Curvature of the Horizon in High-Altitude Balloon Footage

High-altitude balloon footage is often abused by flat-Earthers to show us that the Earth is flat when seen from a high altitude.

We analyzed more than two dozens of footage taken from high-altitude balloons on YouTube, and we can easily conclude the curvature is there and usually easy to spot, including in the cases where flat-Earthers use the video as ‘proof’ of a flat Earth.

The majority of the ‘evidence’ are screenshots taken from these videos. The original videos were usually taken using fisheye lenses. In these videos, there are moments where the horizon appears flat, convex and concave. Their M.O. is to cherry-pick moments where the horizon appears flat and present them as the ‘evidence’ of the flat Earth, ignoring the fact it appears concave and convex in many other moments in the video.

To analyze the videos, we try to find a moment where the horizon crosses the center point of the image. In this case, if the horizon is flat, it should appear flat. And conversely, if the horizon is curved, then should appear curved. This method works even if a fisheye was used to take the video. A straight line will always appear straight when it crosses the center, regardless of the lens being used.

We analyzed over two dozens of high-altitude balloon footages on YouTube, and the curvature is there every single time. These videos are definitely not proof of a flat Earth. On the contrary, they are evidence that the Earth is spherical.

Videos Used in the Illustration

These are links to the videos used in the illustration.