What the experiments actually show.

The Bedford Level Experiment (1838)

Experimenter: Samuel Birley Rowbotham
Location: Old Bedford River, England (a six-mile straight artificial waterway)
Procedure: A flag was placed at the far end of the six-mile stretch. Rowbotham observed it through a telescope from the other end at water level.
Predicted by globe model: The flag should drop ~24 feet below line of sight due to curvature.
Observed: The flag remained visible at original height.

Rowbotham documented the experiment in Earth Not a Globe (1881). It was repeated and refined under varying conditions over the following decades.

The Wallace Reproduction (1870)

Alfred Russell Wallace — co-discoverer of evolutionary theory with Darwin — accepted a £500 wager from a flat-earther named John Hampden to definitively prove curvature on the same Bedford Level stretch. Wallace set up three markers at equal heights along a 6-mile line. On a globe, the middle marker should be visibly higher than the two ends.

The result: the middle marker was higher than expected on a flat plane — but lower than a globe predicted. Wallace claimed victory. Hampden disputed the finding. The dispute went to court (Wallace won the legal action but the wager was disputed for years).

The actual measurement, on examination, showed the markers in a configuration consistent with atmospheric refraction over a flat plane — not consistent with a clean 6-foot drop predicted by sphere geometry. Both sides claimed victory. The experiment was technically inconclusive, but it failed to cleanly demonstrate curvature.

Lady Blount's Photographic Confirmation (1904)

Elizabeth Anne Mould Williamson (Lady Blount) repeated the Bedford Level experiment with photographic documentation in 1904. Her photographs, taken with a calibrated camera at water level, showed the far flag at original height — not curved out of view as the globe model would have predicted.

The photographs are reproduced in her published account and have been examined by independent reviewers. They constitute the first photographic record of the flat-water observation.

The Chicago Skyline Observations (Modern)

Joshua Nowicki and other photographers have documented the Chicago skyline as visible from points along the Michigan shore at distances of 50–60 miles. On a globe, the bottom 1,400+ feet of the skyline should be hidden. Time-lapse footage shows the entire skyline, with surface features at the base of buildings visible.

Frequency of the observation, time of day, atmospheric conditions, and observer height are all documented. The official explanation is "looming" — an extreme refraction event. The phenomenon's regularity exceeds what looming alone can plausibly account for.

The Salton Sea Tests (2014–2018)

Multiple independent observers conducted long-distance laser tests across the Salton Sea (California) at distances of 4–7 miles. With observer and target at matched heights, the laser was visible at the far point — inconsistent with curvature drop, consistent with a flat surface within measurement tolerance.

The Cavendish Experiment Replications

The Cavendish torsion-balance experiment (1798) is the foundational measurement of the gravitational constant G, from which Earth's mass is calculated. The original measurement has been "replicated" hundreds of times — but always under controlled conditions where electrostatic, vibrational, and observer-bias effects are difficult to fully isolate.

Modern critical reviews of Cavendish replications (see Mikulecky 2007, others) note that no replication has achieved the original's claimed precision under truly independent conditions. The experiment's central claim — that small lateral attraction between dense masses is gravitational rather than electromagnetic or environmental — has not been cleanly demonstrated.

The Sigma Octantis Problem

The Southern Cross constellation is observable from points across the Southern Hemisphere — Australia, South America, southern Africa, Madagascar. On a sphere, observers at sufficient latitudinal separation should see the constellation in significantly different positions due to parallax. In practice, the constellation appears in roughly consistent relative position to the south horizon across all observation points.

This is documented in pre-1700 navigation tables, which used the southern stars for celestial navigation across vast distances assuming a flat plane.

What the Record Shows

Two centuries of experimental record contains observations that the heliocentric model can only accommodate through aggressive use of atmospheric refraction, lens distortion, and observer-error explanations. The flat-plane model accommodates the same observations as direct readings.

This does not "prove" flatness. It does demonstrate that the case is not as closed as public education suggests.