A laser pointer used in a lecture hall emits light at 650 nm. Using Figure 6.4, predict the color associated with this wavelength.

Key Concepts

Electromagnetic Spectrum

The electromagnetic spectrum encompasses all types of electromagnetic radiation, including visible light, which ranges from approximately 400 nm (violet) to 700 nm (red). Each wavelength corresponds to a specific color perceived by the human eye. Understanding where 650 nm falls within this spectrum is essential for predicting the color emitted by the laser pointer.

Wavelength and Color Perception

Wavelength is a key factor in determining the color of light. In the visible spectrum, shorter wavelengths correspond to colors like violet and blue, while longer wavelengths correspond to red. At 650 nm, the light emitted by the laser pointer is in the red region of the spectrum, which is crucial for accurately identifying the color associated with this wavelength.

Color Mixing and Perception

Color perception is influenced by how different wavelengths of light mix and how they are interpreted by the human eye. The primary colors of light (red, green, and blue) combine in various ways to produce other colors. In the case of a laser pointer emitting light at 650 nm, the direct perception of red light is straightforward, as it does not involve mixing with other colors.