Spectrum (1)
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The document discusses the origins and development of electronic media and the electromagnetic spectrum. Samuel Morse invented the telegraph in 1842. In the 1860s, James Clerk Maxwell theorized electromagnetism. In the 1880s, Heinrich Hertz proved the existence of the electromagnetic spectrum through experiments with sparks. The spectrum is now under increasing strain from technologies like cell phones, WiFi, satellites, and other wireless devices.
Spectrum (1)
- 1. Origins of electronic media • 1842- Samuel Morse invents the telegraph. • 1860s: James Clerk Maxwell theorizes the existence of electromagnetism • 1880s: Heinrich Hertz proves the existence of the spectrum with spark-gap experiment.
- 3. The New Millennium • Spectrum is under increasing stress vis cellphones, microwave, satellite and other emerging media • E.g., today there are over 219 million U.S. wireless phone subscribers • There are more wireless phones than landlines in the United States today • POBs (plain old b-cast services) are also making greater demands on spectrum
- 4. Radio & the electromagnetic spectrum