In a book focusing, as this does, on symmetry, it seems misleading not to explain the fundamental principle that all interaction follows from symmetry: the gauge principle of London and Weyl, modelled on and foreshadowed by Einstein's derivation of gravity from general relativity (Einstein seems to be at the root of everything). The beautiful idea that every continuous symmetry implies a conservation law, and an accompanying interaction between the conserved charges, determines the structure of all of the interactions of physics. It is not appropriate to try to approach advanced topics such as electroweak unification and supersymmetry without this foundation block.To see how this plays out in electrodynamics see here.
Thursday, September 26, 2019
Symmetry is the origin of all interactions
In Phil Anderson's review of Lucifer's Legacy: The Meaning of Asymmetry by Frank Close, Anderson makes the following profound and cryptic comment.
Subscribe to:
Post Comments (Atom)
What is your experience of using AI for research in condensed matter theory?
I have been dabbling a little with using AI (at a very basic level) to help me with some research problems. For example, in a recent prepr...
-
This week Nobel Prizes will be announced. I have not done predictions since 2020 . This is a fun exercise. It is also good to reflect on w... -
The Ising model is a paradigm in both statistical mechanics and condensed matter physics. Today for most theorists it is so familiar that so... -
Some of my colleagues and I have started an interesting discussion about how to teach quantum theory to undergraduates. We have courses in t...
I can't help but wonder if this idea is backwards. Is it more that as physicists we can *only* make sense of interactions in terms of symmetry? It doesn't seem that symmetry plays nearly such a decisive role in biological interactions for example.
ReplyDeleteGood point. This perspective is a ``fundamental'' one. Van der Waals interactions arise from quantum fluctuations in the Coulomb interaction. The latter arises from the U(1) gauge invariance of electromagnetism.
DeleteHi Ross, I am sure you have thought about this, and come farther than I. I don't "understand" how symmetry breaking leads to interacting theories. Sure, I have applied the gauge transformations, and saw how the couplings emerged in the Lagrangian. Unfortunately, that does not give me any feel of what is happening. The situation is different for VdW forces, where you can understand the force emerging from fluctuating charges. Are we even talking about the same sort of emerging? Cheers,--stijn
ReplyDeleteSeems odd for Anderson not to mention Noether in there. Her eponymous theorem certainly predated London's work, and I think also Weyl's.
ReplyDelete