10 ms·

I figured this article would fly over my head (which it mostly did), but it was actually a very fun read. My main takeaway was the paradox that the interesting

I figured this article would fly over my head (which it mostly did), but it was actually a very fun read. My main takeaway was the paradox that the interesting arrangement of matter could be in its lowest energy state, yet still moving. And that no energy could be extracted from this movement. I'm probably butchering the concept with my misuse of terminology but whatevs.

deleted 10y ago
[deleted]
lisper 10y ago
You're not that far off. The particles aren't really moving, i.e. they are not going from one spatial location to another. What is happening is that they are changing quantum spin states, and the spin states are changing in such a way that it appears that a circular arrangement of atoms is rotating. This is a reflection of the fact that an atom isn't really a thing (there are no "things", i.e. there are no particles) it's just a quantum state, so if you have a quantum system A in state 1 and system B in state 2, and system A transitions to state 2 and system B transitions to state 1 then this end result is indistinguishable from the two systems having swapped locations. We call this "moving" because classical motion is the only mechanism we're familiar with in everyday life that allows two systems to swap locations. But that kind of moving is not what is happening here.
- Jcol1 10y ago
  Isn't the entire universe one quantum system? If so, how can we talk about discrete systems. Also, when you say there are not discrete things, do you mean in the QFT sense of field excitations?
  - lisper 10y ago
    > Isn't the entire universe one quantum system? Yes. > If so, how can we talk about discrete systems. That is an excellent question! And the answer is that when you do the math, the result of taking a subset of the wave function (the mathematical operation is called a "trace") is something that looks like a classical system. If you want the details, see this paper: http://www.flownet.com/ron/QM.pdf http://www.flownet.com/ron/QM.pdf Or this video https://www.youtube.com/watch?v=dEaecUuEqfc https://www.youtube.com/watch?v=dEaecUuEqfc which covers the same material.
    - nickpsecurity 10y ago
      " And the answer is that when you do the math, the result of taking a subset of the wave function (the mathematical operation is called a "trace") is something that looks like a classical system." Your statement just connected to unrelated subjects in my head that might mean something. As I studied hardware, I found that underneath these nice, mathematical blocks that we build digital with are analog components that appear to operate on messy, kind-of-chaotic waves of electricity they hand-tune into the digital cells. Then, you say the clean building blocks of classical systems are composed of messy waves in quantum. Worded like that, it makes me wonder if analog vs digital could teach us something about quantum vs classical. Or some universal principle at work. Reason I wonder is some of the math keeps showing up in different disciplines. What you think? Is my brain overreaching on this?
      - lisper 10y ago
        The difference between classical and quantum is not really analogous to the difference between digital and analog, it's the difference between real numbers and Turing machines (classical) and complex numbers (quantum). But the ability of classical math to model all this is truly extraordinary. https://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html https://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.htm...
        nickpsecurity 10y ago
        Oh OK. Yeah, I assumed quantum did reals for probabilities. Might not apply if using complex numbers.
        lisper 10y ago
        Probabilities are always real (by definition). QM uses complex numbers for amplitudes, not probabilities. The probability is the square of the absolute value of the amplitude. Why nature should choose such a weird rule is the Big Mystery. The best discussion of this that I know of is this one: http://www.scottaaronson.com/democritus/lec9.html http://www.scottaaronson.com/democritus/lec9.html
- davesque 10y ago
  Thanks for the great explanation. Serious question: Can I ask how you happen to know so much about this subject?
  - lisper 10y ago
    Years of practice :-) Seriously though, I don't actually know much about QM, I only know the One Thing that makes the rest of QM easy to understand (kind of like knowing Lisp makes the rest of computer programming easy to understand). In case you want to know that One Thing, it's written up here: http://www.flownet.com/ron/QM.pdf http://www.flownet.com/ron/QM.pdf There's also a movie version: https://www.youtube.com/watch?v=dEaecUuEqfc https://www.youtube.com/watch?v=dEaecUuEqfc
    - davesque 10y ago
      Cool, thanks for the info.
      - selimthegrim 10y ago
        You may want to also look for an article by N. David Mermin "Is the moon there when nobody looks"
    - jasonwatkinspdx 10y ago
      Just be aware that while Dr. Garret is very smart (and very accomplished with software) he is not a physicist. When this talk first came out I asked a couple people who do know QFT in detail about it and they were quite dismissive.
      - lisper 10y ago
        It's true. I'm not a physicist. I have never claimed to be a physicist. The only contribution I have ever claimed is a pedagogical one. When I first wrote the paper 15 years ago I submitted it to Physics Today. It was rejected, not because it was wrong, but because the reviewers thought that it was nothing new, that everyone already knew this stuff. Since then the physics community has bifurcated rather neatly into two camps: the ones who agree with the PT reviewers, and the ones who think I'm a "category 5 loon" (that was Lubos Motl's term). Personally, I think the existence of people like Motl and your anonymous "dismissive" QFT experts -- and the fact that I can still stump card-carrying physicists with the EPRG paradox -- falsifies the hypothesis that "everyone already knows this stuff." I will also say, because I'm feeling rather annoying by all this, that in 15 years no one has ever pointed out any actual mistakes in the paper (except for a few typos).
- bcherny 10y ago
  This interpretation sounds similar to Ulam/Wolfram's cellular automata :)
- ams6110 10y ago
  Sounds almost like how words appear to be moving across a scrolling led (or previously, incandescent bulb) display, when nothing is moving it's just each led/bulb switching from lit to unlit.
  - lisper 10y ago
    That is (almost) exactly right. The only difference is that with classical states it is possible to distinguish between the object (the light bulb) and the state (on or off). With quantum systems the object is the state, so there is no way to distinguish between "the same atom" and "different atoms with the same state".
    - PetahNZ 10y ago
      So if these are just states turning on and off, can we turn the state to on in multiple places at the same time?
    - zer0gravity 10y ago
      So by saying this, you're actually saying that we're living in some sort of state machine / cellular automata universe, and in order to understand it, we just have to find the rules of interaction/propagation of the states ?
      - lisper 10y ago
        No, we are living in a quantum universe (or a quantum multiverse if you prefer). We don't yet know whether space and time are discrete, because we have not yet unified QM and relativity. If space and time turn out to be discrete then yes, the multiverse would be essentially a cellular automaton. But if they aren't then it (probably) isn't.
        zer0gravity 10y ago
        But "quantum universe" doesn't actually mean that we're working with quanta(s), which translates to infinitesimally small but discrete quantities ? Aren't Planck constants all about that ?
- omginternets 10y ago
  Where does the "time" part come in?
  - lisper 10y ago
    Mainly in the marketing. If it were called "ground-state quantum resonance" (which is what it is) no one would care.

deleted 10y ago

[deleted]

lisper 10y ago

You're not that far off. The particles aren't really moving, i.e. they are not going from one spatial location to another. What is happening is that they are changing quantum spin states, and the spin states are changing in such a way that it appears that a circular arrangement of atoms is rotating. This is a reflection of the fact that an atom isn't really a thing (there are no "things", i.e. there are no particles) it's just a quantum state, so if you have a quantum system A in state 1 and system B in state 2, and system A transitions to state 2 and system B transitions to state 1 then this end result is indistinguishable from the two systems having swapped locations. We call this "moving" because classical motion is the only mechanism we're familiar with in everyday life that allows two systems to swap locations. But that kind of moving is not what is happening here.

Jcol1 10y ago
Isn't the entire universe one quantum system? If so, how can we talk about discrete systems. Also, when you say there are not discrete things, do you mean in the QFT sense of field excitations?
- lisper 10y ago
  > Isn't the entire universe one quantum system? Yes. > If so, how can we talk about discrete systems. That is an excellent question! And the answer is that when you do the math, the result of taking a subset of the wave function (the mathematical operation is called a "trace") is something that looks like a classical system. If you want the details, see this paper: http://www.flownet.com/ron/QM.pdf http://www.flownet.com/ron/QM.pdf Or this video https://www.youtube.com/watch?v=dEaecUuEqfc https://www.youtube.com/watch?v=dEaecUuEqfc which covers the same material.
  - nickpsecurity 10y ago
    " And the answer is that when you do the math, the result of taking a subset of the wave function (the mathematical operation is called a "trace") is something that looks like a classical system." Your statement just connected to unrelated subjects in my head that might mean something. As I studied hardware, I found that underneath these nice, mathematical blocks that we build digital with are analog components that appear to operate on messy, kind-of-chaotic waves of electricity they hand-tune into the digital cells. Then, you say the clean building blocks of classical systems are composed of messy waves in quantum. Worded like that, it makes me wonder if analog vs digital could teach us something about quantum vs classical. Or some universal principle at work. Reason I wonder is some of the math keeps showing up in different disciplines. What you think? Is my brain overreaching on this?
    - lisper 10y ago
      The difference between classical and quantum is not really analogous to the difference between digital and analog, it's the difference between real numbers and Turing machines (classical) and complex numbers (quantum). But the ability of classical math to model all this is truly extraordinary. https://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html https://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.htm...
      - nickpsecurity 10y ago
        Oh OK. Yeah, I assumed quantum did reals for probabilities. Might not apply if using complex numbers.
        lisper 10y ago
        Probabilities are always real (by definition). QM uses complex numbers for amplitudes, not probabilities. The probability is the square of the absolute value of the amplitude. Why nature should choose such a weird rule is the Big Mystery. The best discussion of this that I know of is this one: http://www.scottaaronson.com/democritus/lec9.html http://www.scottaaronson.com/democritus/lec9.html
davesque 10y ago
Thanks for the great explanation. Serious question: Can I ask how you happen to know so much about this subject?
- lisper 10y ago
  Years of practice :-) Seriously though, I don't actually know much about QM, I only know the One Thing that makes the rest of QM easy to understand (kind of like knowing Lisp makes the rest of computer programming easy to understand). In case you want to know that One Thing, it's written up here: http://www.flownet.com/ron/QM.pdf http://www.flownet.com/ron/QM.pdf There's also a movie version: https://www.youtube.com/watch?v=dEaecUuEqfc https://www.youtube.com/watch?v=dEaecUuEqfc
  - davesque 10y ago
    Cool, thanks for the info.
    - selimthegrim 10y ago
      You may want to also look for an article by N. David Mermin "Is the moon there when nobody looks"
  - jasonwatkinspdx 10y ago
    Just be aware that while Dr. Garret is very smart (and very accomplished with software) he is not a physicist. When this talk first came out I asked a couple people who do know QFT in detail about it and they were quite dismissive.
    - lisper 10y ago
      It's true. I'm not a physicist. I have never claimed to be a physicist. The only contribution I have ever claimed is a pedagogical one. When I first wrote the paper 15 years ago I submitted it to Physics Today. It was rejected, not because it was wrong, but because the reviewers thought that it was nothing new, that everyone already knew this stuff. Since then the physics community has bifurcated rather neatly into two camps: the ones who agree with the PT reviewers, and the ones who think I'm a "category 5 loon" (that was Lubos Motl's term). Personally, I think the existence of people like Motl and your anonymous "dismissive" QFT experts -- and the fact that I can still stump card-carrying physicists with the EPRG paradox -- falsifies the hypothesis that "everyone already knows this stuff." I will also say, because I'm feeling rather annoying by all this, that in 15 years no one has ever pointed out any actual mistakes in the paper (except for a few typos).
bcherny 10y ago
This interpretation sounds similar to Ulam/Wolfram's cellular automata :)
ams6110 10y ago
Sounds almost like how words appear to be moving across a scrolling led (or previously, incandescent bulb) display, when nothing is moving it's just each led/bulb switching from lit to unlit.
- lisper 10y ago
  That is (almost) exactly right. The only difference is that with classical states it is possible to distinguish between the object (the light bulb) and the state (on or off). With quantum systems the object is the state, so there is no way to distinguish between "the same atom" and "different atoms with the same state".
  - PetahNZ 10y ago
    So if these are just states turning on and off, can we turn the state to on in multiple places at the same time?
  - zer0gravity 10y ago
    So by saying this, you're actually saying that we're living in some sort of state machine / cellular automata universe, and in order to understand it, we just have to find the rules of interaction/propagation of the states ?
    - lisper 10y ago
      No, we are living in a quantum universe (or a quantum multiverse if you prefer). We don't yet know whether space and time are discrete, because we have not yet unified QM and relativity. If space and time turn out to be discrete then yes, the multiverse would be essentially a cellular automaton. But if they aren't then it (probably) isn't.
      - zer0gravity 10y ago
        But "quantum universe" doesn't actually mean that we're working with quanta(s), which translates to infinitesimally small but discrete quantities ? Aren't Planck constants all about that ?
omginternets 10y ago
Where does the "time" part come in?
- lisper 10y ago
  Mainly in the marketing. If it were called "ground-state quantum resonance" (which is what it is) no one would care.