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.

> 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.

[1] https://www.youtube.com/watch?v=JR2sMeXLuLw [2] https://www.youtube.com/watch?v=3riyyEmWwoY

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.

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

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.

If I had to label him, I'd say he is mostly an anti-realist.

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

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)

- 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.

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

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.

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.

He still obviously believes in some sort of underlying "reality" in spite of his claims to the contrary.

The wavefunction evolves as if it were a single, global, observer-independent object.Between interactions, nothing “happens” to it. It doesn’t care who’s looking. It just evolves — deterministically, coherently, globally.

This is not a “perspective.” This is a God’s-eye view — the very thing Rovelli says doesn’t exist. If there were no underlying system, how do you compute interference?

He is in practice unable to accept the parsimonious and experimentally supported idea that very simply: regularity is only achieved at the price of generality.

Rovelli says it, but lives in denial. He cannot accept it because it would force him to abandon the global wavefunction — the silent god of his physics.

Huh? But that's an argument for philosophy, not against it. Peacocks were left alone and look where their evolution ended up, such misdirected result won't be beneficial for science.