4 ms·

As a physicist, I'm quite used to having to resort to metaphors to convey some ideas to a non-technical audience. If a non-physicist asks me to explain AdS/CFT

As a physicist, I'm quite used to having to resort to metaphors to convey some ideas to a non-technical audience. If a non-physicist asks me to explain AdS/CFT correspondence, I'm not going to be able to explain precisely why the correspondence requires the particular geometry of an anti-de Sitter space to work in a few minutes because the mathematical background required is just too deep. So I don't think metaphor-based explanations are necessarily bad, but I do think they are overused. It's one thing to use a metaphor to convey some essential property of a complex idea to non-experts. It's quite another to see domain experts argue about the (often non-trivial) details of strained metaphors far beyond their area of applicability. Without demeaning the usefulness of metaphors, I'm essentially trying arguing that: 1) domain experts should be far more cognizant of the limitations of the metaphors they employ and 2) domain experts should at the very least try to read the original material before perpetuating solely metaphor-based explanations.

QAPereo 9y ago
Off topic, but can you recommend any resources for getting into the subject of AdS/CFT correspondence? I’m loosely familiar with it, but I’d love more depth. Thanks for any links or hints!
- keldaris 9y ago
  Since you asked for more depth, I'll focus on the (comparatively easier) task of giving some links to technical literature. First of all, if you already have a traditional QFT background, there's the two extremes of either just taking a simple toy example to play with [1] or a fairly rigorous well written lecture course [2]. For a more general physics/math background I'd recommend a slightly more pedagogical treatment [3], but it's still accurate to the subject matter and therefore contains graduate level mathematics. There's a lot more out there, but these are just some of the descriptions I've personally skimmed and found them to be well written and useful. On the other end of the scale, there's a huge amount of popular documentaries out there that purport to say something about AdS/CFT. Most of them either contain nonsense or don't say very much at all. I don't really know how useful the popular analogies really are, but in the spirit of making at least one recommendation that doesn't contain any math, Susskind's public lectures are easy to watch (here's one [4]), and Susskind is careful not to talk nonsense. There isn't really much on AdS/CFT that's in between graduate level mathematics and math-less popular stuff. The reason is that it's a fairly irreducible concept in the sense that you really need to understand what an anti-de Sitter space is and how conformal field theories work to see why there's a mathematical correspondence between them, and this isn't truly analogous to anything simpler. That's why it's very hard to explain beyond the level of vague metaphors without being rigorous about it. [1] https://arxiv.org/pdf/hep-th/0403110.pdf https://arxiv.org/pdf/hep-th/0403110.pdf [2] https://arxiv.org/pdf/hep-th/0201253.pdf https://arxiv.org/pdf/hep-th/0201253.pdf [3] https://arxiv.org/pdf/1310.4319.pdf https://arxiv.org/pdf/1310.4319.pdf [4] https://www.youtube.com/watch?v=2DIl3Hfh9tY https://www.youtube.com/watch?v=2DIl3Hfh9tY
  - QAPereo 9y ago
    This is precisely what I was hoping for, and I just cannot thank you enough for taking the time to do this. I really appreciate you giving me a full range of resources too.
    - keldaris 9y ago
      Glad I could help! AdS/CFT is a very elegant idea in modern physics, I hope you enjoy studying it.
taeric 9y ago
I don't really disagree with your two points. It is the rhetoric of "resort to metaphors" that rings a bell to me. I agree the shared metaphors of notation and common jargon should be preferred as a starting point. I just don't have faith that they are the clear way out of misunderstanding. More, I think it is unrealistic to think this is something that should only be done with "outsiders". Rather, I think we are all using some common language, and shaking up to new language can shake out misunderstandings that were simply not being voiced.

QAPereo 9y ago

Off topic, but can you recommend any resources for getting into the subject of AdS/CFT correspondence? I’m loosely familiar with it, but I’d love more depth. Thanks for any links or hints!

keldaris 9y ago
Since you asked for more depth, I'll focus on the (comparatively easier) task of giving some links to technical literature. First of all, if you already have a traditional QFT background, there's the two extremes of either just taking a simple toy example to play with [1] or a fairly rigorous well written lecture course [2]. For a more general physics/math background I'd recommend a slightly more pedagogical treatment [3], but it's still accurate to the subject matter and therefore contains graduate level mathematics. There's a lot more out there, but these are just some of the descriptions I've personally skimmed and found them to be well written and useful. On the other end of the scale, there's a huge amount of popular documentaries out there that purport to say something about AdS/CFT. Most of them either contain nonsense or don't say very much at all. I don't really know how useful the popular analogies really are, but in the spirit of making at least one recommendation that doesn't contain any math, Susskind's public lectures are easy to watch (here's one [4]), and Susskind is careful not to talk nonsense. There isn't really much on AdS/CFT that's in between graduate level mathematics and math-less popular stuff. The reason is that it's a fairly irreducible concept in the sense that you really need to understand what an anti-de Sitter space is and how conformal field theories work to see why there's a mathematical correspondence between them, and this isn't truly analogous to anything simpler. That's why it's very hard to explain beyond the level of vague metaphors without being rigorous about it. [1] https://arxiv.org/pdf/hep-th/0403110.pdf https://arxiv.org/pdf/hep-th/0403110.pdf [2] https://arxiv.org/pdf/hep-th/0201253.pdf https://arxiv.org/pdf/hep-th/0201253.pdf [3] https://arxiv.org/pdf/1310.4319.pdf https://arxiv.org/pdf/1310.4319.pdf [4] https://www.youtube.com/watch?v=2DIl3Hfh9tY https://www.youtube.com/watch?v=2DIl3Hfh9tY
- QAPereo 9y ago
  This is precisely what I was hoping for, and I just cannot thank you enough for taking the time to do this. I really appreciate you giving me a full range of resources too.
  - keldaris 9y ago
    Glad I could help! AdS/CFT is a very elegant idea in modern physics, I hope you enjoy studying it.

taeric 9y ago

I don't really disagree with your two points. It is the rhetoric of "resort to metaphors" that rings a bell to me. I agree the shared metaphors of notation and common jargon should be preferred as a starting point. I just don't have faith that they are the clear way out of misunderstanding. More, I think it is unrealistic to think this is something that should only be done with "outsiders". Rather, I think we are all using some common language, and shaking up to new language can shake out misunderstandings that were simply not being voiced.