Yahoo 知識+ 將於 2021 年 5 月 4 日 (美國東岸時間) 停止服務,而 Yahoo 知識+ 網站現已轉為僅限瀏覽模式。其他 Yahoo 資產或服務,或你的 Yahoo 帳戶將不會有任何變更。你可以在此服務中心網頁進一步了解 Yahoo 知識+ 停止服務的事宜,以及了解如何下載你的資料。

Light beam,mirror question

If i put a lazer pointer in a vaccum cube and the inner surface of the box is all

mirror.

I turn it on and off it in one second.

Shouldnt the beam be reflecting for unlimited times and the inside of the cube is

bright forever?

*the cube is vaccum

I know it is false but how come... The beam should not lose energy when bouncing off the mirrors in theory?

Thank you very much :/

2 個解答

評分
  • 天同
    Lv 7
    7 年前
    最愛解答

    There is no perfect mirror. On reflection on a surface, part of the incident light energy is reflected, but part of it is absorbed. Hence, the brightness inside the cube would gradually dies down, though this may take a long time on well polished mirror surfaces.

  • 匿名
    7 年前

    這家不錯*****買幾次啦真的一樣

    伴兯单儚仟

還有問題嗎?立即提問即可得到解答。