12楼: Originally posted by sciencejoy at 2015-01-28 08:47:49
群速度当然可以超光速，只是没有相速度超光速那么常见...

21楼: Originally posted by metaliium at 2015-01-29 01:04:49
那您给个例子吧，以前哪篇文献介绍了一个群速度超光速的实验观测。。。

大家可以学习学习...

6楼: Originally posted by sky_walker at 2015-01-27 22:10:09
看了一下摘要，有这么一句话：
“However, light beams have finite transverse size, which leads to a modification of their wavevectors resulting in a change to their phase and group velocities.”
为什 ...