A fatal flaw with Ptolemy's model is its inability to predict the observed phases of

Question

Quizplus · Accepted Answer

Ptolemy's model, which placed Earth at the center of the universe, could not accurately predict the observed phases of Mercury and Venus. This is because his geocentric model did not account for the fact that these planets orbit the Sun inside Earth's orbit, leading to specific phases similar to those of the Moon, which were later correctly explained by the heliocentric model of Copernicus.

A Fatal Flaw with Ptolemy's Model Is Its Inability to Predict