How Light Works

1. What Part of the EM Spectrum is Visible Light?

Visible light is only a small part of the EM Spectrum. It is between 400 and 700 nanometers in wavelength.



2.Is light considered a wave or a particle?

It is considered both a wave and a particle.

3. In order for us to see an object, it must be illuminated or luminous.

a. What does it mean to be luminous?

b.What does it mean to be illuminous?

Something which emits light is addressed as luminous. The light referred is generally self-generated. For example: sun is luminous hot body.

4. How fast is light?

Light travels at a speed of 299,792 kilometers per second; 186,287 miles per second.

5. What does light have to do with colors and how we see things?

We see light that bounces off of things around us. When the light enters our eyes, special cells tell our brains about the light.
The visible wavelength colors can be seen when you look at a rainbow. Raindrops acting as natural prisms produce the colors.

6. What are pigments and how are they realated to light?

Pigments are colorful compounds.Because they interact with light to absorb only certain wavelengths, pigments are useful to plants and other autotrophs

7. Light will travel in a straight line until it hits something. Depending on the characteristics of the object, light will be reflected, transmitted, or refracted.

A. What does it mean for light to be reflected?

Objects can be seen by the light they emit, or, more often, by the light they reflect.

B. What does it mean for light to be transmitted?


C. What does it mean for light to be refracted?

When light travels from one medium to another, the speed changes, as does the wavelength.

8.An object can be transparent, translucent, or opaque.

A. What happens when light hits a transparent object? What is an example of a transparent object?

B. What happens when light hits a translucent object? What is an example of a translucent object?

C. What happens when light hits an opaque object? What is an example of an opaque item?