Live data from Hacker News

What is emergence?

axispraxis.wordpress.com

11–20 of 73 posts

Re: What is emergence?

#11

Sometimes I think there is other information that gives the physics its meaning. For example, if you took a Shingled Magnetic Recording hard drive filled with VP9 encoded movie files on a NTFS partition, even if you perfectly understood the physics, and figured out all the individual magnetic fields, you would still have a rough time making sense of the of what was on it without this higher level information informat…

That's a good one. I also wonder how many other maps there are, and what _they're_ good at. Consider physics really deep and full of leverage that's currently really helpful to humanity...but still only one general system of map design. The nice thing is that lots of alternatives are considered within physics, but we also like our "best" concept; take Wolfram finding the "best" universal rule system for example. This immediately begins discarding alternatives. And maybe they're just different, not just worse.

Even the map metaphor starts to break at this point because it's hard to think of an alternative map that's not a literal map, and maps all seem the same (i.e. resolving down to the geometry-based, literal "map system" we already know) if you squint your eyes enough. The map is the territory, and it's not, and we can say the same of the pencil, and your shoes, and the concept of intuition. Just as a way of putting "known physics is the map" into context.

Re: What is emergence?

#12
This essay feels like "philosophy lite[0]." One one hand, it's great to introduce new eyes and ears to these deep concepts, but on the other, there's a deep historico-philosophical morass that one needs to wade through to get to the modern state of the art. There's an incredibly rich corpus discussing emergent properties[1] (most notably of which is, arguably, consciousness) but even the SEP article (which is orders of magnitude more informative than the blog post) is quite terse.

[0] For example, putting emergentism and reductionism on two ends of a spectrum is not strictly correct. There are reductionist emergent theories out there (in both phil. of science, as well as phil. of mind).

[1] https://plato.stanford.edu/entries/properties-emergent/

Re: What is emergence?

#13

Obligatory thesis that cracks this open: "Emergence: The Connected Lives of Ants, Brains, Cities, and Software" An utterly phenomenal book: https://www.amazon.com/Emergence-Connected-Brains-Cities-Sof...

Thanks for the recommendation, just got it on Amazon! I generally buy every (interesting) book I see mentioned on HN, and here's hoping it's a good one ;)

Re: What is emergence?

#14

Sometimes I think there is other information that gives the physics its meaning. For example, if you took a Shingled Magnetic Recording hard drive filled with VP9 encoded movie files on a NTFS partition, even if you perfectly understood the physics, and figured out all the individual magnetic fields, you would still have a rough time making sense of the of what was on it without this higher level information informat…

There are certainly levels that we can't comprehend because we are physically incapable of it, just as an ant is incapable of understanding a book. Perhaps with neural augmentation we will discover new vistas previously unavailable to us.

Re: What is emergence?

#15

The issue is that emergence is just some arbitrarily picked meaning of something observed from a certain "distance" or from a certain perspective. Emergence is not an intrinsic property of anything, it is just a (subjective) point of view. It is just another way of saying that things look different from different "zoom levels", hence we assign different models and/or meanings to them at each different level. But that…

Why is that an issue?

You choose, somewhat arbitrarily, a particular level of reductionism to apply. (It seems from what you are saying that you would agree that) atoms are real, but bricks are not; bricks are what we call a clump of iron, oxygen, silicon, aluminum, etc. which is mostly stuck together in a particular shape and size. Bricks are based on a human perception of togetherness and objecthood that is completely arbitrary; there's no real delineation of the edge of a brick, nor is there a real definition of 'brick' in the first place.

All of this is (more-or-less) true. Yet, at the same time, not only can I move the slide to a place where the brick is very real (say, when it's smashing out your brains after being wrapped in a slice of lemon), I can also move it to a place where atoms are no less emergent than bricks. 'Atom' is just the name we give to a cluster of quarks in various configurations, with an electron (kind of, arguably) nearby.

Yet, atoms are a construct present in physics because they're useful in making predictions about physical phenomena. Nothing fundamental about it. And bricks are a construct in engineering and architecture because they have a certain functional and aesthetic purpose in each of those disciplines.

It's all always arbitrary. It's all always human understanding. Science is human understanding. The question is not 'is this just an artifact of human perception', the question is 'is this relevant to the questions I am asking'.

Re: What is emergence?

#16
post #12

This essay feels like "philosophy lite[0]." One one hand, it's great to introduce new eyes and ears to these deep concepts, but on the other, there's a deep historico-philosophical morass that one needs to wade through to get to the modern state of the art. There's an incredibly rich corpus discussing emergent properties[1] (most notably of which is, arguably, consciousness) but even the SEP article (which is orders…

I think the description feels klunky and kludgy because it leaves out a key aspect of what physics sees in emergent properties[1]; these are properties arising out of the interaction of an ensemble of elements. And looking at your link, it seems most "emergentists" also were specifically considering ensembles. But article just says: "Emergence occurs when there is a conceptual discontinuity between two descriptions targeting the same phenomenon.", which seems too broad and so unilluminating.

[1] https://en.wikipedia.org/wiki/Emergence

Re: What is emergence?

#17
If you imagine the physical world as a vast machine. Something like a cellular automata, you can imagine theories about the universe as ‘compressions’. Parts of the universe which show repeating patterns can be explained by theories, which can be used to make predictions about future state. Sometimes the universe permits such theories and some times it does not. Sometimes it’s irreducibly complex and there is no ‘compression’, no pattern.

Re: What is emergence?

#18
When I was a kid, I was fascinated by the word "emergence". In pop science, it was spoken in reverent tones. Never mind that they never gave a definition of it that didn't sound trivial -- the word was dripping with meaning and the promise of hidden wisdom.

I went to college and studied physics. I learned how the behavior of many atoms leads to thermodynamics and the properties of materials. I learned how elementary quantum mechanics leads to atomic physics and chemistry. I learned how the strong force gives rise to nuclei. I learned how the Standard Model produces everything on this list. I learned how, at each layer, the correspondence was fiendishly subtle, but the work of thousands of physicists over decades had built the bridges.

At the end of it, I was still dissatisfied, because I hadn't learned what emergence was. I'd see crackpots presenting their personal theories of everything, declaring that they knew what no physicist ever could, because their model had emergence. They knew about it, and we didn't. But I still didn't know what it was.

Then I dug deeper and it became obvious. Emergence is a beautiful idea that has always been present, in some form or another, in every field of science. It is so well-developed in some fields, such as particle physics, that it has become a suite of quantitative methods with incredible accuracy. I had been learning it the entire time, and now use it every day without a second thought. Meanwhile, "emergence" is a brand name. It's a specific word passed down over generations of pop science used to convey mystique. It's a tool some charlatans use to pretend they know more than they do.

No offense meant to the article, but I often hear people say they're most excited about some substanceless theory because it "has emergence", and this is part of why.

Re: What is emergence?

#19
Entities have state (including position) and ways of interacting with each other. This leads to new state in the next moment, which leads to new state in the moment after, and so on. Thus the more global state affects the future state. There’s nothing mysterious about any of this.

Usually when people make a deal about emergence they’re confusing the map for the territory. They couldn’t predict the overall state evolution just by considering the parts.

They’re thinking of their notion of the generic entity type. But all that’s out there in the territory are the entity instances with their specific state.

The parts can’t exist in a stateless fashion. It’s just that in our heads — the map — we can consider them in that fashion.

Re: What is emergence?

#20
This reminded me of the hard science fiction novel Dragon's Egg by Robert L. Forward.[1] Its core idea is that complex, intelligent life could be possible on the surface of a neutron star.

He went to a lot of effort to try to come up with a plausible description of what "life" would be like in such an environment. That fired my imagination also, and I wondered how we could do such a thing in a scientific manner. Given the rules of the Standard Model, in principle almost all aspects of the surface conditions could be elucidated, but I feel we would be missing almost all of the essence of it. Just like a deep understanding of Quantum Electrodynamics won't help you determine from first-principles that Earth has pretty sunsets or that your hair stands up if you take a wool jumper off.

For example, the surface of a neutron star would be very bright in gamma rays, but those are subject to pair-production in the strong magnetic field of the star, making light effectively a short range sensory mechanism. Meanwhile, the enormous density of the crust means that it transmits sound incredibly well and at enormous speeds[2], making acoustics the equivalent of our photon-based vision sense! But it would hemispherical at short range and 2D in a complicated way at long range. Spacetime itself would be strongly polarized, atoms would be distorted into spindles and have strongly anisotropic behaviour, general relativistic effects could be felt in everyday scenarios, and there are likely dozens of other effects the we can't even fathom by merely staring at a handful of field equations that we developed in our comparatively cold, flat spacetime.

1] https://en.wikipedia.org/wiki/Dragon%27s_Egg

2] The speed of sound in Neutron stars is just under 0.578 times the speed of light! https://physics.stackexchange.com/questions/54684/is-the-spe...

Post reply on HN