Originally Posted by Dan Winterland
The Earth is ana oblate spheroid, fatter at the equator due to rotation.
The shortest track between two points is actually a rhumb line.
A great circle is the largest circle that can be made on the earth. This is if you think about it, the same as a rhumb line. Although, now we know the Earth is an oblate spheroid, this would technically have to be drawn along the eqatuor.
I must get out more
Just so we are not confusing program, What do you mean the shortest track? I am not putting words in your mouth, but I just want to say that the rhumb line isn't the shortest
distance between two points.
A Great circle is essentially the circumference of the earth, assuming the earth is round.