[1]: https://pirsa.org/25060030
[2]: https://pirsa.org/c25023
[3]: https://www.edge.org/conversation/lee_smolin-the-causal-theo...
[4]: https://pirsa.org/speaker/lee-smolin
I'm not a physicist by any means but I was just thinking something similar only a few minutes ago... that humans (or anything) ageing probably only exists as a function of the passage of time, but if all matter stopped moving, even in an isolated area, there is seemingly no longer a passage of time there. So maybe time itself only exists insofar as our ability to measure relative changes to matter.
A crazy thought I had in my sleep: What if dark matter only exists as a random noise generator to keep the simulation from halting? /s
My brain is weird.
> My intuition is that the overall flow of time really could be like the rotation of the sky every day. It’s a majestic, immense phenomenon, but it’s actually an illusion. This is a totally perspectival understanding of the second law of thermodynamics. It’s real in the same sense that the rotating sky is real, but it’s real only with respect to us.
And later:
> Our community has wasted a lot of time searching after speculative ideas. What we need instead is to digest the knowledge we already have. And to do that, we need philosophy. Philosophers help us not to find the right answers to given questions, but to find the right questions to better conceptualize reality.
I think it’s odd that a physicists proposes a new theory without suggesting experiments that could falsify the theory.
That second quote hits hard. Physics got so good at answering questions that people forgot to check if they were asking the right ones. Same thing happens in tech - we're really good at optimizing for metrics, terrible at asking if those metrics matter.
This falls in line with the absolute rarity of questioning your own assumptions. In my experience few do.
The amount of people looking outward only is too damn high, as the saying goes.
pretty much all experiments that could have been done were done
and you can rearrange equations to make them better fit together without needing new experiments
I love Rovelli, but to me he’s just another proof that if you look for too long into the quantum abyss, the abyss is gonna eventually look back at you…
Most folks don't understand what Physicists mean when they say "Reality doesn't exist at the Quantum level". Words like "Reality", "Illusion" etc. mean quite different things when applied at quantum level vs. classical-macro level.
The best book to get a grasp on the above is Werner Heisenberg's classic Physics and Philosophy: The Revolution in Modern Science. The introduction by Paul Davies itself is worth the price of the book since it highlights the main issues quite clearly.
At the fundamental level quantum systems have an inherent indeterminism (as a consequence of the famous uncertainty principle) which is what we find hard to grasp. It does not mean total anarchy but that you can only calculate relative probabilities of the alternatives in the answer set i.e. it is a statistical theory. Thus it can make definite predictions about sets of identical systems but generally cannot say anything definite about a specific individual system.
For example, an electron doesn't exist as a single thing occupying a specific trajectory around the nucleus. It only exists as a set of potentialities occupying an area of space viz. the so called electron shell. Only when a measurement is made does a electron-with-position or electron-with-momentum can be said to come into existence (since before the measurement there are only probabilities and you cannot measure both position and momentum sharply simultaneously). It is in this sense that the Reality of an electron is said to only exist in the Measurement/Observation and cannot be said to exist otherwise.
The other side of the coin is that, Modern Neuroscience tells us that the Brain itself is wired to Construct Reality from incomplete data and we seek/construct patterns where there are none. See for example Cordelia Fine's A Mind of Its Own: How Your Brain Distorts and Deceives and watch this Ted talk by Susana Martinez-Conde Reality is made of illusions—and we need them - https://www.youtube.com/watch?v=FzDw07RqCSs