Behind the Curve: The Experiments That Disproved Themselves

The flat-Earthers' own experiments would confirm a flat Earth: a laser gyroscope should show no rotation, and a light sent across a flat surface at a fixed height should stay at that height.

The documentary 'Behind the Curve' (2018, dir. Daniel J. Clark; Netflix Feb 2019) follows the flat-earth community and films their own experiments. (1) Bob Knodel (GlobeBusters) buys a $20,000 laser gyroscope - the kind used in inertial navigation - and measures its drift. (2) Jeran Campanella's final experiment (the film's ending): two holes cut into styrofoam sheets at the same height over water; a light shone through the first hole should appear at the camera behind the second hole at the same height if the surface is flat.

The gyroscope drifts exactly 15 degrees per hour - the Earth's rotation rate: 'when we turned on that gyroscope we found that we were picking up a drift... Wow, that's kind of a problem.' And the light: at the same height it does NOT appear at the camera; 'Lift up your light, way above your head' - raised to compensate for curvature, it immediately appears. 'Interesting,' Campanella says. 'That's interesting.' (The film ends.)

Despite further refinements the gyroscope 'consistently behaves as if the Earth is round' - and at a meetup: 'We've got $20,000 in this freaking gyro. If we dumped what we found right now, it would be bad. What I just told you was confidential.' The model survived by moving the goalposts. The follow-up is the best part: Jeran Campanella - the 'That's interesting' guy - went to Antarctica in 2024 (see the TFE case) and finally admitted his model was no longer valid.

This is the pattern in its purest form, on camera: buy the instrument with your own money, run the experiment, get a spinning globe's rotation rate, and reject the result. Psychologists in the film explain why: the belief is an identity and a community - 'It becomes a question of identity. Who am I in this world?' Evidence cannot compete with belonging. (The film also features astronaut Scott Kelly and Neil deGrasse Tyson.)