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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

• Anon84 7y ago
  > 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...
  • pferde 7y ago
    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.
    • davedx 7y ago
      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.
      • pferde 7y ago
        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. :)
        • mathw 7y ago
          Well, what is information? Is it an abstract thing, or does it only exist in terms of the thing which is representing it? I don't have a clue, I just think it's a relevant question at this point.
      • blattimwind 7y ago
        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?
        • consp 7y ago
          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.
      • mpoloton 7y ago
        Electron rest mass is about 1E-31 Kg which is orders of magnitude more than the proposed estimated bit mass of 1E-38 Kg.
  • bognition 7y ago
    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.
    • ryandvm 7y ago
      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.
    • _carl_jung 7y ago
      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?
      • krastanov 7y ago
        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.
        • _carl_jung 7y ago
          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!
          • krastanov 7y ago
            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).
  • undecisive 7y ago
    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)
• radarsat1 7y ago
  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."
  • pferde 7y ago
    The last paragraph of TFA explains why it is left theoretical. In short, lack of measuring accuracy.
  • Deukhoofd 7y ago
    > 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. The article explains why it's not testable.
    • Brave-Steak 7y ago
      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?
      • Sean1708 7y ago
        From the paper: > For 1Tb device the estimated mass change is 2.5 × 10^-25 Kg. I don't actually know how precise we're currently able to measure mass, though.
        • trentlott 7y ago
          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
• ravenstine 7y ago
  It seems like a modern version of the early 20th century experiment to weigh the human soul. https://en.wikipedia.org/wiki/21_grams_experiment https://en.wikipedia.org/wiki/21_grams_experiment
  • mrfusion 7y ago
    Well if the brain holds a huge amount of information this could actually explain those experiments. weird to think about.
    • dTal 7y ago
      Even funnier, the information lost when a human dies really is their soul! The real question is, how many bits is a human soul? (To be clear - this is definitely not the explanation for those experimental results. But it's fun to kid around!!)
• jerf 7y ago
  "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.)
• m463 7y ago
  Sort of reminds me of the question, "does a battery weigh the same when charged as when discharged?" (on the other hand, I remember lead-acid car batteries are more prone to freezing when discharged)