Electromagnetic Radiation

• Electromagnetic Radiation

  The interplay of electric and magnetic fields.
• Electromagnetic waves = Transverse waves
• Electromagnetic waves were predicted by: James Clerk Maxwell
• Electromagnetic waves were proved by: Heinrich Hertz
• Electromagnetic Spectrum

  A continuous range of electromagnetic waves arranged by frequency or wavelength.
• Radio waves were discovered by: Heinrich Hertz in 1887
• RADAR - Radio Detection and Ranging
• Wi-Fi - Wireless Fidelity.
• GPS - Global Positioning System.
• RFID - Radio Frequency Identification.
• MRI - Magnetic Resonance Imaging.
• Micro waves were discovered by: James Clerk Maxwell in 1864
• Uses of micro waves:

  • Communication (2.40 GHz)
  • Radio Broadcasting
  • Long-distance calls
  • Cable TV
  • Microwave ovens
• Infrared radiation means "below red"
• Infrared radiation are the only waves that can be felt through heat
• Infrared radiation was discovered by: Sir William Herschel in 1800
• Uses of Infrared Radiation:

  • Remote controls
  • Alarm systems
  • night vision
  • cooking
  • medical infrared imaging
• Visible light is the only visible spectrum to the naked eye
• Visible light was discovered by: Isaac Newton
• What does ROYGBIV stand for?

  Red Orange Yellow Green Blue Indigo Violet
• VLC - Video light communication
• LASER - Light Amplification by Stimulated Emission of Radiation.
• LCD - liquid-crystal display
• Ultraviolet Radiation was discovered by: Johann Wilhelm Ritter
• Three types of UV: UVA, UVB, and UVC
• UVA: Penetrates the dermis.
• UVB: Filtered by ozone, penetrates the epidermis.
• UVC: Completely absorbed by the atmosphere.
• Uses of Ultraviolet Radiation:

  • Black lights.
  • Detecting forged banknotes.
  • Forensic investigations.
  • Water purification.
  • UVA treatment for skin conditions.
• X-Radiation (X-Rays) was discovered by: Wilhelm Conrad Roentgen.
• X: Refers to unknown origin and nature.
• Soft X-Rays: Lower energy (medical)
• Hard X-Rays: More penetrating (industrial)
• Uses of X-Radiation:

  • Detecting skeletal abnormalities.
  • Dental imaging.
  • CT Scans (Computed Tomography). - CT Scan
  • Airport Security
• Gamma Radiation was discovered by: Paul Villard.
• Uses of Gamma Rays:

  • Detecting cracks in metals.
  • Sterilizing equipment.
  • Killing bacteria in food processing.
  • Breeding new seeds.
  • Chemotherapy
• Radiotherapy: killing cancer cells (external)
• Brachytherapy: using radioactive implants (internal)
• ● High wavelength = Low frequency.

  ● Low wavelength = High frequency.

  ● High frequency = High radiation.
• Ionizing radiation: Has enough energy to ionize