====== Divergence ======


<tabbox Intuitive> 

<blockquote>Divergence (div) is “flux density”—the amount of [[basic_tools:vector_calculus:flux|flux]] entering or leaving a point. Think of it as the rate of flux expansion (positive divergence) or flux contraction (negative divergence). If you measure flux in bananas (and c’mon, who doesn’t?), a positive divergence means your location is a source of bananas. You’ve hit the Donkey Kong jackpot.

<cite>[[https://betterexplained.com/articles/divergence/|Vector Calculus: Understanding Divergence]] by Kalid Azad</cite></blockquote>
  
<tabbox Concrete> 

  * [[https://betterexplained.com/articles/divergence/|Vector Calculus: Understanding Divergence]] by Kalid Azad
  * Another great discussion of the divergence in vector calculus can be found in Section 3 of Vol. 2 of Feynman's Lectures on Physics, which is available [[http://www.feynmanlectures.caltech.edu/II_03.html|here]]
 
<tabbox Abstract> 

<note tip>
The motto in this section is: //the higher the level of abstraction, the better//.
</note>

  
<tabbox Why is it interesting?> 

The divergence is a crucial tool, for example, in [[models:classical_electrodynamics|electrodynamics]]. This can be seen immediately because the fundamental equations of electrodynamics (called [[equations:maxwell_equations|Maxwell equations]]) contain the divergence of the electric and magnetic fields.


</tabbox>