Nabla
Encyclopedia
Nabla may refer to one of the following:
- the nabla symbolNabla symbolright|thumb|256px|The [[harp]], the instrument after which the nabla symbol is namedNabla is the symbol \nabla . The name comes from the Greek word for a Hebrew harp, which had a similar shape. Related words also exist in Aramaic and Hebrew. The symbol was first used by William Rowan Hamilton in...
, which is used to denote the mathematical delDelIn vector calculus, del is a vector differential operator, usually represented by the nabla symbol \nabla . When applied to a function defined on a one-dimensional domain, it denotes its standard derivative as defined in calculus...
operator where tensorTensorTensors are geometric objects that describe linear relations between vectors, scalars, and other tensors. Elementary examples include the dot product, the cross product, and linear maps. Vectors and scalars themselves are also tensors. A tensor can be represented as a multi-dimensional array of...
is formal. - Nabla (instrument), a Hebrew stringed instrument after which that symbol was named, see harpHarpThe harp is a multi-stringed instrument which has the plane of its strings positioned perpendicularly to the soundboard. Organologically, it is in the general category of chordophones and has its own sub category . All harps have a neck, resonator and strings...
. - Nabla, tradename of a type of rail fastening systemRail fastening system-History and overview:The earliest wooden rails were fixed to wooden sleepers by pegs through holes in the rail, or by nails. By the 17th century cast iron rails had come into use, and also had holes in the rail itself to allow them to be fixed to a support...
(of roughly triangular shape).