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lwymarie
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why latitudes are not parallel to each other but longitudes are?
look at a globe, think about it.lwymarie said:why latitudes are not parallel to each other but longitudes are?
That is a definition from PLANE geometry. The surface of the Earth is not a plane it is a sphere.lwymarie said:but I've heard a definition of 'parallel': if line A is perpendicular to both line B and line C, then line B and line C are parallel.
since the equator is parallel to every longitude, so longitudes are parallel?
[edit:misread]lwymarie said:but I've heard a definition of 'parallel': if line A is perpendicular to both line B and line C, then line B and line C are parallel.
since the equator is parallel to every longitude, so longitudes are parallel?
Both sets of lines are referenced to the same source: the Earth's rotational axis. But one is parallel, while the other is perpendicular. Latitude lines slice the Earth along planes perpendicular to the axis while longitude slice the Earth along planes that pass through the axis. Latitudes form parallel concentric rings. Longitudes form slices, like an orange.lwymarie said:why latitudes are not parallel to each other but longitudes are?
DaveC426913 said:(...)Latitudes form parallel concentric rings. (...)
lwymarie said:but I've heard a definition of 'parallel': if line A is perpendicular to both line B and line C, then line B and line C are parallel.
since the equator is perpendicular to every longitude, so longitudes are parallel?
This is starting to hurt my head - latitude lines are parallel, longitude lines are not. Longitude lines are perpendicular to the equator.lwymarie said:so why don't the geographers design parallel longitudes but non-parallel longitudes?
also, no matter the longitudes are parallel to each other or meet at the poles, they are parallel to the equator. Doesn't it sound odd?
Its fine, but what the others are saying (I'll say it another way) is that lines traced on the surface of the Earth are no longer lines, they are curves. When drawing maps, we pretend the Earth is flat (generally - most maps are Mercator projections), but it isn't.and my definition of parallel (if line A is perp. to both line B and line C, then B and C are ll) is not correct?
Right. Which is what makes them concentric - they all have the same centre (well, in two dimensions anyway.) They are concentrioc circles that have been translated along the axis.dextercioby said:Not really,u see the certers of the circles lie (actually form) the polar axis...Daniel.
lwymarie said:so why don't the geographers design parallel longitudes but non-parallel longitudes?
In elliptic geometry, the lines "curve toward" each other, and eventually intersect; therefore no parallel lines exist in elliptic geometry.
Gokul said:(...)Parallel latitudes, and great circle longitudes designate respectively, the polar and azimuthal angles. These are none other than the and of a spherical co-ordinate system.(...)
They are not numerically identical, but that's just a change in the numbering convention (choosing the equator instead of the NP as the zero). The concept is the same though.dextercioby said:Gokul,u induced the confusion that the azimuth [itex] \vartheta [/itex] and the lattitude [itex] \lambda [/itex] are one & the same angle,hence measured the same way,which is not true.So let's mix the mathematicians and the geographers's conventions,okay?
Daniel.
Latitude and longitude create a natural frame of reference in which the axes (the Earth axis and a line perpendicular to it from the centre of the Earth to the Greenwich meridian) change in a very understandable and predictable way relative to the sun or the stars. Knowing how they change, allows one to determine position accurately.lwymarie said:so why don't the geographers design parallel longitudes but non-parallel longitudes?
also, no matter the longitudes are parallel to each other or meet at the poles, they are parallel to the equator. Doesn't it sound odd?
Latitudes are not parallel to each other because they represent the distance from the equator, which is a curved line on a spherical Earth. On a flat map, this curvature is distorted, making the latitudes appear curved.
Latitudes and longitudes are both imaginary lines that help us locate places on Earth. The main difference is that latitudes run parallel to the equator, while longitudes run perpendicular to the equator and converge at the poles.
Longitudes are parallel to each other because they are based on a fixed reference point, the Prime Meridian, which runs through the North and South poles. Unlike latitudes, which are based on the curvature of the Earth, longitudes are straight lines that do not change in relation to each other.
Latitudes and longitudes are measured using degrees, minutes, and seconds. Latitudes range from 0° at the equator to 90° at the North and South poles. Longitudes range from 0° at the Prime Meridian to 180° at the International Date Line.
Latitudes and longitudes are essential for navigation because they provide a precise system for locating any place on Earth. They are used in GPS systems, maps, and navigation tools to determine one's location and to plan routes for travel.