记得曾在一个风沙弥空夕阳西下的春日里,我在北京西郊田间路上散步。偶一抬头,望见依傍西山的夕阳是白色的。我不禁脱口而出:“白日依山尽”。啊,“白日”原来如此。我看过一些唐诗的选本,但没有见过对“白日”的正面解释。多少年来,我一直思索“依山尽”的太阳,为什么是白色的?然而却没找到满意的答案。没想到今天偶然得之,真是“无心插柳柳成荫”了。我一直目送着“白日”徐徐依山而尽。为了验证偶然是不是必然,我又选择过几个风尘满天的日子去看落日,果然夕阳是白色的。从光学的角度出发,也可以解释通风沙中的夕阳是白色的。 I remember that in a spring day when the wind was blowing in the sand, I walked on the field in the western suburbs of Beijing. Even when I looked up, I saw that the setting sun on the west side of Mount Yi was white. I can’t help but blurt out: “I do my best in the sky.” Ah, this is what happened on the “day”. I have read some of the Tang poetry, but I have not seen a positive explanation of “white day.” For many years, I have been thinking about the sun that is “doing everything in the mountains”. Why is it white? However, I have not found a satisfactory answer. I did not expect to get it by chance today. It was really “unintentional.” I have always watched the “white day” slowly down the mountain. In order to verify that chance was not inevitable, I chose to go through several dusty days to see the setting sun, and surely the setting sun was white. From an optical point of view, it can also explain that the sunset in the ventilated sand is white.