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