In Episode 66 there was a long discussion about an idea I ve

Question

In Episode 66 there was a long discussion about an idea I ve come to know as the reality of abstractions I got that phrasing from David Deutsch in The Beginning Of Infinity I ve long wanted to write about this in connection to programming where we talk a lot about abstractions but in a very different sense to the way Deutsch does In lieu of doing that which sounds like a lot of work I will just post some of my favourite Deutsch quotes about it gt Reductionism and holism are both mistakes In reality explanations do not form a hierarchy with the lowest level being the most fundamental Rather explanations at any level of emergence can be fundamental Abstract entities are real and can play a role in causing physical phenomena Causation is itself such an abstraction gt When we use theories about emergent physical quantities to explain the behaviour of water in a kettle we are using an abstraction an idealized model of the kettle that ignores most of its details as an approximation to a real physical system But when we use a computer to investigate prime numbers we are doing the reverse we are using the physical computer as an approximation to an abstract one which perfectly models prime numbers Unlike any real computer the latter never goes wrong requires no maintenance and has unlimited memory and unlimited time to run its program gt Abstractions are essential to a fuller explanation You know that if your computer beats you at chess it is really the program that has beaten you not the silicon atoms or the computer as such Nor I would add the arrangements of pixels on the screen which symbolize knights pawns etc The abstract program is instantiated physically as a high level behaviour of vast numbers of atoms but the explanation of why it has beaten you cannot be expressed without also referring to the program in its own right That program has also been instantiated unchanged in a long chain of different physical substrates including neurons in the brains of the programmers and radio waves when you downloaded the program via wireless networking and finally as states of long and short term memory banks in your computer The specifics of that chain of instantiations may be relevant to explaining how the program reached you but it is irrelevant to why it beat you there the content of the knowledge in it and in you is the whole story That story is an explanation that refers ineluctably to abstractions and therefore those abstractions exist and really do affect physical objects in the way required by the explanation To connect this to the content of the episode I think all the different representations of a cube on a screen are real The parts that you might dismiss as not having an effect on the world like the data structures in RAM or the textual representation stored on disk are as unavoidably real at their own levels of abstraction Colloquially I think working programmers use abstraction to mean things ranging from I can ignore the details below this point to I can this implementation into fewer syntax tokens A from Dijkstra which I think is closer to Deutsch s view is abstraction as a new semantic layer in which one can be absolutely precise

Ivan Reese · Answer

For one this is lovely Thank you explanations do not form a hierarchy but they may feel like they do and I think that feeling is more real than this whole non hierarchics idea and probably more real than whatever the feeling pertains to Yes this is my attempt at philosophical humour Sigh sorry carry on

Daniel Buckmaster · Answer

To pirouette your humour into a serious point I think that there are hierarchies but usually many overlapping hierarchies The hierarchy with feelings at the top or bottom organises the world into one tree of explanations A hierarchy with a different root produces a different tree

Kartik Agaram · Answer

See also Christopher Alexander s A City is not a Tree whose punchline is that we should all deal with the complexity of lattices a lot more when we deal with the idealized spherical cows of hierarchies without overlapping parts

Daniel Buckmaster · Answer

gt For the human mind the tree is the easiest vehicle for complex thoughts But the city is not cannot and must not be a tree The city is a receptacle for life If the receptacle severs the overlap of the strands of life within it because it is a tree it will be like a bowl full of razor blades on edge ready to cut up whatever is entrusted to it In such a receptacle life will be cut to pieces If we make cities which are trees they will cut our life within to pieces

Andrew F · Answer

Going just by the quotes not having read Deutsch s book he seems to lean really hard on the concept of explanations being important and basically assumes that if something is useful or even essential for an explanation that makes it real I think this is extremely wrong Explanations are just another model and all models are wrong Even if you can t write in terms of fundamental particles how the x86 PC running Stockfish beat you at chess that has no actual bearing on the ontology of abstractions That s a statement about your own information processing ability not about reality One can imagine a superintelligence that can in some sense directly understand highly complex systems enough to predict its outputs as well or better than the abstract view without the need for intermediate abstractions though it would certainly understand those too More accessibly imagine a system where humans can both directly understand it and describe it in abstract terms and imagine how we would see an entity who can only handle the abstract description and concludes that it is equally real to the deeper one even if in fact the abstraction is leaky the example stuck in my head is temperature vs individual particle velocities but it s not great because it takes really weird circumstances to break temperature as an abstraction

Konrad Hinsen · Answer

A frequent confusion is to take strata as a sign of hierarchy Many systems are layered including systems of abstractions but this doesn t imply that higher layers are or should be in control of lower layers Interactions go both ways

Daniel Buckmaster · Answer

gt Explanations are just another model and all models are wrong I think Deutsch would probably agree with this The beginning of infinity in his book s title is referring to his fallibilist philosophy that our explanations and models will never fully capture the entirety of reality that we will improve on them infinitely that there is no upper bound on the creation of new knowledge By real in the quotes above I think one should read something like our best current approximation of reality not absolute objective reality itself gt That s a statement about your own information processing ability not about reality I think Deutsch s argument there is that even assuming you can model the entire operation of the computer down to whatever most granular level we are currently aware of even then it would be an incomplete explanation because it would not capture the higher level abstractions that are real Chess is as real an abstraction as algebra Temperature not so much I think it s a rule of thumb that works well locally like Newton s laws But the rules of chess work universally

Alex Cruise · Answer

I ve had a bullshit microtheory rattling around in my head for a few years It s easy to say that some Playmobil things are smooth surfaced modules that expose a limited number of abstractions and other Lego things are more like assemblies whose compositional properties are not accidental but useful But when you move up and down the layers of nesting you find that these properties almost alternate e g most people would agree with characterizing a smartphone as much more of a Playmobil thing than a Lego thing but if you open it up guess what it s composed of a bunch of specialized bits Each of which is trying really hard to be a module not a Lego thing

Alex Cruise · Answer

Drill down another layer into say an IMU module it s an assemblage of a bunch of truly wild MEMS hacks that are not only invisible from the outside but will break if exposed to atmosphere

Alex Cruise · Answer

gt a new semantic layer in which one can be absolutely precise +1 and also <https en wikipedia org wiki All models are wrong|all models are wrong some are useful> wink

Alex Cruise · Answer

gt Now it would be very remarkable if any system existing in the real world could be exactly represented by any simple model However cunningly chosen parsimonious models often do provide remarkably useful approximations For example the law <https en wikipedia org wiki Ideal gas law|PV = nRT> relating pressure P volume V and temperature T of an ideal gas via a constant R is not exactly true for any real gas but it frequently provides a useful approximation and furthermore its structure is informative since it springs from a physical view of the behavior of gas molecules For such a model there is no need to ask the question Is the model true If truth is to be the whole truth the answer must be No The only question of interest is Is the model illuminating and useful

Alex Cruise · Answer

gt lt https www youtube com watch v=9X4frIQo7x0 gt |truly wild MEMS hacks gt

Alex Cruise · Answer

The reason everything is built out of bits not atoms is that in the digital realm abstractions actually work mostly sometimes please

Andrew F · Answer

gt By real in the quotes above I think one should read something like our best current approximation of reality not absolute objective reality itself gt I can only interpret this as by real in the quotes above one should read definitely not real Once you ve admitted we don t understand reality we only have our current best approximation you ve already reached the correct conclusion Moving on from there to redefine real to something more conveniently accessible is not justified IMO you continue to need separate terms for real and current best understanding and hey both those existing terms do alright You can t lose track of what you re optimizing your models toward what you re measuring them against

Andrew F · Answer

I think I m prepared to endorse the idea that math and programming enable one to create abstractions that are equally real in whatever possibly multidimensional way you want to grade reality realness to whatever they are defined in terms of

Daniel Buckmaster · Answer

< Andrew F> I think that I ve misled both you and myself by including the kettle example and then reading real the way I did to make it fit with the rest of what s going on After thinking through it again I should emphasize that most of the things Deutsch is calling real through that chapter are more like chess war Manhattan prime numbers not models or rules of thumb about the physical world I think models and abstractions share similarities but I d hesitate to call a model real in the way I would call mathematics real and I think your objection is to doing that For example it s not right to say that mathematics is real because it is our current best approximation of what Nor is it right to call Manhattan real because it is a current best approximation And when programming we often deal with both abstractions and models The cube in the pod episode was an abstraction Customer is an abstraction when writing a CRM as are IMO many business rules Their applicability or reach is more limited than mathematics but within their own tiny worlds I d argue they re real

Andrew F · Answer

Wasn t I the one to bring up thermodynamics Just looking for a simpler example than war D I m still not willing to give Manhattan the same status as fundamental fields or whatever those end up being made of Even to the extent the physical boundaries are sharply defined they only have effect in a very fuzzy way mediated by human brains Useful model only approximately real Math is a tricky case We really want to believe that it exists outside our heads I too feel the platonist urge But the fact is the rules can be redefined whenever we want Even logic only exists as a field of study because the rules are mutable first order higher order linear etc It s hard to even call math an approximation in the same way Manhattan is Math itself can t be measured against anything to verify it I m not sure at this point what you re calling a model vs an abstraction but I don t think mathematics can be the same one as Manhattan chess war I guess in my mind when you start seriously asking about what s real I draw the line at fundamental fields or whatever those end up being made of If you re talking about math or software I think you re asking an analogous but fundamentally different question in an imaginary world where base reality is defined by the language implementation or something so the answer is different too You can do useful work there but if you try to zoom out it collapses back into physics

Daniel Buckmaster · Answer

The kettle was briefly in my original post I thought your reference to temperatures versus particle velocities was a continuation of that I think we re past the point that I can argue from my own position all the things I want to reply with are more Deutsch quotes and that is tiresome so I ll refrain I highly recommend his book it sounds like you ll have plenty to disagree with

Stefan · Answer

What is real is very much dependent on how you make sense of the world Scientifically realness seems to be related to truth If you can make true statements about something it feels more real than when the statements about it turn out to be false Eventually in pretty much any scientific discipline including math or theoretical physics you ll bump into issues with modeling the real world some of which you touched on above It seems our hope of a completely objective external reality of which we just have to figure out its rules is not achievable either because formal systems cannot be powerful enough incompleteness or because models begin to face issues with observation itself observer effect Yes incomplete models that assume independence from observers have turned out to be immensely useful and brought us scientific and then industrial revolutions But they are ultimately still limited So you could either try to figure this out and reconcile this and at least one Nobel prize will be yours or you d have to open yourself up to the idea that realness is perhaps just a subjective experience you have which in the knowledge category of belief in true propositions comes across as quite independent and universal so you might feel the urge to object to its subjectivity for as long as you can Maybe that sounds unscientific but many different fields including hardcore theoretical physics and quantum mechanics conclude that models of the world can t just be independent of the observer but need to include the observer within the model and boom now you have to deal with consciousness and the mind body problem The word real seems so simple and clear and insignificant that all this metaphysical and philosophical depth seems unnecessary to unpack just to talk about things like models or abstraction but look at how consistently we end up in debating definitions There aren t really statements about reality and then statements about your own processing ability Every statement we make will necessarily be about both simultaneously

wtaysom · Answer

Hmm the measurement problem It s a big jump from quantum observer to conscious one but it s a jump that plenty of physicists have been willing to make and then unmake later <https www youtube com watch v=CT7SiRiqK Q>

Stefan · Answer

Just judging from the video make and then unmake later doesn t mean they realized they were wrong and corrected their mistake but that it s a lot more complicated I admit that I jumped over a lot of complexity there and I wasn t even aware that there actually was an assumption of such a direct connection between quantum to conscious observer and I m not surprised that this didn t hold for long I only knew about some other more complex hehe entanglement between the two Bohm Hoffmann Penrose Wolfram come to mind as names of people who had things to say about that some of them quite recently It seems the connection between the deepest foundations of physics and the mind are a very hot topic still and that is true for both sides where psychologists and cognitive scientists and even AI researchers are running into issues with physics when they nerd hard about what consciousness could be Well you studied quantum mechanics and for sure know more about that than I ever will I d be interested to learn more so please keep sending pointers I wasn t trying to explain the metaphysics however I m not clever enough to do that I m mostly just trying to point out that the Cartesian idea of a mechanistic reality following universal rules aka truth that just needs to be discovered and understood is often still the prevalent folk theory that undergirds our discussions for interesting reasons especially in tech but is itself limited profoundly challenged in many disciplines and introduces all kinds of issues that we can only deal with properly by stepping out of this system And there are other theories that allow us to do that and I m not talking about mystical or esoteric ones but equally scientific ones that offer at least some interesting ideas that we software people could benefit tremendously from learning about so we can stop running into the same issues over and over again

Beni Cherniavsky-Paskin · Answer

Hofstadter in Gödel Esches Bach had pretty similar arguments in a whole chapter on reductionism vs holism The leading example was Aunt Hillary a sentient entity that is physically an ant hill ant where the ants and chemical signalling happen to implement rules isomorphic to some symbol activation He argues that while the ants are real they hold little explanatory power for her thinking the relashionships between symbols are more insightful and those explanations won t care much if you replaced the ants with neurons or a software model

Beni Cherniavsky-Paskin · Answer

I loved that because 1 it gave useful meaning to mind body dualism without dragging in religious mystic axioms 2 this philosophic idea is particularly clear amp quantifiable to us programmers through the measure of portability What would it actually take to swap one underlying platform for another

wtaysom · Answer

Aunt Hillary wasn t a Chinese ant hill by any chance

Daniel Buckmaster · Answer

Deutsch cites Hofstadter in the chapter I m quoting from extensively on the domino machine which sounds like a very similar concept

Beni Cherniavsky-Paskin · Answer

One interesting angle is porting vs emulation If I recompile my Go program for another CPU OS and it works with little modification that proves the underlying instruction set or OS didn t matter much the Go level concepts functions interfaces channels etc and OS concepts files etc have a reality of their own On the other hand if I have a C game directly accessing IBM PC registers and playing with interrupt vectors I can still run without modifications on another CPU OS inside an emulator like DOSBox but that s different The hardware and DOS BIOS internals now do matter and they still exist byte for byte in DOSBox even if virtually The C level behavior hern cannot be understood other than by reductionism to assembly level concepts At least not all of it Some parts probably have abstract reality Ironically if you look one layer above to the player s experience that s usually well insulated from the implementation If you ask a player what game XYZ is they ll probably talk of the game rules strategies for winning plot etc and not a particular sequence of bytes on disk implementing those And they certainly won t care whether the implementation used abstract layers or strongly tangled with lower layers Well unless you get into glitching cheating modding which are things many gamers enjoy too