### energy | radiation | light:

Illuminance
* are luminosity.
  - measured in footcandles, which are workplane lumens per square foot
* is the amount of visible light per unit area falling on a surface
  - density of the luminous flux on a surface
  - scientific name for the measurement of incident light
  - term quantifying the illumination of, or incident light falling on a surface
* measure of photometric flux per unit area, or visible flux density

### energy | radiation | light:

Incandescent light
* Most incandescent light creates energy
  - emits more heat energy
* are the least expensive to purchase and provide good light
  - typically yellow or orange in tone while flourescents are more green
* can be slide projectors or overheads
  - make lichens look yellow
* emits energy
* heat a metal filament that radiates light inside a glass bulb.
* is also more compatible with computer monitors than fluorescent light
  - less damaging
* is produced by heating a filament
  - tungsten filament to a high temperature
  - too warm and regular fluorescent light is too cool
* produce all wavelengths of light and are closest to natural sunlight.
* produce mostly red and some infrared light, but very little blue light
  - red, and some infrared light, but are very low in blues
* provide a general lighting solution for work areas and living spaces
  - an amber glow that creates a relaxed setting

Incident light
* Most incident light has effects
  - positive effects
* fluoresces a transparent reference material, and the fluorescent light is polarized.
* is light coming from the source before it strikes a subject or surface
  - falling on a surface, as opposed to reflected by it
  - the light falling on a subject
* occurs when the light source is to one side of the magnifier.

Indoor light
* can fritz out when they get wet, and Outdoor lights get too hot when used inside.
* is usually quite different from outside sunlight.

### energy | radiation | light:

Infrared light
* are waves with frequencies that are a little lower than human vision.
* can pass through the body
  - penetrate the smog to see Titan's surface
  - reveal the underdrawing that lies below the paint surface
* consists of very long waves.
* different wave length than normal lenses have their back focus adjusted to.
* enables astronomers to peer past interstellar dust.
* is considered safe to humans
  - emitted by an object because of what is happening at the atomic level
  - emitted, reflected by the ground, and received by the sensor
  - given off by less energetic processes in space in general
* is invisible and can be very dangerous
  - but is easily felt
  - to the eye
* is invisible to the human eye, but some types are perceived as heat
  - less affected by dust
  - much redder than the red light visible to the human eye
* is pulsed through the fiber net
  - throughout the fiber
  - radiated from any object with a temperature
  - reflected off the border between the sclera and the iris
  - transmitted to sensors placed on the sides of the forehead
* picks up motion and converts it to music, which the audience can hear.
* shines upward from the surface of the earth, brighter if the ground is warmer.
* small part of the light spectrum.
* tends to record the heat coming off of an object or the environment.

Insufficient light
* can cause leaf drop.
* is probably the most common reason for failure of African violets to flower
  - the most frequent cause of failure to flower

Intensified light
* can cause fires, burns and be harmful to the eyes.
* is reflected, refracted, scattered, resisted and absorbed.