  The reason why high temperature superconductivity has been being debated is
that many basic ideas in literatures are wrong. This work shows that the
magnetic flux quantum in a superconducting ring have been inaccurately
explained in fact, thus we suggest a reinterpretation of the magnetic flux
quantum in a superconducting ring on the basis of the translations of pairs. We
also predict that the internal and external surface of a superconducting tube
have the reverse circling supercurrents. This means that a more thick tube
could trap a larger amount of flux. Both the magnetic flux quantum and the
reverse circling supercurrents could not be found with the London equation.
