Empirical Earth · How We Know — History & the Cosmos

Heliocentrism vs geocentrism — the evidence the Earth orbits the Sun

The claim

“Motion is relative, so geocentrism is just as valid as heliocentrism.”

What is true

Motion is relative, and kinematically you may pick any frame you like. Einstein did say no frame is privileged.

What is measured

Aberration (1729) proved the Earth moves; parallax (1838) proved it orbits. A Sun-centered, Newtonian solar system predicts both to the arcsecond; a stationary Earth predicts neither without inventing a daily-spinning, faster-than-light cosmos. The observation that ended pure geocentrism is the phases of Venus.

What would show this is wrong

a measured stellar parallax or aberration consistent with a stationary Earth, or phases of Venus matching the Ptolemaic (crescent-only) prediction.

Sources

  1. Stellar parallax and the aberration of starlight. James Bradley’s 1729 discovery of stellar aberration — an annual ~20-arcsecond shift of every star aligned with the Earth’s orbital velocity link
  2. The phases of Venus and the moons of Jupiter. Galileo’s 1610 telescopic observations showed Jupiter has four orbiting moons and that Venus runs through a full range of phases — from crescent link
  3. The TYCHOS model (claim source). Simon Shack’s geocentric “geoaxial binary” model, presented in full on the author’s own site, which places Earth at the center of a Sun–Mars binary. Linked s link
The full entry, with the working →

This is one card from Empirical Earth, a free reference that states each flat-Earth claim at its strongest and then answers it with sourced measurements. Nothing is for sale and there are no advertisements.