13.1. Fundamentals of Light http://www.ck12.org
13.1 Fundamentals of Light
- Describe electromagnetic radiation.
- State the speed of light in air.
- Use the speed of light to solve problems.
- Define luminous, illuminated, transparent, translucent, opaque and polarized.
- Understand the difference between color from pigment and color from light.
White light is composed of an infinite number of individual colors. Your eye blends the colors and your brain “sees”
white light. A prism, such as the one shown above and on Pink Floyd’s album cover, is able to resolve the light back
into individual colors.
Fundamentals of Light
Electromagnetic Radiation Spectrum
We only see objects that have light waves that travel from them to our eyes. Objects either generate light or reflect
it. Light is generated by incandescent and fluorescent lamps, light emitting diodes, flames, very hot objects, and even
some animals. Our major source of light is the sun. Light is a small fraction of the energy we callelectromagnetic
radiation.
Electromagnetic radiation is a form of energy that consists of oscillating electric and magnetic fields traveling at the
speed of light. Electromagnetic waves carry this energy from one place to another and are similar to waves in a rope.
Unlike the wave in a rope, however, electromagnetic waves do not require a medium to travel; the most prevalent
electromagnetic waves we experience travel through the vacuum of outer space from the sun.