波的反射与折射、干涉与繞射都很容易藉水面上的波紋演示出來。為了產生這種水面波,先製備一個水盤,它的木框的尺寸為60厘米×60厘米,框的邊緣是倾斜的,盤底则是玻璃的。圖1表示出盤和它投在幕上的影子。倾斜的框邊能吸收傳來的水波,減少它的反射,以免它擾亂盤中的實驗。在盤框的一邊中間,緊夾在兩個木塊當中的鋼片(鉗工底鋸條之類的 Wave reflection and refraction, interference and diffraction are easily demonstrated by the ripples on the water surface. To create this surface wave, a water tray is first prepared, the dimensions of which are 60 cm by 60 cm, the edges of the frame are beveled, and the bottom of the tray is glass. Figure 1 shows the disk and its shadow cast on the screen. The sloping edge of the frame absorbs water and reduces its reflections, lest it disturb the experiment in the dish. In the middle of one side of the disk frame, the steel plate (the clamp bottom saw blade and the like)