Did you know Korea has an ancient bronze mirror with incredibly precise patterns?
Korea is one of the leading providers of semiconductors in the world and is leading the global semiconductor technology in the 21st century. Samsung Electronics, the global semiconductor leader, found an ancient mold for bronze casting during its ground preparation for a semiconductor plant in the city of Yongin in Gyeonggido Province.
This mold was used to cast bronze mirrors like Korean National Treasure #141 Danyusemungyeong (bronze mirror with fine geometric patterns). The ancient mirror, also known as a fine-lined mirror, was cast around 4th century B.C. The rear of the 8.3-inch-diameter mirror is adorned with 13,300 concentric circles of 0.001 inches. The lines are in micron size, which is difficult to replicate even with today’s nanotechnology.
The microscope was invented in the late 16th century in Europe. It is a mystery how the people of Gojoseon(2333–108 B.C.) cast such microscopic lines on the mirror in the prehistoric period. The ancient bronze mirror shows evidence of the advanced scientific technology that the first Korean kingdom of Gojoseon possessed.