7 ms·

I would love to hear any critical take on David Tong's excellent video here: https://www.youtube.com/watch?v=zNVQfWC_evg https://www.youtube.com/watch?v=zNVQfWC

I would love to hear any critical take on David Tong's excellent video here: https://www.youtube.com/watch?v=zNVQfWC_evg https://www.youtube.com/watch?v=zNVQfWC_evg "Quantum Fields: The Real Building Blocks of the Universe" I'm interested to talk to others who want to think about QFT past the maths. I had my own stab at making sense of related ontological implications here: http://www.katabane.com/mt/ontology.html#back8 http://www.katabane.com/mt/ontology.html#back8

effie 4y ago
I really detest this kind of peppy proselytizing lecture. It is about mainstream science, but the poor form and lack of respect for the listener is horrible. He is wooing the public a lot with a priest-like confidence on what the world is made of, look how amazing our 12 digit results are, everything is fields, even particles are really fields, even your bodies are fields, we can't really calculate this, it's so hard, but trust us. Matter, universe, big-bang, black holes, Faraday, Maxwell, Einstein, big scary equation, the single greatest equation, bombard and overwhelm the listeners with lots of astonishing statements and make them believe that we are really smart. No experimental rationale for the reality of quantum fields; no mention of the opposing viewpoints of experts such as Schwinger (his source theory), also of large part of particle physics experimenters who tend to think that particles like electrons are real and quantum fields are really just tools that exist in our brains and on paper to predict what happens to these particles. I am afraid this is not teaching people anything of value about physics. It's more about what this group of physicists (high energy theorists) are occupying themselves with.
- bowsamic 4y ago
  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

I really detest this kind of peppy proselytizing lecture. It is about mainstream science, but the poor form and lack of respect for the listener is horrible. He is wooing the public a lot with a priest-like confidence on what the world is made of, look how amazing our 12 digit results are, everything is fields, even particles are really fields, even your bodies are fields, we can't really calculate this, it's so hard, but trust us. Matter, universe, big-bang, black holes, Faraday, Maxwell, Einstein, big scary equation, the single greatest equation, bombard and overwhelm the listeners with lots of astonishing statements and make them believe that we are really smart. No experimental rationale for the reality of quantum fields; no mention of the opposing viewpoints of experts such as Schwinger (his source theory), also of large part of particle physics experimenters who tend to think that particles like electrons are real and quantum fields are really just tools that exist in our brains and on paper to predict what happens to these particles. I am afraid this is not teaching people anything of value about physics. It's more about what this group of physicists (high energy theorists) are occupying themselves with.

bowsamic 4y ago
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