One thing about the book is the kindness that author shows towards the students and teaches them step by step knowing that we may have a very low knowledge in subject. Another issue that makes me very upset is lack of any example and also how to measure and with what device in even a mental scenario. That doesn't exists and if I don't have even one practical question then I have more questions than answers. For practical , I have bought a plasma globe and tried to see if the value on the globe is correct by the equation but neither I know the volt/ meter of the center of the globe nor my voltmeter shows a constant volt on the surface. It reads 41 volt in AC then -2 volt in DC?! Taking in consideration the E value, permittivity constant is available on google of Pyrex glass but I am not sure if what I get is correct. How do we know if this formula is correct when we can't even calculate it!? We just have to have " faith" that others have done so , so accept it! That is more like religion not science.<br>Reminds me of a wise guy who was once asked by a king to count the number of stars and get gold if correct, wise guy said " it is equal to the number of the hair of my donkey! If you don't believe it please go count it for your self!".