# What is surface?

• (adj): Involving a surface only.
Example: "A surface wound"
Synonyms: skin-deep, superficial

## Surface

In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball. On the other hand, there are surfaces, such as the Klein bottle, that cannot be embedded in three-dimensional Euclidean space without introducing singularities or self-intersections.

### Some articles on surface:

... The field's surface, originally composed of AstroTurf, contained many gaps and uneven patches ... Baseball players also complained about the surface ... It was much harder than other AstroTurf surfaces, and the shock of running on it often caused back pain ...
Surfaces in Geometry
... Polyhedra, such as the boundary of a cube, are among the first surfaces encountered in geometry ... It is also possible to define smooth surfaces, in which each point has a neighborhood diffeomorphic to some open set in E² ... This elaboration allows calculus to be applied to surfaces to prove many results ...
Geodetic Datum
... In surveying and geodesy, a datum is a set of reference points on the Earth's surface against which position measurements are made and (often) an associated model of the shape of the ... datums are used for describing a point on the Earth's surface, in latitude and longitude or another coordinate system ... and drafting, a datum is a reference point, surface, or axis on an object against which measurements are made ...
... head is controlled by the design of an air-bearing etched onto the disk-facing surface of the slider ... the flying height constant as the head moves over the surface of the disk ... If the head hits the disk's surface, a catastrophic head crash can result ...
Roman Surface
... The Roman surface or Steiner surface (so called because Jakob Steiner was in Rome when he thought of it) is a self-intersecting mapping of the real projective plane into ... gives parametric equations for the Roman surface as follows x = r2 cos θ cos φ sin φ y = r2 sin θ cos φ sin φ z = r2 cos θ sin θ cos2 φ ... xy-, yz-, and xz-planes are tangential to the surface there ...

### More definitions of "surface":

• (verb): Appear or become visible; make a showing.
Example: "I hope the list key is going to surface again"
Synonyms: come on, come out, turn up, show up
• (noun): The outer boundary of an artifact or a material layer constituting or resembling such a boundary.
Example: "There is a special cleaner for these surfaces"; "the cloth had a pattern of red dots on a white surface"
• (noun): The outermost level of the land or sea.
Example: "Earthquakes originate far below the surface"; "three quarters of the Earth's surface is covered by water"
Synonyms: Earth's surface
• (noun): Information that has become public.
Example: "The facts had been brought to the surface"
Synonyms: open
• (noun): A superficial aspect as opposed to the real nature of something.
Example: "It was not what it appeared to be on the surface"
• (noun): The extended two-dimensional outer boundary of a three-dimensional object.
Example: "They skimmed over the surface of the water"; "a brush small enough to clean every dental surface"; "the sun has no distinct surface"
• (verb): Put a coat on; cover the surface of; furnish with a surface.
Synonyms: coat
• (noun): A device that provides reactive force when in motion relative to the surrounding air; can lift or control a plane in flight.
Synonyms: airfoil, aerofoil, control surface