This is the Goron Lighthouse, built in the 14th century, and has guarded every ship passed by more than 400 years.

This is the flash of our mobile phone. The earliest appeared in 2006, and the beauty of billions of young ladies was illuminated for more than ten years.

Although the two seem to have no connection, their appearance is inseparable from a person, French physicist Fresnel.

你手机闪光灯的历史,比手机还长?

Lighthouse, as a sign of navigation civilization, and common materials for elementary composition. Its appearance is very ribbon.

Before, the ancients provided fishermen with whale oil flames. Subsequently, although the light of the lighthouse was getting brighter from the whale flames to the Algalus lamp to the electric light, the light of the lighthouse could not be solved.

你手机闪光灯的历史,比手机还长?

Ordinary lenses are also unable to afford the high cost and heavy weight.

Until 1832, the Fresnel lens with concentric circular lines was first installed on the Goboy Lighthouse. This lens is not only thin and light, but also makes the lighting distance of the lighthouse soaring directly to 32 kilometers, becoming the standard of the lighthouse backward.

The circle pattern on the mobile phone flash is the Fresnel lens. In addition, there are SLR lenses, VR glasses, etc.

你手机闪光灯的历史,比手机还长?

Maybe Fresnel himself would not think that after more than two hundred years, although the lighthouse had gradually eliminated the Fresnel lens, it walked into every smartphone from the vast sea and continued to shine. This is the product of tomorrow’s product. Essence