我们的祖先很早就懂得利用光滑平面观察自己的形象,最早利用的是水平面.5000多年前,我们祖先发明了炼铜技术.在商朝,青铜器的冶炼和铸造达到了很高水平.人们发现,铜盆的光滑底面比较容易反光,可以照出清晰的头像,于是人们把铜盆周围多余部分去掉,构成了铜面镜.后来人们开始直接铸造铜面镜,并且设法把镜面磨得十分光滑,真可谓光彩照人. Our ancestors knew early on how to use a smooth plane to observe their own image. The earliest use was in the water level. More than 5,000 years ago, our ancestors invented the copper smelting technique. In the Shang dynasty, the smelting and casting of bronze wares reached a very high level. The smooth bottom of the copper basin is relatively easy to reflect, and it can illuminate a clear avatar, so people remove the excess part around the copper basin to form a copper mirror. Later, people began to directly cast copper mirrors and managed to smooth the mirror surface. It’s really brilliant.