Microwaves and Radio Waves
See also: Radio windowThe pure rotation spectrum of water vapor extends into the microwave region.
Liquid water has a broad absorption spectrum in the microwave region, which has been explained in terms of changes in the hydrogen bond network giving rise to a broad, featureless, microwave spectrum. The absorption (equivalent to dielectric loss) is used in microwave ovens to heat food that contains water molecules. A frequency of 2.45 GHz, wavelength 122 mm, is commonly used.
Radiocommunication at GHz frequencies is very difficult in fresh waters and even more so in salt waters.
Read more about this topic: Electromagnetic Absorption By Water
Famous quotes containing the words radio and/or waves:
“The radio ... goes on early in the morning and is listened to at all hours of the day, until nine, ten and often eleven o’clock in the evening. This is certainly a sign that the grown-ups have infinite patience, but it also means that the power of absorption of their brains is pretty limited, with exceptions, of course—I don’t want to hurt anyone’s feelings. One or two news bulletins would be ample per day! But the old geese, well—I’ve said my piece!”
—Anne Frank (1929–1945)
“With these I would be.
And with water: the waves coming forward, without cessation,
The waves, altered by sand-bars, beds of kelp, miscellaneous
driftwood,
Topped by cross-winds, tugged at by sinuous undercurrents
The tide rustling in, sliding between the ridges of stone,
The tongues of water, creeping in, quietly.”
—Theodore Roethke (1908–1963)