4 ms·

I do hate this stuff, same with Sabine and Carlos, the latter giving me a huge number of lay people that religiously believe in MWI. However, I would say that

I do hate this stuff, same with Sabine and Carlos, the latter giving me a huge number of lay people that religiously believe in MWI. However, I would say that most physicists do believe that quantum fields are the most basic building block of our world, so this isn’t some kind of pop science mess or even a mischaracterisation. Could it be the religion of physicists? Maybe. But it is a widespread one among experts. Physicists generally consider their models to be real rather than just a mental idea that produces the correct results. This kind of thing was controversial in quantum theory until Bells theorem proved that quantum mechanics says things about reality itself (that it is either non local or non deterministic) and PBR theorem proved that the wavefunction is in some sense ontologically real. Now it is less controversial to say that quantum fields are real and the building block of reality

Eupraxias 4y ago
This is an enormous area of study - one that I have followed for a few decades now. The issue comes down to the 'ontological commitment'. Scientists have grown less and less willing to make the ontological commitment. These days, if I ever see it, it shocks me. That's why I'm so interested in this video. What has changed that would make a physicist so confident as to make these kinds of career-breaking ontological commitments? The most excellent book I have read on the topic, and I highly recommend this to everyone on this thread: Arthur Fine "The Shaky Game: Einstein's Realism and the Quantum Theory". I would love to hear suggestions for books to read as follow-up to this.
- bowsamic 4y ago
  > Scientists have grown less and less willing to make the ontological commitment. These days, if I ever see it, it shocks me. I actually think it's the opposite. The PBR theorem even says that the wavefunction is ontological in some sense. People are more willing to make ontological commitments now than they were in the early days of quantum mechanics. > career-breaking ontological commitments It isn't career breaking at all. My boss is literally publishing a paper about how photons ontologically do not exist. Bell's inequalities and things like non-complementarity have a much stronger hold in people's minds due to modern tabletop uses of things like quantum correlations and EPR entanglement. I basically disagree with the premise of your post. I am a postdoc in quantum optics, specialising in high-precision measurements and quantum measurement in general, and I think people are more willing than ever to choose ontological positions on QM.
  - effie 4y ago
    > My boss is literally publishing a paper about how photons ontologically do not exist. I would be interested in this paper. Lamb argued the same, with good intention, but not everybody was impressed.
    - bowsamic 4y ago
      I will try and remember when it is published. The argument is quite strong though in my opinion, basically that photons are simply Fourier-limited modes, so they always deposit energy over a time window according to the uncertainty relation df x dt = pi/4. Also this means they really don't exist as point particles EDIT: Also it of course references Lamb's paper, which I don't think was badly received afaik, just not really widely considered
      - effie 4y ago
        > they always deposit energy over a time window ... Also this means they really don't exist as point particles I am afraid this is already the orthodox view, despite the suggestive/misleading pictures used when teaching particle physics (e.g. Compton's scattering). But even the well-informed photon concept where a photon isn't a point, isn't a plane wave, and usually there is indefinite number of them, is quite horrible. I hope some day the status quo will move where we realize that both the hand wavy imprecise photon talk in textbooks/pop-sci books and the sophist "just a figure of speech when we're talking about quantum field" will be abandoned in favor of more accurate technical terms.
  - Eupraxias 4y ago
    If this is true, then my long wait is over. I am very interested to learn more about any physicist who is willing to make ontological commitments. Ultimately, such a commitment is to realism - what is the epistemological support? I strongly doubt the myriad complexities here have been resolved. Or are you proposing a kind of 'natural ontological attitude'?
    - bowsamic 4y ago
effie 4y ago
> most physicists do believe that quantum fields are the most basic building block of our world Do they? Maybe most theoretical physicists, because that's what they work with, they often are platonists and there is no better model. I doubt the rest, in particular experimental physicists, have even solid one or the other way opinion on this. Ontology is too much philosophy and too little physics.
- bowsamic 4y ago
  They do. Just because it's philosophy and not physics doesn't mean that they don't have a philosophical opinion on it. I agree it's not physics, doesn't mean people don't believe in it
- Eupraxias 4y ago
  Agreed, ontology is philosophy, not physics. It asks, what kinds of things exist? It straddles the line of the empirical and the conceptual, asking, do 'facts' exist, and can there be 'moral facts'? Here be dragons, and epistemology is the treasure. Physics reports observations of experiments and theoretical work, but wisely leaves epistemology to philosophers - a hard learned lesson. Einstein was ridiculed for his ontological realism, and the trend has been in the opposite direction ever since. I am interested in brave physicists who have stood up to the epistemologers, and are willing to make ontological commitments. In my understanding, historically, this attitude poses risks to one's career in physics.

Eupraxias 4y ago

This is an enormous area of study - one that I have followed for a few decades now. The issue comes down to the 'ontological commitment'. Scientists have grown less and less willing to make the ontological commitment. These days, if I ever see it, it shocks me. That's why I'm so interested in this video. What has changed that would make a physicist so confident as to make these kinds of career-breaking ontological commitments? The most excellent book I have read on the topic, and I highly recommend this to everyone on this thread: Arthur Fine "The Shaky Game: Einstein's Realism and the Quantum Theory". I would love to hear suggestions for books to read as follow-up to this.

bowsamic 4y ago
> Scientists have grown less and less willing to make the ontological commitment. These days, if I ever see it, it shocks me. I actually think it's the opposite. The PBR theorem even says that the wavefunction is ontological in some sense. People are more willing to make ontological commitments now than they were in the early days of quantum mechanics. > career-breaking ontological commitments It isn't career breaking at all. My boss is literally publishing a paper about how photons ontologically do not exist. Bell's inequalities and things like non-complementarity have a much stronger hold in people's minds due to modern tabletop uses of things like quantum correlations and EPR entanglement. I basically disagree with the premise of your post. I am a postdoc in quantum optics, specialising in high-precision measurements and quantum measurement in general, and I think people are more willing than ever to choose ontological positions on QM.
- effie 4y ago
  > My boss is literally publishing a paper about how photons ontologically do not exist. I would be interested in this paper. Lamb argued the same, with good intention, but not everybody was impressed.
  - bowsamic 4y ago
    I will try and remember when it is published. The argument is quite strong though in my opinion, basically that photons are simply Fourier-limited modes, so they always deposit energy over a time window according to the uncertainty relation df x dt = pi/4. Also this means they really don't exist as point particles EDIT: Also it of course references Lamb's paper, which I don't think was badly received afaik, just not really widely considered
    - effie 4y ago
      > they always deposit energy over a time window ... Also this means they really don't exist as point particles I am afraid this is already the orthodox view, despite the suggestive/misleading pictures used when teaching particle physics (e.g. Compton's scattering). But even the well-informed photon concept where a photon isn't a point, isn't a plane wave, and usually there is indefinite number of them, is quite horrible. I hope some day the status quo will move where we realize that both the hand wavy imprecise photon talk in textbooks/pop-sci books and the sophist "just a figure of speech when we're talking about quantum field" will be abandoned in favor of more accurate technical terms.
- Eupraxias 4y ago
  If this is true, then my long wait is over. I am very interested to learn more about any physicist who is willing to make ontological commitments. Ultimately, such a commitment is to realism - what is the epistemological support? I strongly doubt the myriad complexities here have been resolved. Or are you proposing a kind of 'natural ontological attitude'?
  - bowsamic 4y ago

effie 4y ago

> most physicists do believe that quantum fields are the most basic building block of our world Do they? Maybe most theoretical physicists, because that's what they work with, they often are platonists and there is no better model. I doubt the rest, in particular experimental physicists, have even solid one or the other way opinion on this. Ontology is too much philosophy and too little physics.

bowsamic 4y ago
They do. Just because it's philosophy and not physics doesn't mean that they don't have a philosophical opinion on it. I agree it's not physics, doesn't mean people don't believe in it
Eupraxias 4y ago
Agreed, ontology is philosophy, not physics. It asks, what kinds of things exist? It straddles the line of the empirical and the conceptual, asking, do 'facts' exist, and can there be 'moral facts'? Here be dragons, and epistemology is the treasure. Physics reports observations of experiments and theoretical work, but wisely leaves epistemology to philosophers - a hard learned lesson. Einstein was ridiculed for his ontological realism, and the trend has been in the opposite direction ever since. I am interested in brave physicists who have stood up to the epistemologers, and are willing to make ontological commitments. In my understanding, historically, this attitude poses risks to one's career in physics.