Spectrum of Electromagnetic Radiation

The electromagnetic radiation spectrum is the range of all types of electromagnetic radiation that vary from each other by wavelength, frequency, and energy.

Physics

Properties

The electromagnetic radiation contains two components: electric and magnetic. The electric field is characterized by the electric field intensity vector 𝐸⃗. The magnetic component is characterized by the magnetic induction vector 𝐵⃗. making

All EM waves travel at the speed of light (c = ~3 × 10⁸ m/s) in a vacuum, but they differ in energy and how they interact with matter.

c = λf

λ = Wavelength (meters)

f = Frequency (Hertz, 1/sec)

Spectrum

The electromagnetic spectrum is the entire range of radiation, spanning from long-wavelength/low-frequency radio waves to short-wavelength/high-frequency gamma rays. All EM radiation travels at the speed of light, with7 major types: Radio, Microwave, Infrared, Visible, Ultraviolet, X-ray, and Gamma Ray. Ionizing radiation is high-energy electromagnetic waves (Gamma Rays, X-rays, and strong UV) that can eject electrons from atoms. Lower-energy waves, such as radio or Microwave, are non-ionizing.

Radio Waves

Wavelength: 1 mm to 100 km

Source: Electromagnetic oscillator

Uses:

• Radio and television signal transmission
• Mobile phone communication
• Radio communication and radar

Medical use:

• Plastic surgery (radiocoagulation – stopping bleeding or cutting tissue)
• Magnetic resonance imaging (MRI)

Microwaves

Wavelength: 1mm (millimeter) to 1m(meter).

Source: Magnetron

Uses:

• Microwave ovens
• Drying wood and books
• Wireless communication (Wi-Fi)

Medical use:

• Plastic surgery
• Rehabilitation

Infrared Radiation

Wavelength: 0.1 mm – 780 nm

Source: Hot objects (e.g., infrared heaters); almost all objects emit it

Properties:

• Follows the same laws as visible light
• Penetrates better through cloudy environments

Uses:

• Electronics (remote controls, mobile phones)

Medical use:

• Uses thermal energy
• Improves lymphatic drainage
• Enhances tissue nutrition

Visible Light

Wavelength: 750 nm – 380 nm

Sources:

• Natural (e.g., the Sun, fire)
• Artificial (e.g., lamps, lasers, light bulbs)

Properties:

• Has dual nature (wave and particle)
• Studied in optics

Uses:

• Main source of information for humans (vision)
• Essential for plants (photosynthesis)
• Used in devices (screens, DVD players, phones, optical instruments like microscopes and telescopes)

Medical use:

• Phototherapy (heliotherapy, climatotherapy)
• Treatment of depression

Effects on the human body:

• Blue/violet light → photochemical effects (can cause skin conditions like photodermatosis)
• Red light → thermal effect (can cause overheating)

Ultraviolet Radiation (UV)

Wavelength: 400 nm – 100 nm

Source: High-temperature bodies (Sun, stars), electric arcs (welding), mercury lamps

Properties:

• Ionizing
• Affects photographic plates
• Can be converted to visible light (e.g., banknote security features)
• Causes luminescence
• Absorbed by ordinary glass (but not by quartz glass)

Medical use:

• Disinfection (kills microorganisms)

Effects on the human body:

• Small doses → tanning, vitamin D production
• High doses → skin cancer (DNA damage)
• Can cause conjunctivitis

Protection:

• The ozone layer absorbs much of UV radiation and protects life on Earth

X-rays

Wavelength: 10 nm – 1 pm

Source: X-ray tubes

Properties:

• Affect photographic plates
• Ionize air and substances

Uses:

• Material inspection (defectoscopy)
• X-ray astronomy
• Crystal structure analysis

Medical use:

• Mainly diagnostics (imaging)
• High-energy X-rays used to treat tumors

Effects on the human body:

• Harmful → requires strict safety measures

Protection:

• Shielding (e.g., lead)
• Minimize exposure time

Gamma Radiation

Wavelength: < 1 pm

Source: (commonly from nuclear processes)

Properties:

• Strong ionizing effects
• Releases charged particles (photoelectric effect)

Uses:

• Detecting defects in materials
• Food preservation (meat, vegetables)

Medical use:

• Gamma knife (focused beams destroy tumor cells)
• Sterilization (kills bacteria)

Effects on the human body:

• Causes genetic mutations
• Radiation sickness
• Can lead to cancer

source

wikiskripta-Elektromagnetické spektrum

wikipedia- Electromagnetic spectrum

canada.ca- Understanding Radiation