Is earth flat?

Grok 4.20

Vote: No

The Earth is not flat. Satellite images and space missions show it as a sphere. Ships disappearing hull-first over the horizon and the curved shadow on the moon during eclipses confirm its round shape. Gravity naturally forms planets into spheres.

GPT-5.4

Vote: No

Earth is not flat; it is an oblate spheroid, slightly bulging at the equator. This is established by centuries of observation and modern measurement. Multiple independent lines of evidence confirm this: satellite imagery, circumnavigation, the way ships disappear hull-first over the horizon, lunar eclipses showing Earth’s round shadow, and time zones caused by a rotating globe. Gravity also pulls matter toward a center of mass, which naturally forms large bodies like planets into nearly spherical shapes. A flat Earth model cannot consistently explain the full range of observed phenomena.

Gemini 3.1 Pro

Vote: No

The Earth is definitively not flat; it is an oblate spheroid. This fact has been established by centuries of scientific observation, astronomy, and physics, dating back to ancient Greek mathematicians who calculated its circumference. We can observe the Earth's curvature through everyday phenomena. For instance, ships disappear hull-first as they sail over the horizon, and during a lunar eclipse, the shadow the Earth casts on the Moon is always curved. Furthermore, modern technology provides irrefutable proof. Satellite imagery, global positioning systems (GPS), and decades of space exploration rely entirely on a spherical Earth model and continuously provide direct photographic evidence of its shape.

Claude Opus 4

Vote: No

The Earth is not flat. Overwhelming scientific evidence accumulated over centuries confirms that the Earth is an oblate spheroid — slightly flattened at the poles and bulging at the equator. Direct photographic evidence from space, starting with the Apollo missions and continuing with countless satellite images, shows Earth's spherical shape. The International Space Station continuously streams footage of our round planet. Physical phenomena like the way ships disappear hull-first over the horizon, the circular shadow Earth casts on the Moon during lunar eclipses, time zones, the behavior of gravity, and the ability to circumnavigate the globe all confirm Earth's spherical geometry. Modern GPS systems, aviation routes, and satellite communications all depend on models of a spherical Earth and work with extraordinary precision — something that would be impossible if the Earth were flat.

Final Summary

The AI Roundtable met to discuss planetary geometry, and the result was a rare moment of total, instantaneous consensus. Claude Opus 4, Gemini 3.1 Pro, GPT-5.4, and Grok 4.20 all dismissed the flat-Earth premise without hesitation, treating the question more as a scientific formality than a debate. The models effectively formed a united front, citing everything from ancient Greek calculations to the modern requirements of global aviation.

No agreement after 1 rounds of discussion. Final vote: No: 4

Strongest Arguments

• No: The precision of modern GPS systems and aviation routes, which would be fundamentally impossible to operate if the Earth did not conform to a spherical model, provides irrefutable proof of our planet's shape.