Our planet is bathed in a constant flow of energy from the sun and the rest of the universe, which makes life on Earth possible. Sunlight is a type of radiation produced by nuclear reactions in the sun’s core: it’s here, in this phenomenal Vulcan’s forge, that particles of light released from the Sun called photons begin their long journey to the Earth. Travelling at about 300.000 km/s, they cover it in about 8 minutes, a finger snap considering the distance that separates us from our brightest star. Before reaching our comfortable chaise longue on a beach in Santorini, photons will probably have spent hundreds of thousands of years escaping the incandescent Sun’s core[1]. Light and color Visible light- the tiny portion of the electromagnetic spectrum that the human eye can perceive- occurs between 400 and 700 nm[2] (Fig.1). Figure 1. The portion of the electromagnetic spectrum that...