Electrical resistivity and conductivity results in the important concept of "quasineutrality", which says the density of negative charges is approximately equal to the density of positive charges over large volumes of the plasma ("n" = <Z>"n"), but on the scale of the Debye length there can be charge imbalance. In the special case that "double layers" are formed, the charge separation can extend some tens of Debye lengths. The magnitude of the potentials and electric fields must be determined by means other than simply finding the net charge density. A common example is to assume that the electrons satisfy the Boltzmann relation: Differentiating this
Negative and positive atheism atheism as a way of life in his 1972 book, "Positive Atheism". Similarly, the Atheist Community of Austin (ACA) uses the term "positive atheism" in the sense of putting a positive face to atheism and dispelling the false and negative image of atheism portrayed by religious people, especially in places of worship. "Positive Atheism Magazine" "sees atheism as being a positive, healthy outlook -- much healthier than any theistic approach to life." Agnostics are not always merely implicit atheists. For instance, Philip Pullman, the English author of the "His Dark Materials" fantasy trilogy, which has atheism as a major theme,