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 picture line above is the Heisenberg Hamiltonian "H"("t"), which may differ from the Schrödinger Hamiltonian. An important special case of the equation above is obtained if the Hamiltonian does not vary with time. Then the time-evolution operator can be written as Therefore, and, Here ∂"A"/∂"t" is the time derivative of the initial "A", not the "A"("t") operator defined. The last equation holds since commutes with . If the Hamiltonian does not vary with time, then the time-evolution operator can be written as where is the Hamiltonian and is the reduced Planck constant. Therefore, Thus and hence emerges the above Heisenberg equation