lühisagedusi

Lühisagedusi, often translated as "short frequencies" or "low frequencies" in English depending on the context, refers to a range of electromagnetic or sound wave frequencies that are considered low. In radio communication, short frequencies typically fall within the Very Low Frequency (VLF), Low Frequency (LF), and Medium Frequency (MF) bands. These frequencies have longer wavelengths, which allow them to travel longer distances and penetrate obstacles like buildings and water more effectively than higher frequencies.

VLF waves, for example, are used for underwater communication with submarines due to their ability to penetrate saltwater. LF and MF bands have historically been used for AM radio broadcasting and some navigation systems. The propagation characteristics of lühisagedusi are distinct, often exhibiting ground wave propagation, where the waves follow the curvature of the Earth, and skywave propagation, where they are reflected by the ionosphere, enabling long-distance communication, especially at night.

In the context of sound, lühisagedusi refers to low-pitched sounds. The human ear can typically perceive frequencies from around 20 Hz to 20,000 Hz. Sounds below this range are considered infrasound, while sounds above are ultrasound. Low-frequency sounds can be felt as much as heard and can travel great distances with less attenuation. They are generated by various natural phenomena like earthquakes and volcanic eruptions, as well as by man-made sources such as large machinery and musical instruments. Understanding lühisagedusi is crucial in fields ranging from telecommunications and broadcasting to acoustics and geophysics.