Chapter 10

Almagest

A highly technical work by Ptolemy published around 150 CE, discussing the structure of the universe.

Aristotelian worldview

A view of the universe that includes beliefs such as the Earth being spherical, stationary, and at the center of the universe.

Spherical Earth

The belief that the Earth has a uniform curvature and is shaped like a sphere.

Stellar parallax

The apparent shift in the position of stars due to the observer's movement, which Ptolemy argued should occur if the Earth were moving.

Common-sense arguments

Arguments based on everyday observations that support the notion of a stationary Earth.

Disconfirmation reasoning

A form of reasoning where evidence against a hypothesis is used to argue that the hypothesis is false.

Natural place of Earth element

In Aristotelian theory, the belief that earthly materials tend to move towards the center of the universe.

Ptolemy's arguments for a stationary Earth

Arguments presented in the Almagest that support the idea that the Earth does not move, including the behavior of falling objects and the lack of stellar parallax.

Earth-centered universe

The belief that the Earth is at the center of the universe around which celestial bodies revolve.

Confirmation reasoning

A form of reasoning where evidence that supports a hypothesis is used to assert that the hypothesis is likely true.