Information Has Mass | Hacker News Reader

Information Has Mass

aip.scitation.org

54 points0011721 comments

This paper feels very unconvincing. It seems to just assume that there is some intrinsic entropy inside a particle which, by virtue of their annihilation, must be released. I'm fairly sure that is not at all what the Landauer limit is talking about. This cited paper https://aip.scitation.org/doi/10.1063/5.0064475 comes up a with a number and says it's intrinsic in each particle, but.. that just seems so sketchy.

The Landauer limit says: since entropy can't be destroyed, if an irreversible computation takes place -- if a bit is 'erased' -- the entropy must be released a heat. Then, using dE = T dS, that change in entropy ought to correspond to a change in energy.

Nowhere in this is it claimed that particles store intrinsic bits of information. It's just talking about data that is modeled in the _state_ of a system. Erasing a bit means collapsing two states of the system into one.

Also, maybe I'm being unfair here, but I'd guess that no paper about entropy that starts with "digital information storage technologies have radically transformed our modern society" is going to end up being good.

"Modelled" is exactly it. It's a mapping of meaning to changes in various states.

Not an expert and I know counterintuitive phenomena exist, but at bottom it makes way more sense that information is the effect of energy, not the cause of mass.

It's a property of energy transfer that incidentally requires you to take into account the existence of some entity to interpret/record/act on it. So how can such a thing as information have mass? Something must be backwards here.

What is information without its receiving entities, be they computers, signal relays, microphones or people? Or hard drives? Just changes in energy that sometimes change mass as well.

Any change in mass you care to measure is bound to change the information inherent in the object. That's the direction of the relationship: The change in mass/energy leads to the information, not the other way around.

For that matter, am I really making a sheet of paper heavier when I run it through a Braille printer? The example of the hard drive doesn't really provide clarity on this.

Yeah I suddenly had very similar questions and then read your comment.

If a bit exists but there's no one to encode it, does it inform?

Seems like a lot of what we think of as information is really "potential information" along the lines of potential energy.

Also surprising lack of quantum physics in the article.

I'd be interested in what someone in the field of quantum physics or computation would have to say about these issues.

I do research in information theory but in a totally different way.

> This paper feels very unconvincing.

Could you explain why you phrased it this way, as opposed to e.g. "I find this paper very unconvincing."?

This isn't a critique; I'm just trying to understand a recent drift in language, and if/how it corresponds to a difference in the underlying thinking.

In my upbringing, there's a strong delineation between "thinking" and "feeling". In that view, thinking is mostly about propositions, ideas, and logic; feeling is mostly about emotions.

My best guess is that "... feels ...", as used above, is meant to express a uncertainty about what follows.

I think in many contexts, “I think” means “this is complex, but I am prepared to articulate my position using logic,” and “This feels” means “my subconscious, experience, or instincts are telling me this is wrong, but I can’t yet articulate why in a logical, cohesive argument.” I will often use the latter to justify delaying decision-making or action while I formalize my argument.

Interesting question!

I don't actually like the way I phrased it. When I re-read the post I thought it was a bit awkward. It uses too many soft words -- both "feel" and "convince". I am trying to remember to not write that way, with so many heavily qualified and disclaimed opinions. The use of the word 'feel' is the wishy-washy hedge that I really don't like here, but yes, it is trying to disclaim and the certainty of the point, to sound less imperious. (It's also an awkward word because the phrase "the paper feels" is awkward English. Papers don't feel. It makes sense in context but still sticks out like a sore thumb.)

This habit has been infected the way I write everything over time and I don't think it's necessary. It's redundant: it's implied that everything someone writes is their 'take' on the matter. And it reflects trying to write exactly the words you would say if you were speaking, instead of using the slightly different language of written English, which doesn't need so many qualifications. I think the older I get the more I forget how written English works, like I'm losing touch with how to sentences that aren't just transcribed speech.

Although, there are some subtle differences in the connotations of a few ways of phrasing the point.

* " This paper feels very unconvincing" -> the paper has a quality of <very unconvincingness> in its text, which anyone could recognize.

* " I find this paper unconvincing" -> the unconvincingness is a quality of my body of knowledge.

* "I'm not unconvinced by this paper" -> the unconvincingness is a quality of how I reacted to it.

* "This paper is wrong" -> I have really good information that the paper is wrong, it's not just a layperson's hunch. I don't have a physics PhD and I've never felt like a person who is fully allowed to say things like this, even though I am pretty sure it's true.

* "This paper feels wrong to me" -> same thing but with one of those disclaimer words to undermine the claim.

I also find this absurd:

> The first proposed experiment to test the M/E/I equivalence principle involved the measurement of the mass change in 1 Tb data storage device before and after the digital information is completely erased. At room temperature, the calculated mass change for this experiment is in the order of ∼10−25 kg, making the measurement unachievable with our current technologies.

Erasing 1TB of storage isn't destroying information. It's changing it to store all zeroes or all 1's, or it may simply delete the file allocation table without deleting the data, depending on the erase function used.

What does tickle me though is that if someone is able to prove this, it proves that all mass and energy has information equivalency, which may pave the way to a proof of simulation hypothesis. In a simulation, we would all be information, and information would be perceived as mass or energy.

I find the idea that mass and energy are equivalent to information in some way plausible, personally. Just, this paper doesn't offer anything useful on the subject.

For the case of erasing a 1TB storage, I think it's fine to assume an abstract operation with no error correction or internal state. But even still, any wear-and-tear to the drive counts as data as well, and that's going to be incredibly hard to quantify. But if you got past all that, then the idea is that the quantum state of the <the drive + the erasing system>, if an isolated system, has to put that 1TB of entropy somewhere (since in principle the erasing operation must be reversible), and that it presumably becomes decoherent thermal noise. It's 10^-25 kg of energy _in the form of heat_, not anything useful like discrete photons.

The headline is misleading. This paper proposes an experiment to determine if the theory that information has mass is true.

I don't see a convincing reason why information conservation would need two additional photons. The author mentions himself in the conclusions that the standard two photons of the annihilation process could carry the additional energy.

On the contrary. Take a punch-card, stick it in your 029 keypunch, and add 80 bytes of information to it by typing away. Now it weighs less than when you started. Information has negative mass.

counter example.

consider that instead of punching out the holes, you added an ink blot, the ink is somehow reflective and thus is read by the machine (or whatever).

as the ink has a weight it now weighs more than when you started. Information has regular mass.

hence some prior assumption is mistaken and we could now prove something by contradiction.

now then, somebody please tell me if a proof by contradiction holds in constructive logic.

Showing that X implies a contradiction is showing not X in intuitionistic/constructive logic, yes. However, you can’t show X by assuming not X and reaching a contradiction. By doing so you would only show not(not(X))

Agreed; furthermore, your example is analogous to the classical way to answer a test by filling in the answer-sheet's circles with graphite pencils.

It has been said that a punched-card is the least-efficient form of data storage ever invented. The data is stored in the form of holes in the card. The card's only purpose therefore is to hold the holes in place, so it is 100% redundant.

Interesting perspective. Without the card around them though, the holes don’t exist.

But all the paper chips that you punched away are information too. So it's zero sum.

In a deterministic universe your typing doesn't add any information; any information was already there from the start.

The entire universe is holestuff and is already there by default. You add in the paper to tell the reader where the holes AREN'T.

Just a warning: professor A Dońda in the book “The Memoirs of a Space Traveler: Further Reminiscences of Ijon Tichy” (1973, by Stanislaw Lem) made already an experiment in such matter: while transforming information into mass he reached critical mass - what resulted in the disappearance of the contents of all computer data banks and collapse of human civilization.

Can someone explain to me, what actually constitutes that a particle has information or has no information? I.e., what would actually cause a change of this state?

I would expect, that having just 0 or 1 alone would not. Maybe it is related to an observer/environment, i.e. the reduction of the wave superposition to certain possible states...

Reply on news.ycombinator.com