Light has color, which is a critical property to understand.
To comprehend color, it's beneficial to think of light as a wave.
Waves exhibit repetitive or periodic motion, exemplified by a cork bobbing in the ocean.
The cork's motion follows a consistent path: up and down repeatedly.
The time for the cork to complete one full cycle is the wave's period (e.g., 2 seconds).
Frequency is the measure of how often waves pass in one second.
In this example:
Period = 2 seconds → Frequency = 0.5 waves/second.
Light also has frequency, which relates directly to its color.
Color is essentially a measure of the frequency of light waves.
Our eyes detect these frequencies, but cannot see light’s periodic motion due to its rapid frequency (e.g., over 400 million times/second).
Visible spectrum:
Lowest frequency: Red
Highest frequency: Purple
Intermediate frequencies create a continuous band of color.
An object's color is determined by the light it reflects:
A yellow pencil reflects yellow light and absorbs other colors (blue, purple, red).
Blue objects reflect blue light, red objects reflect red, etc.
White objects reflect all colors; black objects absorb all frequencies.
Absorption of certain light frequencies by objects can generate heat (why dark clothes feel hot in sunlight).