Isis (Ancient Greek: Ἶσις, original Egyptian pronunciation more likely Aset) is a goddess in Ancient Egyptian religious beliefs, whose worship spread throughout the Greco-Roman world. She was worshipped as the ideal mother and wife as well as the patron of nature and magic. She was the friend of slaves, sinners, artisans, and the downtrodden, and she listened to the prayers of the wealthy, maidens, aristocrats, and rulers. Isis is often depicted as the mother of Horus, the hawk-headed god of war and protection (although in some traditions Horus's mother was Hathor), and she is depicted suckling him in an attitude similar to that of the Virgin Mary with the Child Jesus. Isis is also known as protector of the dead and goddess of children.

The name Isis means "Throne". Her headdress is a throne. As the personification of the throne, she was an important representation of the pharaoh's power. The pharaoh was depicted as her child, who sat on the throne she provided. Her cult was popular throughout Egypt, but the most important sanctuaries were at Behbeit El-Hagar in the Nile delta, and, beginning in the reign with Nectanebo I (380–362 BCE), on the island of Philae in Upper Egypt.

In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.

The Earth's outer solid layer, the lithosphere, is made of rock. Three majors groups of rocks are defined: igneous, sedimentary, and metamorphic. The scientific study of rocks is called petrology, which is an essential component of geology.

Rocks are generally classified by mineral and chemical composition, by the texture of the constituent particles and by the processes that formed them. These indicators separate rocks into three types: igneous, sedimentary, and metamorphic. They are further classified according to particle size. The transformation of one rock type to another is described by the geological model called the rock cycle.

Igneous rocks are formed when molten magma cools and are divided into two main categories: plutonic rock and volcanic. Plutonic or intrusive rocks result when magma cools and crystallizes slowly within the Earth's crust (example granite), while volcanic or extrusive rocks result from magma reaching the surface either as lava or fragmental ejecta (examples pumice and basalt).

A wake is the region of recirculating flow immediately behind a moving or stationary solid body, caused by the flow of surrounding fluid around the body.

In fluid dynamics, a wake is the region of disturbed flow (usually turbulent) downstream of a solid body moving through a fluid, caused by the flow of the fluid around the body. In incompressible fluids (liquids) such as water, a bow wake is created when a watercraft moves through the medium; as the medium cannot be compressed, it must be displaced instead, resulting in a wave. As with all wave forms, it spreads outward from the source until its energy is overcome or lost, usually by friction or dispersion.

The formation of these waves in liquids is analogous to the generation of shockwaves in compressible flow, such as those generated by rockets and aircraft traveling supersonic through air (see also Lighthill equation). The non-dimensional parameter of interest is the Froude number.

For a blunt body in subsonic external flow, for example the Apollo or Orion capsules during descent and landing, the wake is massively separated and behind the body is a reverse flow region where the flow is moving toward the body. This phenomenon is often observed in wind tunnel testing of aircraft, and is especially important when parachute systems are involved, because unless the parachute lines extend the canopy beyond the reverse flow region, the chute can fail to inflate and thus collapse. Parachutes deployed into wakes suffer dynamic pressure deficits which reduce their expected drag forces. High-fidelity computational fluid dynamics simulations are often undertaken to model wake flows, although such modeling has uncertainties associated with turbulence modeling (for example RANS versus LES implementations), in addition to unsteady flow effects. Example applications include rocket stage separation and aircraft store separation.

A serpent is a synonym for snake.

Serpent or The Serpent may also refer to: