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.
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)
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.
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
[3]: https://www.edge.org/conversation/lee_smolin-the-causal-theo...
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.
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.
The amount of people looking outward only is too damn high, as the saying goes.
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)
https://arxiv.org/pdf/2105.13338
And my own personal take on it:
https://blog.rongarret.info/2014/10/parallel-universes-and-a...
vismit2000•1h ago