Antisolar point anthelic point, such as the anthelion, Wegener arcs, Tricker arcs and the parhelic circle itself. 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
Overhead valve engine the first V-8 engine with OHV's to be produced on a wide scale. General Motors is the world's largest pushrod engine producer, producing I4, V6 and V8 pushrod engines. Most other companies use overhead cams. Nowadays, automotive use of side-valves has virtually disappeared, and valves are almost all "overhead". However, most are now driven more directly by the overhead camshaft system. Few pushrod-type engines remain in production outside of the United States market. This is in part a result of some countries passing laws to tax engines based on displacement, because displacement is somewhat related to the emissions and fuel