# What is the Difference Between the Energy Current (Waves) and the Electric Current?

In Waves and Optics, my class has just been introduced to energy current. It is the flow of energy through a wire, yes? ... How exactly is this different from electricity (Electricity and Magnetism)? Thank you.

• "Energy current" is not a term that is in general use, so it probably does not have a standard meaning. Your instructor must be using the term in a special way that makes sense to him. Better not to introduce non-standard terminology, but it's ok if it's well defined and used consistently throughout a text. We might be able to offer more help if you tell us exactly how it is defined in your class. Feb 6 at 22:02
• Thank you! Here,energy current(either to the left or right) is defined as the energy density(either to the left or to the right) multiplied by the wave speed. The professor also writes the the energy current in the positive direction is equal to 0.5*T*A^2*k^2*v, where T is the tension force, A is the amplitude, k is the spatial frequency, and v is the wave speed - in Fourier representation! Physically it is defined as the energy flowing through a wire - so I am confused on how it is different from the electric current? Thanks. Feb 6 at 22:25
• Also, of note, the energy density is described as the thing you integrate along the length of the wire (x) to yield the Energy. Feb 6 at 22:26