The light spectrum, also known as the electromagnetic spectrum, encompasses a wide range of electromagnetic waves with varying wavelengths and frequencies. Here are the main features of the light spectrum:
Wavelength: The light spectrum consists of waves of different lengths, which are measured in meters or fractions of meters. It spans from very long wavelengths, such as radio waves, to very short wavelengths, such as gamma rays. Wavelengths determine the color of light, with longer wavelengths corresponding to colors like red and shorter wavelengths corresponding to colors like violet.
Frequency: Frequency refers to the number of complete wave cycles that pass a given point per second. It is measured in hertz (Hz). The frequency of light waves is inversely proportional to their wavelength, meaning that shorter wavelengths have higher frequencies and vice versa.
Range: The light spectrum encompasses a broad range of wavelengths, ranging from extremely long radio waves, through microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and finally to very short gamma rays. The full spectrum covers a range of approximately 10^24 to 10^-12 meters.
Visible light: Within the light spectrum, the portion that is visible to the human eye is known as visible light. It spans wavelengths from approximately 400 to 700 nanometers (nm). This range includes the colors of the rainbow: violet, indigo, blue, green, yellow, orange, and red.
Other regions: Apart from visible light, the light spectrum includes other regions that are not directly visible to humans. These regions include:
- Infrared: It lies just beyond the red end of the visible spectrum and is associated with heat radiation. Infrared waves have longer wavelengths than red light.
- Ultraviolet: It lies just beyond the violet end of the visible spectrum and has shorter wavelengths than violet light. Ultraviolet waves are responsible for effects like tanning and sunburn and can be classified into UVA, UVB, and UVC regions.
- X-rays: These have shorter wavelengths and higher frequencies than ultraviolet light. X-rays are used in medical imaging and other applications to visualize internal structures.
- Gamma rays: They have the shortest wavelengths and highest frequencies in the electromagnetic spectrum. Gamma rays are often associated with nuclear reactions and radioactive decay.
It's important to note that these features of the light spectrum are not separate entities but rather a continuous range of electromagnetic waves, each with its own unique characteristics.