Visible light differs from other types of electromagnetic radiation mainly in wavelength, frequency, energy, and human perception:
- Wavelength and Frequency
- Visible light has wavelengths of about 380–750 nanometers.
- It has frequencies between roughly 4 × 10¹⁴ Hz and 7.9 × 10¹⁴ Hz.
- Other types of electromagnetic radiation lie outside this range — for example, radio waves have much longer wavelengths, and gamma rays have much shorter ones.
- Energy of Photons
- Visible light photons have moderate energy compared to the spectrum — more energetic than infrared photons but less energetic than ultraviolet, X-rays, or gamma rays.
- Interaction with Matter
- Visible light is absorbed, reflected, or transmitted by materials in ways that often produce color.
- Other radiations may pass through objects without visible effects (radio waves), or cause chemical/biological changes (UV can damage DNA, microwaves heat water molecules).
- Human Perception
- Unique feature: Visible light is the only part of the electromagnetic spectrum our eyes can detect directly.
- Other types of radiation require special detectors (e.g., radio antennas, infrared cameras, X-ray film).