Geometric centers

thumb|right|The epicenter is directly above the earthquake's [[hypocenter (also called the ).]]

A hypocenter or hypocentre, also called ground zero or surface zero, is the point on the Earth's surface directly below a nuclear explosion, meteor air burst, or other mid-air explosion. In seismology, the hypocenter of an earthquake is its point of origin below ground; a synonym is the focus of an earthquake.

unique point where the weighted relative position of a distributed mass sums to zero

rotational center of the Milky Way galaxy

middle point, in some sense, of an object in geometry

thumb|right|Centroid of a triangle

measure of two radii meeting

fixed reference point; special points with reference to which any of a variety of curves is constructed

center of mass of two or more bodies that are orbiting each other, or the point around which they both or all orbit

Geometric objects with a common centre

theorem that, for a solid of revolution of a planar figure, the surface area equals the figure’s perimeter times the distance the perimeter’s centroid travels, and the volume equals the figure’s area times the distance the figure’s centroid travels

term in Gaussian optics

the point where the total sum of a pressure field acts on a body

point at a distance from the curve equal to the radius of curvature lying on the normal vector

point on an aerodynamic surface at which the pitching moment coefficient for the airfoil does not vary with lift coefficient

frame of reference

In Fig. P is the point of rotation

in demography, the geographical point that describes the centerpoint of a specific area's population

measurement of the initial static stability of a floating body

intersection point of the three radical axes of the pairs of circles

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perpendicular impacts at the CoP will produce no reactive shock at the pivot of a rigid beam

point from which at least two geometrically similar figures can be seen as a dilation/contraction of one another

point over which the aircraft would balance

an notional point on a vehicle's longitudinal axis at which the turning forces in the suspension react to the vehicle body