The assumption seems to be that you can transfer mass and energy into information in a way that subtracts from total mass+energy of the system but still shows up when weighed.
To test the hypothesis it's not enough just to weigh the memory. You must ensure that the energy stored in the memory has not been increased, because energy increases the weight of the memory device. (relaxed spring weighs less than tensed spring, storing energy in capacitors increases the weight of the memory).
>Here we formulate a new principle of mass-energy-information equivalence proposing that a bit of information is not just physical, as already demonstrated, but it has a finite and quantifiable mass while it stores information.
(...)
>Assuming that all the missing dark matter is in fact information mass, the initial estimates (to be reported in a different article) indicate that ∼10^93 bits would be sufficient to explain all the missing dark matter in the visible Universe. Remarkably, this number is reasonably close to another estimate of the Universe information bit content of ∼10^87 given by Gough in 2008 via a different approach.12 In fact, one could argue that information is a distinct form of matter, or the 5th state, along the other four observable solid, liquid, gas, and plasma states of matter. It is expected that this work will stimulate further theoretical and experimental research, bringing the scientific community one-step closer to understanding the abstract nature of matter, energy and information in the Universe.
ps. AIP advances is so called scientific mega journal. It has very low selectivity and don't select articles based on importance. They are "peer reviewed" only in the lowest criteria possible.
Not in any of the usual meanings of "particle" (an "excitation of a quantum field", which of course is not a particularly elucidating explanation if you are lacking context).
In Light Emitting Diodes, electrons move across the electron transport layer, while "hole" particles move through the hole transport, where they meet at the heterojunction to combine and emit photon particles. Holes aren't really like other atomic particles, rather they represent the lack of an electron in an energy field that has an affinity for electrons. But it's still a type of manifestation of energy (or lack thereof), thus represents a unit of mass (albeit negative), which effectively signifies the presence of a manipulatable minute piece of negative matter - the definition of a particle.
So, I don't see why you couldn't use the particle label when referring to information. How about an "infon"?
Yes, holes exist and are a useful formalism. But you are wrong, holes very much behave like other elementary particles (pseudo-particles), and you get to call these things particles, exactly because they behave like excitations of a field.
If you insist, sure, you can make up an infon and call it a particle. However, it would not behave like anything a physicist would call a particle, nor would it use any of the mathematical tools that were developed to deal with particles, nor it would provide any useful intuition or insight, nor would it provide any pedagogical value. And at that point why bother calling it a particle if it does not behave like one.
From TFA: "“This idea is laboratory testable in principle,” said Vopson. He suggests taking mass measurements of a digital data storage device when it has full memory. If it has more mass than when the device’s memory is cleared, then that would show the mass-energy-information equivalence is correct."
While the idea is interesting, the actual proposed experiment is laughable. It's like suggesting that a mechanical light switch should have different weight when switched on or off.
> a mechanical light switch should have different weight when switched on or off.
Well, in principle it should have a different weight to account for the extra electrons moving around when it’s turned on. Every time you have a change in charge you have a corresponding mas change.
My problem with this idea is the fact that not all information is electronic in nature, in which case you would be arguing that the weight of a completed puzzle is different than the total weight of the individual pieces, for example.
In general, this would imply that changes in entropy would correspond to changes in mass...
It's more complicated than that. A single light switch stores exactly 1 bit of information. Its either on or off and both positions convey the exact same amount of information.
This raises what I view to be a falsification by counter-example of the original premise. If information (and not _the representation of_ information) has mass, then does a piece of uncompressed information weight the same amount as the compressed information?
Furthermore, information is related to interpretation. A string of bits may be an uncompressed text file, a set of numbers, a compressed image, etc. But it's always the same amount of bits. How can my interpretation of that set of bits affect its mass?
There are measures that do not depend on interpretation. Entropy of the content for instance. This is what people usually refer to in this context and the ideas of the article have actually been known to physicists for decades.
I'm out of my depth here as I've never studied information theory. I suppose there's a larger gap between the theory and the practical aspect of the title of this article than I first imagined!
Yeah, our everyday technology is maaaany orders of magnitude away from where this would be detectable. However, it is still important topic if we want to design extreme efficiency computing hardware (and already studied among researchers that want to make nanotech).
If the mass of information is strictly proportional to how many bits of entropy it contains, it follows that neither interpretation nor (lossless) compression can alter its mass.
There's quite a bit of difference between how we usually think about information and how information theory treats it. There it's all about entropy.
Doesn't the very definition of "lossless" depend on interpretation? If lossy compression alters its mass, but lossless doesn't, doesn't it depend on the interpretation of "lost" information?
As I said to the above poster I don't know much about this, so hope this isn't an off-base question.
The meaning of a certain sequence of bits depends on interpretation, of course. But nobody is talking about meaning here, only entropy. For our purpose it wouldn't matter if there were no sentient beings in the universe to attribute any meaning to anything.
Same as an SSD. Regardless of whether you saved anything on it the individual bits are either set or unset. It always has information on it, it just might not be _your_ information.
Yes, you summarized what I feel is wrong with the experiment perhaps even better than me. They are trying to weigh not the information itself, but medium used to convey the information.
It that true, though? Does an electronic storage device with full storage have more electrons in it? I don't know enough about how modern memory works to say for sure.
Electrons are used as the information storage mechanism in flash memory, but the data is whitened (50 % one bits on average independent of the data input) before being stored. Hence, "the number of electrons" would not vary between an SSD storing only zeroes, and one only storing ones.
But in any case, you would be measuring the mass of electrons and not the information they represent. This theory suggests that a storage device would have additional mass dependent on information content, so things like whitening / encryption would not matter.
However, here is a question that immediately occurs: If I have a message with "informational mass" x, and encrypt it, does the encrypted message has the same informational mass, or is the mass of the encrypted message the same as a random message of the same length?
Since flash is based on a charge pump, doesn't it just move the electrons from the substrate or control gate to the floating gate? Or am I missing something here?
In that case you do not have to account for the electron mass at all.
That's not really the point. The point is, they would be measuring the weight of the electrons, in other words, the implementation-specific medium used to store the information. Not the information itself.
I can see this discussion go very far into metaphysical. :)
Surely not though - we're talking about information.
You don't need electricity flowing for the light switch to store information. In fact, the light switch could have no spring in it, allowing it to be in an infinity of different states.
So let's imagine a board with two such light switches. I set one to 0.9998128376666.. and the other to 0.26757328888... - out of the infinite number of possibilities, how do we quantify the information that I've just stored in these light switches, to determine how much their weight should have changed?
It's a silly question. It's a bit like saying "If a tree falls in the forest, do birds contain sodium?" Of course the two halves of the question are related tangentially, but putting them together like this is totally meaningless. Oooh... and nests are a thing, so, is it trees falling in the forest that causes nests? (dark matter)
Weigh an SSD before and after storing data on it? That's so easy to do I have no idea why such an article would leave it as a theoretical.
edit: since I have been downvoted, perhaps someone would like to clarify how my description differs from, "taking mass measurements of a digital data storage device when it has full memory. If it has more mass than when the device’s memory is cleared, then that would show the mass-energy-information equivalence is correct."
> Unfortunately, taking the extremely small measurement needed to such precision may currently be unachievable. Vopson proposes the next step to getting answers could be developing a sensitive interferometer similar to LIGO or an ultra-sensitive Kibble balance.
Or you could just store a crazy amount of information on one medium that's big enough. Can somebody calculate how much it would need to be before it's measurable with modern instruments?
A proton weighs ~10^-27 kg, so that's about 100 protons.
I sincerely doubt we have masses that are quite that good - especially that which can take a high mass item (harddrive) and detect an atomic-scale change without being hideously noisy
it does not work that way because a SSD stores the information by capturing and binding electrons. Presence of an electron in the flip-flop (electric charge) is evaluated as 1 and non-existence of an electron is evaluated as zero.
A full SSD will be actually heavier :) but when you think about it the information amount is the same, a SSD with full zeroes and another one full with files have same amount of information equal to capacity of the SSD. Whether it is meaningful information or not is another discussion.
"He suggests taking mass measurements of a digital data storage device when it has full memory."
I hope this is just fuzzification from the usual science journalism process, but I worry there may be some equivocation (in the logical sense) there. What the universe considers "information" and what we consider "information" do not have to be the same thing. They will certainly be related, and as human!information approaches universe!information density, they'd converge, but up here in the macroscopic world there's a lot of daylight between the two.
Consider a simplified cell we use to store a bit, which can either have electrons piled up on one side for a 0, or equally piled up on an equal side for a 1. We humans might consider a drive full of random numbers to be full of information while a drive full of zeros is highly, highly compressible and thus nearly empty of information, but from the universe's point of view, we have exactly the same amount of excess "information" about which electrons are confined where no matter what we humanly store on this drive. That "information" would also constitute far more universe!bits than we could ever dream of storing human!bits on the same drive, while at the same time, not even remotely approaching the level we could hope to measure as mass.
Human!information is a lower bound on universe!information, and not a particularly good one, either.
It seems to me we have a decent grasp on what may constitute a "qubit" and how that may be information, but I've not seen a very solid discussion of what the universe may consider "information" in the arrangement of those qubits. I phrase it as "I've not seen" on purpose, since I'm not in the field. I do know I've seen very far-out speculation like the possibility gravity is somehow related to mass blocking the information flow in the universe in an asymmetric way resulting in a force, but IIRC that still had no discussion on what the information may be, beyond a mere aggregation of qubits. It's obviously there, but we don't know what it is. (Now there's a sentence that makes it sound like dark matter....)
(Thinking about this simplified cell I gave above, my crazy thought would be, if "information" in the universe and "a configuration of mass-energy that maintains its state even though there's a field trying to push it out of the state" (such as the electrons staying in their trap even though they are electrostatically trying to push each other apart) were the same, then there would be a clean mechanism for "information" to "have mass", in the additional potential energies involved. A disorganized mass-energy system where everything is already at the lowest energy would have no information. But this is just crazy talk.)
Let's say I have three 1TB drives - A, B, and C. A contains 1TB of meaningful data. B contains a sequence of randomly generated bits to be used as a one-time pad for encryption. I use B to encrypt the data on A, store this data onto C, and then destroy A.
B and C now can be combined to retrieve the information that was once stored on A. But B and C by themselves are just random sequences of bits. Where is the information, and therefore mass, of A, which still exists in B and C? If it is in one or both of B and C then I can destroy the information (and therefore reduce mass) in one by destroying the other.
One of the most interesting articles I ever read was in SciAm, arguing (from a thought experiment, Maxwell's Demon [1]) that information needs some minimum energy to be erased [2] (=reset to a low entropy state). Thus, there's definitely a connection between energy and information. Given the known connection between energy and mass, this would establish the final leg of the triangle.
I'm not certain that Maxwell's demon establishes enough of a connection between energy and information. I think you want more than just a connection, rather some kind of equivalence.
> He suggests taking mass measurements of a digital data storage device when it has full memory. If it has more mass than when the device’s memory is cleared, then that would show the mass-energy-information equivalence is correct.
Er... What?
What does it mean to "delete" information here? You put some movies on a usb drive, and then set everything to 0? and see if there's a mass difference? But a string of 0s is still information, no?
Yeah, as I mentioned in a sibling comment, erasure of data is an irreversible process that (because of thermodynamics) will always create heat (even of everything is a efficient as the laws of the universe permit). That heat is energy and it has mass. It is actually straightforward to prove it would have the same mass as the initial information pattern.
A string of zeroes and a random string do have different amount of entropy, so transforming between them requires energy.
I'm perplexed at what "AIP Advances" is supposed to be. This paper isn't an advance of any sort. It's an application of some decades-old formulas you can grab off Wikipedia; a high schooler could apply them to get this result. It adds nothing to "testability" (and is in fact wrong in its understanding of what "information" in a hard drive really is).
The journal has an impact factor of 1.5. For comparison, Science and Nature are in the 40s. This was a cute letter, but it should not have passed peer-review, whether it's open-access or not, because it contributes nothing novel.
Weirdly it's not like the author is some crackpot nobody, he has actual papers under his belt[1] and is a Senior Lecturer[2] (although not at a particularly prestigious university, admittedly).
His other papers are all in solid-state physics. He's a real scientist playing around outside his domain, discovering a well-known result, and writing a fun letter about it to a low-impact journal.
All of which is fine. It just requires a bit more context than the headline yields. If this had linked to his blog, it would make a lot more sense.
No, because the erasure of the information (irreversible process) will create heat (this is one of the postulates of thermodynamics). Heat is energy which also has mass. It is fascinating how nature provides for these amazing "near coincidences" and then finds a way to close the loophole.
I just had to check my computer's calendar - nope, not April 1st yet.
This is absolutely idiotically bonkers.
Information can be stored with mass, but is not the same as mass. They are not equal. I can't believe anybody is even trying to think up ways to disprove something so momentously bonkers. I mean sure, that's what science does... but buhhhhh
Read the paper. Unfortunately this “radical idea” operates completely within known thermodynamics and is just calling energy associated with thermodynamic non-equilibrium “mass of information”. Energy is information in that sense, so this adds nothing.
This article fails at being precise about what 'nformation' is. Some physical pattern only represents a '0' or '1' if we mean it to.
> Experiments have proven the process of deleting a bit of information dissipates heat energy, but after information is created, it can be stored with no energy loss.
To be precise here 'deleting' is a reduction in the number of possible states of a closed system. All '0's or all '1's is not a state of low information. They are both highly ordered states. The state of no information is total randomness, as in heat death. It does require energy to maintain (i.e. keep storing) for information (an ordered state).
Are they implying that a storage drive with bits organized to store specific data(say an mp4 file, or the meaning of life) will way more than a drive with randomly arranged bits? If not then aren't they just measuring whatever mechanism is used to physically represent the bits, and not the information itself?
And if so that does seem quite unbelievable. Wouldn't that mean that if you had 2 tiny harddrives that both stored the number 3.14, one harddrive happened to store that number after randomly assigning the bits and one harddrive purposely had 3 digits of PI saved on, the one that was purposely storing the number would weigh more?
For what I understand, the proposal- with its suggestion that it may account for dark matter- seems to imply that two different arrangements of exactly the same particles can have different mass, depending on how much information those arrangements encode. Because otherwise, if "information" is intrinsic to each particle and not a collective property, then I don't see how its mass wouldn't be already accounted for by the particles' mass.
What kind of storage device? I'm fairly sure in a HDD the 1 and 0 states have the same energy, and from what I know about SSDs I think the same is true there.
I don't have a great understanding of SSD's but I believe the data is stored as charge in floating gates. And this charge should have weight.
For HDD's I think I was wrong but there is on the other hand an interaction effect between nearby bits. If nearby magnetic domains try to repel each other it has higher energy.
So basically we have rest mass and relativistic mass. How those two compare? And when we say: energy - mass equivalence we actually mean energy - relativistic mass equivalence?
No. You gotta be extra careful when you introduce relativistic mass.
Photon has momentum, zero rest mass. Energy mass equivalence says that you can annihilate mass to create a massless particle. This is true for all the observers.
Relativistic mass is a perceived mass dependent on the observer.
To test the hypothesis it's not enough just to weigh the memory. You must ensure that the energy stored in the memory has not been increased, because energy increases the weight of the memory device. (relaxed spring weighs less than tensed spring, storing energy in capacitors increases the weight of the memory).
The paper: https://aip.scitation.org/doi/10.1063/1.5123794
>Here we formulate a new principle of mass-energy-information equivalence proposing that a bit of information is not just physical, as already demonstrated, but it has a finite and quantifiable mass while it stores information.
(...)
>Assuming that all the missing dark matter is in fact information mass, the initial estimates (to be reported in a different article) indicate that ∼10^93 bits would be sufficient to explain all the missing dark matter in the visible Universe. Remarkably, this number is reasonably close to another estimate of the Universe information bit content of ∼10^87 given by Gough in 2008 via a different approach.12 In fact, one could argue that information is a distinct form of matter, or the 5th state, along the other four observable solid, liquid, gas, and plasma states of matter. It is expected that this work will stimulate further theoretical and experimental research, bringing the scientific community one-step closer to understanding the abstract nature of matter, energy and information in the Universe.
ps. AIP advances is so called scientific mega journal. It has very low selectivity and don't select articles based on importance. They are "peer reviewed" only in the lowest criteria possible.