Electromagnetic Spectrum Electromagnetic waves Produced by the movement
Electromagnetic Spectrum
Electromagnetic waves • Produced by the movement of electrically charged particles • Can travel in a “vacuum” (they do NOT need a medium) • Travel at the speed of light • Also known as EM waves
Electromagnetic radiation waves • Waves are three dimensional • Waves vibrate in all planes around a center line. wavelength
Remember radio waves are long…and gamma rays are small Radio-TV -Microwave- Infrared - VISIBLE -Ultraviolet -X-rays - Gamma- Cosmic
Radio (Longest electromagnetic waves) • Emitted by – Astronomical Objects – Radio Station Transmitters • Detected by – Ground based radio telescopes – *If you turn on a radio, it will convert the radio wave energy into sound energy.
Radio waves • Wavelength: 100 km – 100 m • Uses: – TV broadcasting – AM and FM broadcast radio – Avalanche beacons – Heart rate monitors – Cell phone communication
Microwave • Emitted by: – Gas clouds collapsing into stars – Microwave Ovens – Radar Stations – Cell Phones • Detected by – – Microwave Telescopes Food (heated) Cell phones Radar (systems)
Microwaves • Wavelengths from 1 mm- 1 m • Uses: – Microwave ovens – Bluetooth headsets – Broadband Wireless Internet – Radar – GPS
Infrared (Heat or Thermal) Are you a source of infrared? YES you are! • Emitted by – Sun and stars (Near) – TV Remote Controls – Food Warming Lights (Thermal) – *Everything at room temperature or above, =HEAT • Detected by – Infrared Cameras – TVs, VCRs, – Your skin
Infrared Radiation • Wavelengths: 750 nm-1 mm • Uses: – Night vision goggles – Remote controls – Heat-seeking missiles
Visible Each color is a different size wave. Red the longest & violet the shortest • Emitted by – The sun and other astronomical objects – Laser pointers – Light bulbs • Detected by – Cameras (film or digital) – Human eyes – Plants (red light) – Telescopes
Visible light • Only type of EM wave able to be detected by the human eye • Violet is the highest frequency light • Red light is the lowest frequency light
Visible light • Wavelength: 390 nm – 750 nm • Uses: – Enables us to see things – Photosynthesis in plants
Ultraviolet Sunburn / black light • Emitted by – – Tanning booths (A) The sun (A) Black light bulbs (B) UV lamps • Detected by – Space based UV detectors – UV Cameras – Flying insects (flies)
Ultraviolet • Wavelength: 10 nm – 400 nm • Uses: – Black lights – Sterilizing medical equipment – Water disinfection – Security images on money
• Emitted by – – – X-ray Astronomical objects X-ray machines CAT scan machines Older televisions Radioactive minerals Airport luggage scanners • Detected by – Space based X-ray detectors – X-ray film – CCD detectors
X-rays • Wavelength: 0. 01 nm – 10 nm – High energy • Uses: – Medical imaging – Airport security – Inspecting industrial welds
Gamma Ray (Short electromagnetic waves but more energetic) • Emitted by – Radioactive materials – Exploding nuclear weapons – Gamma-ray bursts – Solar flares • Detected by • --Geiger counters – Gamma detectors and astronomical satellites – Medical imaging detectors
Gamma Rays • Smallest wavelengths, highest energy EM waves • Wavelengths: less than 0. 01 nm • Uses – Food irradiation – Cancer treatment – Treating wood flooring
• A great question! • Radio waves= (Buildings to human size); • Microwaves (Humans-beetles); • Infrared waves (Eye of a needle); • Visible waves (microscopic size)! WOW! All the rest are the size of molecules, atomic nuclei and smaller. . See the next slide for more.
Relative Size
- Slides: 24