translation.en: You won't be surprised to hear that if I take this circular magnet, in which the magnetic field is the same all around, the superconductor will be able to freely rotate around the axis of the magnet.
translation.zh: 如果我拿出这样一个环形磁铁， 你们就不会感到惊讶， 在这个环形磁铁里，各处的磁场是相同的， 超导体能够绕着磁铁的轴线自由旋转。