Solid angle a solid angle in steradians is the following ratio: where A is the spherical surface area and r is the radius of the considered sphere. Solid angles are often used in physics, in particular astrophysics. The solid angle of an object that is very far away is roughly proportional to the ratio of area to squared distance. Here "area" means the area of the object when projected along the viewing direction. The solid angle of a sphere measured from any point in its interior is 4 sr, and the solid angle subtended at the center of a cube by one
Solid surface Solid surface Solid surface is a man-made material usually composed of a combination of alumina trihydrate (ATH), acrylic, epoxy or polyester resins and pigments. It is most frequently used for seamless countertop installations. Solid surface was first introduced by DuPont in 1967 under the name of Corian. Since the expiration of their patent, other manufacturers have also introduced their brands as well. Solid surface is a non-porous low-maintenance material used for surfaces such as countertops. It can mimic the appearance of granite, marble, stone, and other naturally occurring materials, and can be joined nearly invisibly by a trained craftsman. Typically