What are the great circles of earth?

Answer 1

A great circle is a circle on a sphere that divides the sphere into two equal halves. It is the longest distance that can be traveled on the surface of a sphere. The equator can be described as a great circle, as can each line of longitude. See the related link for more information.

A great circle route is the shortest distance between any two points on the earth, and is always a curve on a plane containing the two points and the center of the earth. It is the largest possible circle that can be made on the earth's surface that contains the two points.

Answer 2

A great circle is a line drawn on a globe (or sphere) that divides it into two equal halves. A great circle arc (a segement of a great circle) is always the shortest distance between two points on the Earth. Since the Earth is a globe, that is not equivalent to a straight line on a map.

For example, if we draw a line on a Mercator's projection map (a "rhumb line") from New York to Tokyo, it will go straight across the country, through California, near Hawai'i, and on to Japan. However, if we take a string and put one end on a globe at New York and the other on Tokyo, the line will pass through Canada and Northern Alaska. That is actually the shortest route.

There are infinitely many great circles on the earth's surface; any two points on earth are connected by at least one. But the great circles that are easily identified are the equator, and any possible line of longitude, paired with its partner on the other side of the poles, 180 degrees of longitude over.

If the two points are antipodal (exactly opposite each other on the globe, like the north and south poles) then like the poles, infinitely many great circles contain them.

Answer 3

A great circle is a circle on the surface of a sphere whose center is at the center of the sphere.

The shortest distance between two points on the surface of a sphere (like the Earth

for example) is the piece of the great circle that joins them. If you're flying, then that's

the route you want to follow.

Answer 4

The great circles of Earth are lines formed when a plane passes through the center of the Earth, dividing it into two equal halves. The equator and lines of longitude are examples of great circles on Earth. They are the largest circles that can be drawn on a sphere.