A common statement, regarded as evidence for FET, is that the surface water on a placid water body remains flat and does not follow the curvature of the Earth. Since it is generally assumed that water takes the shape of its container, a flat surface of water therefore means a flat Earth. However, the water within a container, or any container (e.g. Earth) produces a meniscus when reacting to the container. This makes the waters of the earth slightly concave, but since they are measured to be flat, then the Earth-disc must be slightly convex to cancel out with the concavity.