ELF
Science & Engineering abbreviation · Physics
| Stands for | Extremely low frequency |
|---|---|
| Categories | Science & Engineering |
ELF stands for Extremely low frequency, a physics abbreviation.
Radio band from 3 to 30 hertz in the ITU scheme, although health studies often use ELF for fields up to 300 hertz, including those from 50 and 60 Hz power lines. ELF waves penetrate seawater and the ground, so navies used them to send short messages to submerged submarines.
Example: The Navy's ELF transmitters in Wisconsin and Michigan broadcast at 76 Hz until they closed in 2004.
Usage notes
ELF antennas must be enormous, stretching for tens of kilometers, and they transmit only a few characters per minute. Natural ELF signals include Schumann resonances, around 7.8 Hz, created by lightning in the cavity between Earth's surface and the ionosphere.
Related abbreviations
More physics abbreviations
- CCD – Charge-coupled device
- CERN – European Organization for Nuclear Research
- CMP – Condensed matter physics
- CMS – Compact Muon Solenoid
- COM – Center of mass
- CP – Charge-parity (symmetry)
- EM – Electromagnetic
- EMF – Electromagnetic field
- EMP – Electromagnetic pulse
- EMR – Electromagnetic radiation
- EPR – Einstein-Podolsky-Rosen (paradox)
- EUV – Extreme ultraviolet