Learning Event 2:
DESCRIBE THE BEHAVIOR OF LIGHT
1. Light energy travels in rays. These rays differ in color depending on
their wavelength but their speed remains constant as long as they travel
through a medium of constant density. The speed of the light decreases in
speed when it strikes a second medium of greater density and the light speed
increases when it strikes a second medium of lesser density (table 1-1).
When light strikes any second medium at any angle other than 90 degrees, the
light rays bend (refract) (fig 1-4).
Figure 1-4.
Light refraction
Table 1-1.
Speed of light
2. When light rays, which travel in
a straight line, encounter
any
substance, they are either reflected,
absorbed or transmitted or
any
combination thereof (fig 1-5).
Figure 1-5.
Reaction of light encountering a substance
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