In geometry, physics, astronomy, geography, and related sciences, a plane is said to be horizontal at a given point if it is perpendicular to the gradient of the gravity field at that point— in other words, if apparent gravity makes a plumb bob hang perpendicular to the plane at that point.
In radio science, horizontal plane is used to plot an antenna's relative field strength in relation to the ground (which directly affects a station's coverage area) on a polar graph. Normally the maximum of 1.000 or 0 dB is at the top, which is labeled 0o, running clockwise back around to the top at 360°. Other field strengths are expressed as a decimal less than 1.000, a percentage less than 100%, or decibels less than 0 dB. If the graph is of an actual or proposed installation, rotation is applied so that the top is 0o true north. See also the perpendicular vertical plane.
In general, something that is horizontal can be drawn from left to right (or right to left), such as the x-axis in the Cartesian coordinate system.
Other articles related to "planes, horizontal plane, plane, horizontal, horizontal planes":
... Many features observed in geology are planes or lines, and their orientation is commonly referred to as their attitude ... direction of the line, and the plunge is the downward angle it makes with a horizontal plane ... For a plane, the two angles are called its strike (angle) and its dip (angle) ...
... vision work of Ptolemy and discovered that objects lying on a horizontal line passing through the fixation point resulted in single images, while objects a reasonable distance from this line resulted in ... only later that this line was shown to actually be a circular plane surrounding the viewer's head ... Müller made a similar conclusion for the horizontal plane containing the fixation point, although he did expect the horopter to be a surface in space (i.e ...
... The concept of a horizontal plane is thus anything but simple, although, in practice, most of these effects and variations are rather small they are ... Hence, the world appears to be flat locally, and horizontal planes in nearby locations appear to be parallel ... paper, it is very common to associate one of the dimensions of the paper with a horizontal, even though the entire sheet of paper is standing on a flat horizontal (or ...
Famous quotes containing the words plane and/or horizontal:
“with the plane nowhere and her body taking by the throat
The undying cry of the void falling living beginning to be something
That no one has ever been and lived through screaming without enough air”
—James Dickey (b. 1923)
“And yet out of eternity, a thread
separates itself on the blackness,
a horizontal thread
that fumes a little with pallor upon the dark.”
—D.H. (David Herbert)