Physics and Beyond "'Do you see whales, Heisenberg?', 'Yes, I see only whales, but I hope they are only big waves.'", is one of humorous scenes when the author, Bohr and other friends were sailing in a dark night. The book provides a first-hand account about how science is done and how quantum physics, especially the Copenhagen interpretation, emerged. "Nobody can reproduce these conversations verbatim, but I believe that the spirit of what the people said, and how they did, is conserved," the author tries to explain in the preface. Many believe that the golden years of physics around 1925, when "even small
Heisenberg model (quantum) Assuming that there's only one critical point, we can conclude that the phase transition happens at formula_22. It is common to name the model depending on the values of formula_23, formula_24 and formula_6: if formula_26, the model is called the Heisenberg XYZ model; in the case of formula_27, it is the Heisenberg XXZ model; if formula_28, it is the Heisenberg XXX model. The spin 1/2 Heisenberg model in one dimension may be solved exactly using the Bethe ansatz. In the algebraic formulation, these are related to particular Quantum affine algebras and Elliptic Quantum Group in the XXZ and XYZ cases