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Information Is Physics

cacm.acm.org

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Re: Information Is Physics

#51

Post by knzhou »

ppod wrote: post #50

This reminds me a bit of David Deutsch's Constructor Theory. What's the mainstream acceptance of that like at the moment? https://en.wikipedia.org/wiki/Constructor_theory

I'm always ticked off when I hear the hype around constructor theory. While information theory has had profound impacts in physics, constructor theory has always seemed to me to accomplish nothing but add fancy words. Yet it has done very well trading on the past prestige of its proponents, and promoting itself through popular talks where no real scientists are present to question them.

For example, constructor theory "explains" why life exists. Their argument is as follows (condensing 20 pages of vague equation-free words into a few sentences): first assume that there exists a constructor for life. Such a constructor is defined to be an object that can create new life. This leads to the creation of more life. Therefore life exists.

I was so shocked by this that I reread their paper three times before concluding their argument really was that vacuous. Their physics-related stuff is similar: assume the desired conclusion, then pretend you've derived it by adding the vague term "constructor" everywhere. (To derive F = ma... assume F is a constructor for ma!) It's so content-free I literally can't find anything specific to criticize. But they keep getting press by making more and more outrageous claims.

The fact that tens of thousands of curious people around the world have been duped into thinking that it is on par with ideas that actually have content proves the absolute bankruptcy of science communication. It is also a warning to avoid blind trust in past credentials.

Re: Information Is Physics

#52

Post by cellular »

ci5er wrote: post #24
deepnotderp wrote: post #2

For anyone interested in this, the Landauer limit now has experimental evidence. Also, it is now believed that the Margolus-Levitin theorem puts a lower bound on energy even on reversible computations.

Weird. It's new to me that we didn't have experimental evidence before, but I guess it would have to be pretty subtle equipment. I wish I knew how to catalog/index my assumption/belief set, so I could scrub it down for unverified sub-assumptions from time-to-time. I'm happy to update them, when they are proven wrong, but I don't know how to do this methodically and as a result, my brain fills up with crap. And then I…

The foundations of our knowledge are very quickly based on assumptions/beliefs.

Light is not really understood. It's a wave and a photon, depending on what we need to solve. We incorrectly say light is a "wave", but "wave" is a verb!! I remember thinking this sounded ridiculous when I was in school. You probably did too! We should all go back and redo our assumptions like you say.

The other thing that disappointed me was the explanation of why magnets attract/repel. (Do you remember your feeling about it? Did your innocent child mind reject the explanation?)

Re: Information Is Physics

#54

Post by fixf »

csomar wrote: post #19

I think the next step for physics could be potentially in establishing the link between abstract information and what is perceived as "real matter".

Self squared dragons and monstrous moonshine.

Re: Information Is Physics

#56

Post by ngcc_hk »

Feed sad. It is really one of the few area has long term impact. Sadly my young fellow hkust student cannot have a chance to explore and see it. Even get a funeral house to refuse to burial him. Rip. Just not sure what to say.

Re: Information Is Physics

#57

Post by mantap »

cellular wrote: post #52
ci5er wrote: post #24

Earlier quoted context omitted.

Weird. It's new to me that we didn't have experimental evidence before, but I guess it would have to be pretty subtle equipment. I wish I knew how to catalog/index my assumption/belief set, so I could scrub it down for unverified sub-assumptions from time-to-time. I'm happy to update them, when they are proven wrong, but I don't know how to do this methodically and as a result, my brain fills up with crap. And then I…

The foundations of our knowledge are very quickly based on assumptions/beliefs. Light is not really understood. It's a wave and a photon, depending on what we need to solve. We incorrectly say light is a "wave", but "wave" is a verb!! I remember thinking this sounded ridiculous when I was in school. You probably did too! We should all go back and redo our assumptions like you say. The other thing that disappointed me…

Light is well understood but the explanation depends on what level of abstraction you require. There are quantum, classical and naive explanations of light and each are radically different. It's not our understanding that is flawed but rather the assumption that if there's two different explanations of the same physical phenomenon it indicates a lack of knowledge (rather than an abundance of knowledge).

Re: Information Is Physics

#58

Post by goatlover »

davidivadavid wrote: post #53

What else could it be? Everything is physics.

This is the same sort of claim as everything is water, the four elements, matter, mind, math, or according to this article, information. The difficulty as always is showing how everything is actually X. It started with Thales or Parmenides, and the allure of reducing everything to one substance remains with us to this day.

Re: Information Is Physics

#59

Post by davidivadavid »

goatlover wrote: post #58
davidivadavid wrote: post #53

What else could it be? Everything is physics.

This is the same sort of claim as everything is water, the four elements, matter, mind, math, or according to this article, information. The difficulty as always is showing how everything is actually X. It started with Thales or Parmenides, and the allure of reducing everything to one substance remains with us to this day.

Except physics is precisely not a substance. So let me ask that again, what else could information be? Even dualistic philosophies are conceptually reducible to "physics" because physics is all there is, by definition. To paraphrase George Carlin about the Earth and plastic, even if you think "minds" or "information" are not "physical" (by which people usually mean material, which is yet again something else), then redefine physics to be "old physics"+"that new arbitrary thing you named" and you'd still have physics.

Those discussions might involve interesting physics, but it's certainly clouded in very poorly chosen and confusion-inducing terminology.

Re: Information Is Physics

#60

Post by goatlover »

davidivadavid wrote: post #59
goatlover wrote: post #58

Earlier quoted context omitted.

This is the same sort of claim as everything is water, the four elements, matter, mind, math, or according to this article, information. The difficulty as always is showing how everything is actually X. It started with Thales or Parmenides, and the allure of reducing everything to one substance remains with us to this day.

Except physics is precisely not a substance. So let me ask that again, what else could information be? Even dualistic philosophies are conceptually reducible to "physics" because physics is all there is , by definition . To paraphrase George Carlin about the Earth and plastic, even if you think "minds" or "information" are not "physical" (by which people usually mean material, which is yet again something else), then…

Physicists certainly don't concern themselves with the study of everything. Take sociology or art, for example. At best you can you say everything is made up of physical stuff.

But even then, there are questions. Are math and logic made of physical stuff? What about causality or laws of nature? And what of universals or possible worlds or counterfactuals? If those exist, are they physical?

And then there's consciousness, and the ideas we have about the world, of which the study of physics is but one domain (containing concepts of energy, mass, fields, laws, information). Are these ideas physical?

What about the debate over the proper interpretation of quantum mechanics? Is that physical or philosophical? Is philosophy physics?

You quickly run into problems when you say that everything is domain X, because then you have to justify lumping everything into that category.

And the idea that everything is physics is open for debate, so clearly not everyone agrees that it is true by definition. Most things in philosophy don't get a free pass by virtue of definition, because people aren't going to usually agree to go along with said definition. Instead, they will want to ask what it means for everything to be physical.

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