new icn messageflickr-free-ic3d pan white
The Curve of the Earth | by Jeff Rose Photography
Back to photostream

The Curve of the Earth

Visit Our Website! II Facebook II Twitter II Tumblr

 

For image licensing requests or photo related questions click here! or message me through Flickrmail.

 

The eastern shore of England seen flying high above the English Channel

 

From a point above the surface the horizon appears slightly bent. There is a basic geometrical relationship between this visual curvature κ, the altitude and the Earth's radius.

 

The curvature is the reciprocal of the curvature angular radius in radians. A curvature of 1 appears as a circle of an angular radius of 45° corresponding to an altitude of approximately 2640 km above the Earth's surface. At an altitude of 10 km (33,000 ft, the typical cruising altitude of an airliner) the mathematical curvature of the horizon is about 0.056, the same curvature of the rim of circle with a radius of 10 m that is viewed from 56 cm. However, the apparent curvature is less than that due to refraction of light in the atmosphere and because the horizon is often masked by high cloud layers that reduce the altitude above the visual surface.

 

Visit our Website

Follow us on Facebook

 

 

7,189 views
52 faves
57 comments
Taken on June 3, 2011