(anatomy) A transverse plane at right angles to the longitudinal axis of the body.
On this page
McGraw-Hill Science & Technology Dictionary:
horizontal plane |
(anatomy) A transverse plane at right angles to the longitudinal axis of the body.
|
Featured Videos:
|
McGraw-Hill Dictionary of Architecture & Construction:
horizontal plane |
A plane perpendicular to the direction of a plumb line.
Oxford Dictionary of Sports Science & Medicine:
transverse plane |
A cardinal plane running horizontally at right angles to the longitudinal axis of the body, dividing it into superior (top) and inferior (bottom) halves.
Mosby's Dental Dictionary:
horizontal plane |
A plane that is parallel to the horizon and perpendicular to the vertical plane.
Wikipedia on Answers.com:
Horizontal plane |
|
|
This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2009) |
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.
Although the word horizontal is common in daily life and language (see below), it is subject to many misconceptions.
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 measurable and can be predicted with great accuracy, but they may not greatly affect our daily life.
This dichotomy between the apparent simplicity of a concept and an actual complexity of defining (and measuring) it in scientific terms arises from the fact that the typical linear scales and dimensions of relevance in daily life are 3 orders of magnitude (or more) smaller than the size of the Earth. Hence, the world appears to be flat locally, and horizontal planes in nearby locations appear to be parallel. Such statements are nevertheless approximations; whether they are acceptable in any particular context or application depends on the applicable requirements, in particular in terms of accuracy.
In graphical contexts, such as drawing and drafting on rectangular 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 slanted) table. In this case, the horizontal direction is typically from the left side of the paper to the right side. This is purely conventional (although it is somehow 'natural' when drawing a natural scene as it is seen in reality), and may lead to misunderstandings or misconceptions, especially in an educational context.
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
| horizontal angle | |
| vertical | |
| horizontal bracing |
| What plane of motion is horizontal flexion in? Read answer... | |
| What is a fold in which the axial plane is horizontal? Read answer... | |
| Where did the Frankfort horizontal plane get its name? Read answer... |
| Can two horizontal planes intersect? | |
| What is another name for horizontal plane? | |
| What does the horizontal stabilizer do on a plane? |
Copyrights:
![]() |
![]() | McGraw-Hill Science & Technology Dictionary. McGraw-Hill Dictionary of Scientific and Technical Terms. Copyright © 2003, 1994, 1989, 1984, 1978, 1976, 1974 by McGraw-Hill Companies, Inc. All rights reserved. Read more |
![]() |
![]() | McGraw-Hill Dictionary of Architecture & Construction. McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc. All rights reserved. Read more |
![]() | Oxford Dictionary of Sports Science & Medicine. The Oxford Dictionary of Sports Science & Medicine. Copyright © Michael Kent 1998, 2006, 2007. All rights reserved. Read more | |
![]() | Mosby's Dental Dictionary. Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved. Read more | |
![]() |
![]() | Wikipedia on Answers.com. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article Horizontal plane. Read more |