One day I speak with american journalist. He said that when you writing an article for a newspaper or magazine you should imagine your small brother-schoolchild who will read the paper and should understand it. After that he asked me how would I write about «superconductivity». I answered that I would write something like this: «superconductivity — is a phenomenon occuring is some materials at low temperatures characterized by zero electrical resistance». He said that nobody will understand that and you should write this: «Imagine that you have a pipe with water running in it. The pipe in nearly closed by a valve. And then you open the valve at full to let the water go at full stream. That is superconductivity!»
I argued with him that it is not obvious how «water in the pipe» is connected to «superconductivity», I said «everybody knows what is electrical resistance». After that journalist revealed me a secret: the american children does not learn such things as «electrical resistance» in schools!!!
It was a shock to me! Is it true?
P.S. The example with a pipe seems to be incorrect to me. Water has viscosity: if you close the tube with water in a ring then water will stop promptly without a pump. The relaxation time of electrical current in the conductive ring will be T=L/R, where L is the ring electrical inductance, R — its elecrtical resistance (L is analogous to water mass in the pipe, R is analogous to the water viscosity). On the other hand, if you make a ring from superconducting material, the electrical current will never stop! This is because the resistance R is exactly equal to zero in the case of superconductivity! It is quantum effect. It is impossible to imagine it given an example of water in a pipe. That is what I remeber from school...