Most of us rarely think about light since it is a constant presence in our lives – from the abundant rays of sunshine during a morning commute, to the bulbs that illuminate a darkened room with the flip of a switch, to the dancing red lines of a supermarket checkout scanner. But light is one of the most important resources in the universe, powering everything from photosynthesis to x-ray machines. To highlight the importance of light in our modern lives, the United Nations declared 2015 the International Year of Light and Light-Based Technologies. Through a variety of educational programs via partner organizations, the International Year of Light (IYL) seeks to promote public and political understanding of how central light and light-based technologies are to the modern world.
Light is a form of energy. The light we see everyday is only a small portion of what is actually present, since light wavelengths range across a spectrum from the very short (gamma rays) to the very long (radio waves). Visible light takes up only a tiny portion in the middle of the spectrum (see our Light & Electromagnetism module for more info). Wavelengths are one way of thinking about light, but it can also be described as a stream of particles, called photons, with higher and lower energies.
Light has been studied for centuries, from early experiments by Alhazen (to learn more about his research, see our Experimentation in Science module) to Einstein’s theory of general relativity. More recently, modern researchers have focused on harnessing the power of light, a field usually called “photonics” (from the Greek, photos, “light”). Photonics began in the 1960s with the development of the first lasers. By amplifying, or strengthening, the power of light waves, lasers create a type of light that is uniquely distinct and repeatable, creating a beam that can be controlled precisely. Lasers power much of our modern world – from the optical disk drives in our computers to the fiber-optic networks that form the backbone of the Internet.
Light plays an important role in many of our daily activities and has a significant impact on the quality of our lives. Fundamentally, as a form of energy, light is key to life on Earth, especially as the core requirement for photosynthesis. Light also enables us to see the world around us, as well as our place within it, and provides us a window on the universe. Light creates the colors of our world – from blue skies to brilliant sunsets – allowing us to recognize and categorize the natural world. Light also inspires human culture, like art and literature where shade and color help to evoke moods and atmospheres. By harnessing the power of light, scientists have made the world more connected (e.g., through optical fiber cables that form the global internet’s framework), more knowledgeable (via x-ray machines in healthcare, for example), and more earth-conscious (by using solar technologies instead of fossil fuels).
So the next time you flip a light switch, or play a disk in an optical drive, or bask in the Sun’s warmth, take a moment to reflect on the vital role light plays in our lives.
- International Year of Light and Light-Based Technologies website – http://www.light2015.org/Home.html
- Photonics and Our Daily Life (European Commission) – https://ec.europa.eu/digital-agenda/en/photonics-and-our-daily-life
- Virtual Exhibit (Light Beyond the Bulb) – http://lightexhibit.org/
- Virtual Laser Exhibit (SPIE) – http://spie.org/x39914.xml
Written by Eric Dillalogue
Eric Dillalogue holds a MS in Library and Information Science and a BA in English. He has worked in a variety of roles from service industry management, academic libraries, and grant administration. He has taught courses on information literacy, web research, and developmental reading. Eric joined the Visionlearning team as a project manager in 2014.