Tag Archives: Superconductivity

Do We Teach Our Students the Right Physics (Published)

Last night my daughter asked me to explain to her in simple words “why the light changes direction when entering the water”, without complicating the explanation with index here and index there…I said think of the photons or elements of light as balls. At the moment a ball enters the water part of it is inside the water and part of it outside the water. The part that is inside the water experiences different forces than the part outside the water. This is the reason why it changes its direction. It is like when you brake in a car. If the car brakes only work, let say, on the left wheels it changes the direction of the car. She was convinced. Then it was discussion why sometimes teachers have difficulties explaining some problems in physics.

Keywords: Confined Quantum Field Theory, Relativity, Squeeze of photon, Super fluidity, Superconductivity


The present paper is devoted to the investigation of lossless transmission lines terminated by a nonlinear Josephson junction circuit. Such lines are described by a first order hyperbolic system of partial differential equations with sine-nonlinearity. We formulate a mixed problem for this system with nonlinear boundary conditions generated by a nonlinear resistive circuit. In contrast of our previous result [1] here we cannot reduce the mixed problem to an initial value one on the boundary because the hyperbolic system is not linear one. We extend results from [2] and present in an operator form the mixed problem in question. Then we cut off the domain and show that operator defined is contractive one. Its unique fixed point is an approximated solution of the mixed problem.

Keywords: Josephson junction, Nonlinear circuits, Superconductivity, Transmission lines, sine-Gordon equation