Join the discussion
Write your take first — we'll ask for email only when you're ready to publish.
- Hacker News
- Time is not an illusion. It can be experimentally verified. There is a flow in a certain direction. Carlo is saying that time is not absolute, every point on the space is a clock, essentially trying to convey the core concepts of special relativity with engaging interaction.
- Genuinely curious - what experiment can be used to verify the existence of time?by jacksavage
- 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…
- And wink...by Iwan-Zotow
- 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)
by tomhow - 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...
by lisper - > 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
by hollowturtle - 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”!
by terabytest - 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 mediaby y0ned4
- 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.by dhoe
- 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.
by Propelloni - 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.by Antibabelic
- 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.
- Haha, the author observes that basis transformations don't change the state and concludes that there's no absolute state of being.by GoblinSlayer
- You, too, are practicing and advocating for a philosophy here.
Also, the lack of objectivity in the universe doesn't necessarily mean that nihilism is the ONLY way to go. Existentialism, for example, doesn't accept an objective reality either, and folks have found ways to make morality (and even religious faith) fully compatible within that framework.
Obviously, it's not good to delve into metaphysical speculation, as it often clearly leads to junk conclusions written by people who don't have the credentials to account for what the actual science (OR the actual philosophy) says.
But I do wonder what it would be like if modern physicists were more willing to pair up with modern philosophers once in awhile. I would very much love to see a collaboration between the two fields to explore what a subjective universe really MEANS to us as both a species and as moral beings in that universe.
I, very much, would love to see what some of these implications are, as written out by the folks who actually understand the science. Even if there's no true consensus among them, just learning what the different possibilities might be could be very enlightening.
by dentemple - > 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]."
Physics can't claim domain over the study of reality and then say that reality can only be studied using mathematical rules. You can either say physics is the study of mathematical physicalism and stick to your mathematical rules, or you can say physics is the study of reality and be open to alternative ideas outside of mathematics to describe reality. Otherwise you're just precluding the conclusion of what you're supposed to be studying, that reality can be described by mathematical rules.
> Taken to its metaphysical conclusion, though, "there is no objective reality" can lead to harm.
So we should hide reality under a rug if it could possibly lead to harm? The truth is the truth, your objective as a scientist should be to follow the evidence not police morality. History shows that the truth tends to lead towards a better world anyway. I'm sure the Church was afraid of the decay of morality from atheists if they learned that God doesn't keep the planets in motion.
by an0malous - 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
by rramadass - 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.
by keiferski - I dare say the phenomenon is real and our understanding is lacking.by grebc
- Carlo Rovelli: 'Time Is an Illusion' - https://www.youtube.com/watch?v=PuLaUYQFIwgby vismit2000
- 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
by knubie - Thank you for the links :)by grebc
- 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.
by Luc - 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.
by A_D_E_P_T - 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.
- 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.
by d4rkn0d3z - Donald Hoffman, Bernardo Kastrup and other idealists have been saying this for years
https://youtu.be/yqOVu263OSk?si=M3fcLbJneZ0S5Jpq
Adivita Vedanta, Buddhism, mystics and perennial philosophers have been saying this for centuries
https://youtu.be/cwcft4auszA?si=1vYsny6jZb--IE_0
Wolfram is also taking in the same vein but in a different approach
https://youtu.be/8SD9WgPCZ28?si=t8XvVfJV8qi-K_0q
Ie something is up and spacetime is NOT fundamental
by AIorNot - 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.by omnee
- 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.
by jostylr - 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.
by grebc