Correct! - and an alternating electric current is represented as a complex number (then it's conventional to use the symbol 'j' for sqrt(-1) to avoid confusion with 'i', the symbol for electric current!). Since as you say electric current is a scalar not a vector, then a complex number has to be a scalar, not a vector!
Cheers -- Ian On Thu, Oct 14, 2010 at 3:47 PM, Ganesh Natrajan <natra...@embl.fr> wrote: > The definition of a vector as being something that has 'magnitude' and > 'direction' is actually incorrect. If that were to be the case, a > quantity like electric current would be a vector and not a scalar. > Electric current is a scalar. > > A vector is something that transforms like the coordinate system, while > a scalar does not. In other words, if you were to transform the > coordinate system by a certain operator, a vector quantity in the old > coordinate system can be transformed into the new one by using exactly > the same operator. This is the correct definition of a vector. > > G. > > > > On Thu, 14 Oct 2010 10:22:59 -0400, Ed Pozharski > <epozh...@umaryland.edu> wrote: >> The definition game is on! :) >> >> Vectors are supposed to have direction and amplitude, unlike scalars. >> Curiously, one can take a position that real numbers are vectors too, if >> you consider negative and positive numbers having opposite directions >> (and thus subtraction is simply a case of addition of a negative >> number). And of course, both scalars and vectors are simply tensors, of >> zeroth and first order :) >> >> Guess my point is that definitions are a matter of choice in math and if >> vector is defined as an array which must obey addition and scaling rules >> (but there is no fixed multiplication rule - regular 3D vectors have >> more than one possible product), then complex numbers are vectors. In a >> narrow sense of a real space vectors (the arrow thingy) they are not. >> Thus, complex number is a Vector, but not the vector (futile attempt at >> using articles by someone organically suffering from article dyslexia). >> >> Cheers, >> >> Ed. >> >> >> O > -- > ********************************************** > Blow, blow, thou winter wind > Thou art not so unkind > As man's ingratitude; > Thy tooth is not so keen, > Because thou art not seen, > Although thy breath be rude. > > -William Shakespeare > ********************************************** >
