And in June 1904, after he had read Lorentz's 1904 paper, he noticed the same in relation to length contraction, because at superluminal velocities the factor 1 − v 2 / c 2 {\displaystyle \scriptstyle {\sqrt {1-{v^{2}}/{c^{2}}}}} becomes imaginary.
到了1904年的6月，维恩阅读了洛仑兹1904年发表的论文后，他也注意到这和长度收缩有关，因为在超光速的情况下，系数 1 − v 2 / c 2 {\displaystyle \scriptstyle {\sqrt {1-{v^{2}}/{c^{2}}}}} 会变成一个虚数。