The neper (unit symbol Np) is a logarithmic unit for ratios of measurements of physical field and power quantities, such as gain and loss of electronic signals. The unit's name is derived from the name of John Napier, the inventor of logarithms. As is the case for the decibel and bel, the neper is a unit of the International System of Quantities (ISQ), but not part of the International System of Units (SI), but it is accepted for use alongside the SI.
In ancient Egyptian religion, Neper (alts. Nepra or Nepri) was a god of grain. His female counterpart was Nepit, the goddess of grain.
Neper is an old lunar impact crater located near the eastern limb of the Moon. Due to its location the crater must be viewed during a suitable libration, and is very foreshortened. The crater lies on the south edge of Mare Marginis, to the east of the crater Jansky. To the northwest across the Mare Marginis is the crater Goddard.
The crater inner walls have worn terraces, with low rim edges at the northern and southern extremes. The crater floor is dark and flat, with a central peak and several crater impacts near the west rim. The most notable of these is a small crater near the north-northwestern edge.
It is named after the Scottish mathematician, physicist, astronomer and astrologer John Napier.
Neper is a logarithmic unit of ratio.
Neper may also refer to:
- John Napier, a Scottish mathematician
- Neper (crater), a lunar impact crater
- Neper (mythology), an Egyptian deity
n. A unit of attenuation used in transmission line theory; equivalent to 8.686 dB.