相速是觀測速度，是偽速度，群速是真實速度，好像是這個意思

來源: 魯美麗於 2018-11-07 07:03:36 [舊帖] [給我悄悄話] 本文已被閱讀：次

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.