Antisolar point Antisolar point The antisolar point is the abstract point on the celestial sphere directly opposite of the Sun from an observer's perspective. This means that the antisolar point lies above the horizon when the Sun is below it, and vice versa. On a sunny day, the antisolar point can be easily found; it is located within the shadow of the observer's head. Like the zenith and nadir, the antisolar point is not fixed in three-dimensional space, but is defined relative to the observer. Each observer has their own antisolar point, which moves along with them as they change position. The
Preliminary Discourse to the Encyclopedia of Diderot reflection or reason, which is the basis of Philosophy; and what d'Alembert refers to as "imagination," (50) or imitation of Nature, which produces Fine Arts. From these divisions spring smaller subdivisions such as physics, poetry, music and many others. d'Alembert was also greatly influenced by the Cartesian principle of simplicity. In this first part of the book, he describes how the reduction of the principles of a certain science gives them scope and makes them more "fertile" (22). Only by reducing principles can they be understood and related to each other. Ultimately, from a high "vantage point" (47) the philosopher