Quandaries and Queries 

Who is asking: Student
Question: i know this deals with the curvature of earth, but i can't figure out the formulas involved. thanks! Hi Judy, In the diagram below r is the radius of the earth, approximately 3963 miles, and h is the height, in feet, of a person standing in the surface of the earth, and C is the center of the earth. First notice that the height of the person in miles is ^{h}/_{5280}. The line segment AB is the line of sight of this person to the horizon. Since AB is tangent to the circle, the angle CBA is a right angle. Thus, using Pythagoras' theorem, the length of AB is given by Thus a person 6 feet tall standing on level ground can see for about 3 miles. So, theoretically, a person 6' tall (with binoculars) should be able to see the top of the head of a sixfooter who is 6 miles away. He would see the whole person at a distance of 3 miles. Chris 

