Five hundred years ago, Nicolaus Copernicus proposed Earth orbits the Sun. He compared the geocentric model to Frankenstein’s monster—a patchwork of parts. The geocentric model matched the sky with dials for retrograde motion. Copernicus saw outer planets—Mars, Jupiter, Saturn—might loop due to parallax. He lacked physics from Isaac Newton or Albert Einstein. His model still had knobs due to circles, not ellipses. Yet he paved the way for simpler explanations.

In hindsight, broken symmetries—our off-centre view and non-uniform motions—complicate appearances within a simpler framework. Similarly, the standard cosmological model today resembles Frankenstein’s monster: an amalgam of ad hoc patches. After a century, it still affords no explanation of why our universe should expand.

Why should our universe expand? In the Copernican tradition, we ought to ask. The standard model offers no such explanation. It rests on a principle promoted by Einstein and Willem de Sitter: the universe expands despite deceleration from all we see. Galaxies and light work against expansion; anything driving it is an ad hoc dial. This tendency blows up at the Big Bang. The model’s only “explanation” is that expansion began with tremendous momentum against its natural tendency.