Light has different colors because each color corresponds to a different wavelength of visible light.
Essentially, what we perceive as different colors is the result of light waves with varying lengths entering our eyes. The visible light spectrum is a small portion of the electromagnetic spectrum, ranging from about 380 nanometers (nm) to 700 nm.
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Wavelength and Color: The wavelength of a light wave determines its color.
- Shorter Wavelengths: Colors like violet and blue have shorter wavelengths (around 380-450 nm).
- Longer Wavelengths: Colors like red and orange have longer wavelengths (around 620-700 nm).
- Intermediate Wavelengths: Colors like green and yellow fall in between.
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Prism Example: When white light passes through a prism, it separates into its constituent colors because each wavelength bends at a slightly different angle. This is what creates the rainbow effect.
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Human Perception: Our eyes contain specialized cells called cone cells that are sensitive to different wavelengths of light. These cells send signals to our brain, which interprets them as different colors. We have three types of cones, each most sensitive to red, green, or blue light. The combination of signals from these cones allows us to perceive a wide range of colors.
In summary, the color of light is determined by its wavelength; shorter wavelengths appear violet/blue, while longer wavelengths appear red/orange. Our eyes and brain work together to interpret these different wavelengths as the colors we see.
