What is light? Light could be a number of different things, depending on the circumstances. It could be the glow from a light bulb in your bedroom or the warm shining rays that beat down from the sun. Light can be natural or manmade, but no matter how it is created, we utilize light every single day. Throughout the past century, there have been a number of scientific developments revolving around light.
The study of optics has allowed us to expand our knowledge on light waves and their interactions with all kinds of matter. Light is truly a wonder to behold, but there is so much to understand about this amazing concept. Fans of science will love learning how light works and the many uses that we have for this incredible type of energy. The next time you turn a light fixture in your home on, you'll have a new found appreciation for how the light radiating from it works.
The Science of Vision and Light
To put it simply, light is a type of radiant energy that we are able to visually perceive with our eyes. In other words, light is power that we can see! Visible light is a small part of a large part of what is called the Electromagnetic Spectrum, which contains all of the energy types that travel through space in a wave-like manor. Every day, light waves reflect off of objects and into our eyes, which allows us to see the objects. Human beings by far have the best visual system structure - even better than a bird, who has to see small objects from high above!
- The Science of Vision
- Rods and Cones
- Introduction to the Science Behind Vision
- Neuroscience for Kids: The Eye
The Science of Color and Light
To better explain how our eyes see color, imagine a green apple. Why does the apple appear green? Light shines onto the apple, causing the apple to absorb every color in the spectrum besides the color green. The color that the apple does not absorb is reflected back to our eyes, causing us to see green. Light is just a minor fraction of the entire Electromagnetic Spectrum. Within that small area lie all of the colors that we can see, called the visible spectrum.
All of the colors have different wave lengths that make them the colors that they appear. For example, red color waves are very long in length, while blue color waves are very short. Colors are also associated with temperature, or the way that the colors are perceived. Jumping back to our previous example, red is perceived as a warm color due to the psychological impact the color red has on our brains. Typically, warm objects are red, like a heating stovetop or a red flame.
Light plays a major role in how our eyes perceive color. The source of the light determines how our eyes see the color. For instance, if we are viewing a red shirt outside in the sunlight and then take it inside to look at it under a lamp, it may appear a darker shade due to the change in the Color Rendering Index, or how light makes colors appear.
- Biology for Kids - Sight and the Eyeball
- Light & Color
- Facts About Light and Color
- The Electromagnetic Spectrum
Lighting Metrics: Quantity, Quality, Efficiency
Lighting metrics are used to describe, understand, and predict how a source of light energy will operate. There are three components that make up lighting metrics, which include quantity of light, quality of light, and efficiency of light. Quantity of light has to deal with the levels of light that a source puts out, or the amount of light that leaves an object. This quantity is measured in lumens.
Quality of light refers to the brightness and color of the light that is emitted from an object, such as a ceiling fan with a light. Depending on the brightness of an object, glare may be produced. There are two types of glare, direct and reflected. Direct glare comes directly from a light source and hinders visibility. Reflected glare occurs when a light source reflects back off of an object and causes a glare.
The final lighting metric is lighting efficiency, or how much light actually leaves a source. Light efficiency is measured in watts, which you may have noticed on the packaging of your home's light bulbs. A light's efficiency is determined by how well it transforms electrical energy into light and by how well that light is transmitted from the object electricity is being pumped into.
Light Fixtures That Manipulate Light as a Design Feature
Lighting designers today, like Lithonia, are designing more than just your average light fixture; they are constructing works of art. Designers are using hand crafted metals, like iron, to shape light fixtures, such as pendants and chandeliers, into designs that not only look stunning with the lights off, but when you turn the lights on, make you feel as if you have been transported to an entirely different location.
Fun Light Facts and Websites
- Fun Facts on Light Energy
- Light and Other Physical Processes
- Science, Optics, and You- Light & Color