That light dictates our everyday lives is unquestionable. The day is defined by the Sun light, at night we turn on the lamps, we have all become instant photographers, and we connect to each other with video calls.
But does everyone know what light is? The most adventurers will enter the wave-particle discussion. Others will say light is a positive glowing energy. Prof. Eric Potma guided us through the history of light as a concept until the word “photon” was coined, which funny enough was not to define light. Eric started the journey in the ancient Greece, when Leucippus considered light as particles, idea that was vastly ignored until centuries later. He then discussed the origin of light: were the objects emitting it, or were our eyes, as Plato sustained? With the introduction of the light ray concept from Euclide and Diocles, we started to suspect that light was something independent of our own eyes. Eric explained to us the Archimedes mirror, which might have been used to burn down roman vessels by creating heat rays. You can find out if this is a myth in this episode of the Myth-busters. We then travelled forward in time with Alhazen contribtions, Zacharias Janssen’s microscope, Newton, Huygens and Maxwell’s theories, all the way to Einstein’s points of view and Lewis naming. Today, a photon is considered to be the elementary unit of light, or quanta of light, as Einstein and Planck referred to.
Donn Silberman was our second invited speaker. He provided a detailed explanation on why we are celebrating the International Year of Light, you can find facts, figures, and all the activities around the Globe in the official website. Light impacts so many areas of our lives that it is important to be aware of what is being done with it and what possibilities it offers. Donn also emphasized the excellent light-based research that is being done at UC Irvine.