> Mutability is not just how "the metal" works, it's also how the rest of the world works.
This is actually false. A bit hand wavy here, but the world does not truly exist of discreet objects changing state. That's how we choose to model it, and it's useful, but it's not the "truth" of the world / universe.
A few simple examples - viewed at the quantum level, protons, neutrons, electrons aren't physical objects that "exist" in a unique place at a point in time. Now i'm not saying an imperative model is wrong because of quantum mechanics, but am merely illustrating that we chose to model the world as objects with changing states because it's useful, not because it's accurate or the truth.
The ship of Theseus is another examples. There really is no paradox here as there was never a "ship" to begin with. We just chose to model that particularly assembly of particles as an entity/object known as a ship, and gave it "state" that persists over time. But the only true answer is that it isn't a paradox the universe/physics never defined a "ship" to be there. We did. And the only "paradox" is that someone found a flaw in our modeling algorithm. But again, there was never a single object there changing state.
So the long story is - don't judge a method of modeling on how effective it is. Because no model we use in everyday is actually the underlying "truth".
https://en.wikipedia.org/wiki/Ship_of_Theseus
> but the world does not truly exist of discreet objects changing state.
Really? So elementary particles don't change position, energy, velocity? Everything is static and immutable? And gets destroyed/recreated for everything that looks like a state-change to us? While I could imagine modeling the world that way, it is a description of the world that gets shredded to tiny little pieces by Occam's razor.
On a more basic level, just the fact that you can imagine a different interpretation doesn't mean that an interpretation I give is false. There is a difference between "false" and "there are other possible interpretations".
And the fact that you don't have a simple materialistic/reductive definition of what a "river" is, or any other macroscopic object, does not mean that rivers don't exist. If you can't see it, more power to those of us who can, like me, because we are going to have a much better time navigating the "real" world than you are, including taking bridges to cross those rivers rather than drowning, because after all it's just a few drops of water, right?
Or you are just pretending that rivers don't exist, and actually implicitly use this knowledge all the time to safely navigate the real world.
Which brings us back to immutability in programming: it's largely a pretense. It can be a useful pretense. I certainly love to take advantage of it where appropriate, for example wrote event-posters long before that became fashionable[1]. But in the same system I also used/came-up-with in-process REST [2], which is very much based on mutability.
So immutability is useful where applicable, but it is also very limited, as it fits neither most of the world above nor the hardware below, and trying to force this modeling onto either quickly becomes extremely expensive. Of course, many technical people love that sort of challenge, mapping two things onto each other that don't fit naturally at all [3]
This is actually false. A bit hand wavy here, but the world does not truly exist of discreet objects changing state. That's how we choose to model it, and it's useful, but it's not the "truth" of the world / universe.
A few simple examples - viewed at the quantum level, protons, neutrons, electrons aren't physical objects that "exist" in a unique place at a point in time. Now i'm not saying an imperative model is wrong because of quantum mechanics, but am merely illustrating that we chose to model the world as objects with changing states because it's useful, not because it's accurate or the truth.
The ship of Theseus is another examples. There really is no paradox here as there was never a "ship" to begin with. We just chose to model that particularly assembly of particles as an entity/object known as a ship, and gave it "state" that persists over time. But the only true answer is that it isn't a paradox the universe/physics never defined a "ship" to be there. We did. And the only "paradox" is that someone found a flaw in our modeling algorithm. But again, there was never a single object there changing state.
So the long story is - don't judge a method of modeling on how effective it is. Because no model we use in everyday is actually the underlying "truth". https://en.wikipedia.org/wiki/Ship_of_Theseus