Breakwater, artificial offshore structure protecting a harbour, anchorage, or marina basin from water waves. Breakwaters intercept longshore currents and tend to prevent beach erosion.
photosphere. luminous, apparently opaque layer of gases that forms the visible surface of the sun sun,intensely hot, self-luminous body of gases at the center of the solar system.
Because it is a fairly thin region and the Sun is quite far away, the photosphere appears to be a very sharp surface, and gives the illusion of an actual surface. For that reason, the photosphere is considered to be both the lowest part of the solar atmosphere, and the surface of the Sun.