Siamese cat including the Cornish Rex, Sphynx, Peterbald, and the blue point Siamese cat. The Siamese cat comes in two distinct variations: traditional, with an apple-shaped head and a slightly chubby body; or the modern Siamese, which are very skinny and have a wedge-shaped head. Both a description and depiction of the Wichienmaat (Siamese cat) first appears in a collection of ancient manuscripts called the Tamra Maew (The Cat-Book Poems) thought to originate from the Ayutthaya Kingdom (1351 to 1767 AD). Over a dozen are now kept in the National Library of Thailand, while others have resurfaced outside of Thailand and are
Point source source decreases in proportion to the inverse square of the distance from the source, if the distribution is isotropic, and there is no absorption or other loss. In mathematics, a point source is a singularity from which flux or flow is emanating. Although singularities such as this do not exist in the observable universe, mathematical point sources are often used as approximations to reality in physics and other fields. Generally, a source of light can be considered a point source if the resolution of the imaging instrument is too low to resolve the source's apparent size. There are two types