Curvature App

Curvature App is a web application we can use to create a simulation of the horizon’s shape and the visibility of distant objects on a flat and spherical Earth. Curvature App is available at

When determining a distant object’s visibility, flat-Earthers often use wrong calculators that fail to account for all the important variables and give them incorrect results. Curvature App accounts for all of these variables, and not only it gives us the numbers, but also the simulated view.

In this app, we can adjust the observer’s height, object’s size & distance, and atmospheric refraction strength. We can also alter the field of view (or the camera’s focal length), create a row of distant objects, add a second set of objects, etc.

From these inputs, the app will give us the observer’s simulated view, like the shape of the horizon, left-right drop, the dip of the horizon, the appearance of the objects, and their obstruction by Earth’s curvature.

The app also has several demos to explain some of the popular flat Earth talking points, like the Lake Pontchartrain power lines and Bedford Level, showing that all of these observations are consistent on a spherical Earth.