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.
The Photosphere and Sunspots. The visible glowing surface of the sun is more appropriately called the photosphere, and it has a darker edge, called a 'limb.' It's darker because the temperature in the sun's photosphere decreases outward.either the photosphere nor the interior of the sun is solid-it's gaseous instead. A sunspot is a relatively dark spot on the sun with a lower temperature than the other parts of the photosphere. Sunspots occur in places where the magnetic field in the photosphere is many times stronger than average.