5 ms·

Former mathematical physicist here. I haven't read the article yet so don't take this comment as a defense nor as a rebuttal, but I just want to point out that

by jmf1sh 5y ago

Former mathematical physicist here. I haven't read the article yet so don't take this comment as a defense nor as a rebuttal, but I just want to point out that your reasons for immediate dismissal are not obviously valid. - The Bekenstein-Hawking black hole entropy directly relates information to entropy. There has been an "it from bit" program (and more recently "it from qubit") dating back decades that tries to treat information as somehow fundamental with matter/energy emergent. The jury is still out, but I wouldn't consider it to be particularly controversial (at least not moreso than other speculative theoretical physics). - To me it seems absolutely physically plausible that cooling a hard drive to absolute zero would destroy its contents. As another example, you can destroy the information contained in DNA at much warmer temperatures than absolute zero. Why would heating it back up restore the information? Most thermodynamic processes are irreversible. And by the way, thermodynamic irreversibility is related to entropy change, which is a measure of information lost.

JohnHaugeland 5y ago
> To me it seems absolutely physically plausible that cooling a hard drive to absolute zero would destroy its contents. Cool, cool. It doesn't, but enjoy. Why would you imagine this would happen? The magnetic domain is not affected thus, and neither are MOSFETs. You're a mathematical physicist? You're the single least likely person on Earth in my imagine to say "oh, you reduced the speed of some atoms? That must mean magic happens." What could possibly wipe a hard drive from the action of cooling it down? . > Why would heating it back up restore the information? In short form "it doesn't." You may be confusing that some heating processes create damage with the idea that warming something up will harm it. As any schoolchild can tell you, DNA has survived billions of years on this planet, being heated and cooled somewhat rapidly throughout.   > And by the way, thermodynamic irreversibility is related to entropy change, which is a measure of information lost. This is a very "consider a spherical cow" approach to physics. The reason physicists are made fun of on those grounds is that the abstractions they bring to the discussion are frequently so far divorced from the real world situation that by the time you start bringing the real world back to the discussion, their abstractions fall apart. Real world objects that were not designed for durability have not suffered this damage on the timescale of a fifth of the length of the universe. That things are irreversible and related to one another isn't much use when you look at the real world and the things you're describing aren't actually happening at large scale, even in uncontrolled natural conditions. An insect that's been in amber for 500 million years typically has DNA loss on the order of ~5%. It has been exposed to a wild range of temperatures. If you genuinely believe that exposing a hard drive to absolute zero would destroy it, help us understand why Voyager is still running. Maybe it's because it's still a tenth of a degree kelvin above absolute, or something?
- rcxdude 5y ago
  There's a huge difference between exactly zero and close to it. Space isn't even that close compared to what's been done in a lab, and even in lab experiments the temperatures involved don't correspond to such effects happening.
  - JohnHaugeland 5y ago
    Cool story. Did you have an actual explained mechanism by which this is going to happen? Because if you're saying "exactly zero and close to it," we've never actually had a single atom at exactly zero, let alone a macroscopic object
    - aeternum 5y ago
      We can get close enough to absolute zero that very weird quantum effects being to happen which one could argue are associated with information loss. Cooper pairs is one such example, where at very low temperatures electrons pair up and begin to behave like a new combined particle with integer spin. Thus they morph from fermions to bosons which are no longer subject to pauli exclusion and can all occupy the same state. The information required to describe such a system decreases substantially as the potential state space is now quite limited. This manifests in physical phenomenon like superconductivity and superfluidity.
      - JohnHaugeland 5y ago
        We cannot do these things macroscopically, no. I will repeat my protest which you ignored from the previous comment. 1) We have never reduced even a single atom to absolute zero. Practicioners debate whether it's actually possible. 2) Your discussion of bose-einstein condensates is neat and all, but the explicit context is a hard drive. Nobody has ever condensed a macroscopic object (the breathless article about condensing a tardigrade isn't actually correct.) There has never been a superfluid or superconductive hard drive. Please focus on the question being asked, in the context being asked, if you must reply. How do you propose to reduce a hard drive to actual non-almost zero degrees? Not a few particles, not electron pairs. A hard drive. Once it's at absolute zero, formally, so what? Yes, I saw you guys handwaving "spooky stuff happens," but in reality, we've had hard drives within a tenth of a degree kelvin and nothing happened. If you're going to propose effects, please have a specific mechanism in hand that creates the specific effects asked about, in a context that is the hard drive and not two electrons Thanks

by jmf1sh 5y ago

JohnHaugeland 5y ago

> To me it seems absolutely physically plausible that cooling a hard drive to absolute zero would destroy its contents. Cool, cool. It doesn't, but enjoy. Why would you imagine this would happen? The magnetic domain is not affected thus, and neither are MOSFETs. You're a mathematical physicist? You're the single least likely person on Earth in my imagine to say "oh, you reduced the speed of some atoms? That must mean magic happens." What could possibly wipe a hard drive from the action of cooling it down? . > Why would heating it back up restore the information? In short form "it doesn't." You may be confusing that some heating processes create damage with the idea that warming something up will harm it. As any schoolchild can tell you, DNA has survived billions of years on this planet, being heated and cooled somewhat rapidly throughout.   > And by the way, thermodynamic irreversibility is related to entropy change, which is a measure of information lost. This is a very "consider a spherical cow" approach to physics. The reason physicists are made fun of on those grounds is that the abstractions they bring to the discussion are frequently so far divorced from the real world situation that by the time you start bringing the real world back to the discussion, their abstractions fall apart. Real world objects that were not designed for durability have not suffered this damage on the timescale of a fifth of the length of the universe. That things are irreversible and related to one another isn't much use when you look at the real world and the things you're describing aren't actually happening at large scale, even in uncontrolled natural conditions. An insect that's been in amber for 500 million years typically has DNA loss on the order of ~5%. It has been exposed to a wild range of temperatures. If you genuinely believe that exposing a hard drive to absolute zero would destroy it, help us understand why Voyager is still running. Maybe it's because it's still a tenth of a degree kelvin above absolute, or something?

rcxdude 5y ago
There's a huge difference between exactly zero and close to it. Space isn't even that close compared to what's been done in a lab, and even in lab experiments the temperatures involved don't correspond to such effects happening.
- JohnHaugeland 5y ago
  Cool story. Did you have an actual explained mechanism by which this is going to happen? Because if you're saying "exactly zero and close to it," we've never actually had a single atom at exactly zero, let alone a macroscopic object
  - aeternum 5y ago
    We can get close enough to absolute zero that very weird quantum effects being to happen which one could argue are associated with information loss. Cooper pairs is one such example, where at very low temperatures electrons pair up and begin to behave like a new combined particle with integer spin. Thus they morph from fermions to bosons which are no longer subject to pauli exclusion and can all occupy the same state. The information required to describe such a system decreases substantially as the potential state space is now quite limited. This manifests in physical phenomenon like superconductivity and superfluidity.
    - JohnHaugeland 5y ago
      We cannot do these things macroscopically, no. I will repeat my protest which you ignored from the previous comment. 1) We have never reduced even a single atom to absolute zero. Practicioners debate whether it's actually possible. 2) Your discussion of bose-einstein condensates is neat and all, but the explicit context is a hard drive. Nobody has ever condensed a macroscopic object (the breathless article about condensing a tardigrade isn't actually correct.) There has never been a superfluid or superconductive hard drive. Please focus on the question being asked, in the context being asked, if you must reply. How do you propose to reduce a hard drive to actual non-almost zero degrees? Not a few particles, not electron pairs. A hard drive. Once it's at absolute zero, formally, so what? Yes, I saw you guys handwaving "spooky stuff happens," but in reality, we've had hard drives within a tenth of a degree kelvin and nothing happened. If you're going to propose effects, please have a specific mechanism in hand that creates the specific effects asked about, in a context that is the hard drive and not two electrons Thanks