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> And yet I can speak concretely about a hydrogen atom You can talk about some abstractions about how a hydrogen atom works, but we don't fully understand ever

> And yet I can speak concretely about a hydrogen atom You can talk about some abstractions about how a hydrogen atom works, but we don't fully understand everything about atomic structure. We don't know if there is something that makes up the structures of subatomic particles becuase we don't have particle accelerators that have enough energy for us to peer deeper into what quarks are made up of. We don't even know if we've found all the types of particles.

Robotbeat 5y ago
Actually, we do fully understand everything about the atomic structure of the hydrogen atom, everything relevant to chemistry and how life (for instance) works. If we have not yet unified the fundamental forces, that doesn't mean we don't have an INCREDIBLY detailed and complete understanding of the hydrogen atom. Corner cases in several layers lower than chemistry vs not even really knowing where a memory is stored!
- Supermancho 5y ago
  > Actually, we do fully understand everything about the atomic structure of the hydrogen atom, Not sure where that hubris comes from. There are physical phenomena we have not been able to test, so there will always be unknowns and assumptions based on (abstract) modeling. eg the metallic liquid hydrogen described here https://edu.rsc.org/soundbite/hydrogen-falls-apart-under-pressure/2000532.article https://edu.rsc.org/soundbite/hydrogen-falls-apart-under-pre...
  - Robotbeat 5y ago
    It comes from the unreasonable effectiveness of quantum electrodynamics. That we predicted a metallic state of hydrogen (a sort of molecular, not atomic, structure) under an extreme corner case (extreme pressure) over 80 years ago (well before it could be experimentally verified) just highlights what I mean. And I don’t mean to say that neuroscientists are doing shoddy work. Far from it! The brain is a far more complex entity than RNA or a hydrogen atom. The task is MUCH harder! But I am showing that high level of specific, concrete knowledge IS possible in the physical sciences. Memory in the Brain is a physical process as well, but we have only a relatively vague understanding of the specifics of it. We can sequence DNA or RNA accurately with relative ease. We cannot do the same with memories in the brain.
    - Supermancho 5y ago
      > That we predicted a metallic state of hydrogen You're missing the point. The idea that the predictions are the same as knowledge illustrates the misunderstanding. We do not know because we cannot prove it. I shouldn't need to get into the reason we produce experimental evidence eg https://www.forbes.com/sites/startswithabang/2019/07/06/ask-ethan-why-do-gravitational-waves-travel-exactly-at-the-speed-of-light/?sh=740247ee32dc https://www.forbes.com/sites/startswithabang/2019/07/06/ask-... - via the LIGO and Virgo detectors
      - d110af5ccf 5y ago
        @Robotbeat isn't the one missing the point here. The incredible accuracy of those predictions serves as a testament to just how well we do understand that particular phenomenon. Now compare to neuroscience, where we struggle to accurately make (by comparison) the most basic of predictions.
        Supermancho 5y ago
        > Now compare to neuroscience, where we struggle to accurately make (by comparison) the most basic of predictions. I'm not addressing the hand wavy nature of the article, which is self-evident. This is irrelevant to the point being discussed.
        d110af5ccf 5y ago
        > This is irrelevant to the point being discussed. You might want to reread the thread for context. You don't seem to be discussing the same point as the people you're replying to.
- monocasa 5y ago
  Quantum chemistry is a field with a lot of unknowns still. To say that chemistry has a complete understanding of the hydrogen atom is inaccurate.
  - d110af5ccf 5y ago
    ... what?! We can accurately predict hydrogen (and helium!) energy characteristics to _absurd_ accuracy levels. The issue is that even a system as simple as a single helium atom is prohibitively computationally expensive.
    - monocasa 5y ago
      There's more to quantum chemistry (and hydrogen atoms) than what you're saying. If you define chemistry tautologically as what we know, then sure I guess.
      - d110af5ccf 5y ago
        To be clear, I'm not disputing unknowns in quantum chemistry in general (I lack the requisite background). But I was definitely of the understanding that single atom (and possibly somewhat larger) systems are thoroughly understood from a mathematical perspective at this point. I would appreciate concrete examples of open questions, either for hydrogen atoms specifically or for quantum chemistry more generally.

Robotbeat 5y ago

Actually, we do fully understand everything about the atomic structure of the hydrogen atom, everything relevant to chemistry and how life (for instance) works. If we have not yet unified the fundamental forces, that doesn't mean we don't have an INCREDIBLY detailed and complete understanding of the hydrogen atom. Corner cases in several layers lower than chemistry vs not even really knowing where a memory is stored!

Supermancho 5y ago
> Actually, we do fully understand everything about the atomic structure of the hydrogen atom, Not sure where that hubris comes from. There are physical phenomena we have not been able to test, so there will always be unknowns and assumptions based on (abstract) modeling. eg the metallic liquid hydrogen described here https://edu.rsc.org/soundbite/hydrogen-falls-apart-under-pressure/2000532.article https://edu.rsc.org/soundbite/hydrogen-falls-apart-under-pre...
- Robotbeat 5y ago
  It comes from the unreasonable effectiveness of quantum electrodynamics. That we predicted a metallic state of hydrogen (a sort of molecular, not atomic, structure) under an extreme corner case (extreme pressure) over 80 years ago (well before it could be experimentally verified) just highlights what I mean. And I don’t mean to say that neuroscientists are doing shoddy work. Far from it! The brain is a far more complex entity than RNA or a hydrogen atom. The task is MUCH harder! But I am showing that high level of specific, concrete knowledge IS possible in the physical sciences. Memory in the Brain is a physical process as well, but we have only a relatively vague understanding of the specifics of it. We can sequence DNA or RNA accurately with relative ease. We cannot do the same with memories in the brain.
  - Supermancho 5y ago
    > That we predicted a metallic state of hydrogen You're missing the point. The idea that the predictions are the same as knowledge illustrates the misunderstanding. We do not know because we cannot prove it. I shouldn't need to get into the reason we produce experimental evidence eg https://www.forbes.com/sites/startswithabang/2019/07/06/ask-ethan-why-do-gravitational-waves-travel-exactly-at-the-speed-of-light/?sh=740247ee32dc https://www.forbes.com/sites/startswithabang/2019/07/06/ask-... - via the LIGO and Virgo detectors
    - d110af5ccf 5y ago
      @Robotbeat isn't the one missing the point here. The incredible accuracy of those predictions serves as a testament to just how well we do understand that particular phenomenon. Now compare to neuroscience, where we struggle to accurately make (by comparison) the most basic of predictions.
      - Supermancho 5y ago
        > Now compare to neuroscience, where we struggle to accurately make (by comparison) the most basic of predictions. I'm not addressing the hand wavy nature of the article, which is self-evident. This is irrelevant to the point being discussed.
        d110af5ccf 5y ago
        > This is irrelevant to the point being discussed. You might want to reread the thread for context. You don't seem to be discussing the same point as the people you're replying to.
monocasa 5y ago
Quantum chemistry is a field with a lot of unknowns still. To say that chemistry has a complete understanding of the hydrogen atom is inaccurate.
- d110af5ccf 5y ago
  ... what?! We can accurately predict hydrogen (and helium!) energy characteristics to _absurd_ accuracy levels. The issue is that even a system as simple as a single helium atom is prohibitively computationally expensive.
  - monocasa 5y ago
    There's more to quantum chemistry (and hydrogen atoms) than what you're saying. If you define chemistry tautologically as what we know, then sure I guess.
    - d110af5ccf 5y ago
      To be clear, I'm not disputing unknowns in quantum chemistry in general (I lack the requisite background). But I was definitely of the understanding that single atom (and possibly somewhat larger) systems are thoroughly understood from a mathematical perspective at this point. I would appreciate concrete examples of open questions, either for hydrogen atoms specifically or for quantum chemistry more generally.