2 ms·

They are talking about terahertz bands that aren't suitable for distance communication, the ranges are practically measured in centimeters.

• lutusp 14y ago
  > They are talking about terahertz bands that aren't suitable for distance communication, the ranges are practically measured in centimeters. If this argument had merit, light would be unsuitable for long-distance communication.
  • trotsky 14y ago
    Water vapor in these bands is a strong absorber limiting distance in earth's atmosphere to ~10 meters or less. Subtract a good deal for omnidirectional emissions and decent snr.
    • lutusp 14y ago
      That's very wavelength-specific, as this graph shows: http://upload.wikimedia.org/wikipedia/commons/thumb/d/db/Atmospheric_Microwave_Transmittance_at_Mauna_Kea_%28simulated%29.svg/350px-Atmospheric_Microwave_Transmittance_at_Mauna_Kea_%28simulated%29.svg.png http://upload.wikimedia.org/wikipedia/commons/thumb/d/db/Atm... Water and water vapor has the same effect on the visual part of the spectrum also, but this doesn't reduce people's enthusiasm for it as a potential communications medium. http://en.wikipedia.org/wiki/Terahertz_radiation http://en.wikipedia.org/wiki/Terahertz_radiation