Light is the source of vision; without it we can’t see a thing. Light is the key to technology; it’s how we can talk to someone halfway around the world without so much as a second’s delay because light can circle the globe seven and a half times a second.2 Light is the first link in the food chain; no photosynthesis equals no food. Light is the basis of health; the absence of light causes everything from vitamin D deficiency to depression. Light is the origin of energy; in Einstein’s equation E = MC2, energy (E) is defined as mass (M) times the speed of light (C) squared. The speed of light
...more
