 
 <prompt> Wetin Coulomb's law dey concern itself with? Given di previous question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: ```QED vacuum get interestin and complex properties. For QED vacuum, di electric and magnetic fields get zero average values, but their variances no dey zero. As e be so, QED vacuum dey contain vacuum fluctuations (virtual particles wey dey jump in and out of existence), and a finite energy wey dem call vacuum energy. Vacuum fluctuations na important and common part of quantum field theory. Some effects wey don dey verify for experiment wey dey come from vacuum fluctuations include spontaneous emission and the Lamb shift. Coulomb's law and di electric potential for vacuum wey dey near an electric charge dey change.``` 