What is the best metaphor for bad science? Usually, when someone wants to mock some idea as bad science, they compare it to flat Earth theory, geocentrism, or aether theory.
The trouble is that none of these comparisons work. The ancient Greeks understood that the Earth was round, and it is not true that Columbus was needed to disprove the flat Earthers.
Geocentrism is not really wrong, as relativity teaches that any frame of reference can be used. Aether theory is not really wrong either, as there are several physics concepts that can be legitimately presented as a modern aether.
Ancients said that everything was composed of earth, water, air, and fire. This is a gross oversimplification, but not necessarily an error. A combustible substance called phlogiston was also just an oversimplification.
The alchemist desire to turn lead into gold was fruitless, but it was not an error to speculate that lead and gold were made of the same ingredients. They are. We can't blame them for not knowing how large the nuclear forces are.
Aristotle is mocked for saying that heavier objects fall faster than lighter objects, but he didn't really say that. Also, denser objects do fall faster if air resistance is significant.
Celestial epicycles are cited as a methodological error, but it is very hard to justify that view.
So what example should we be using for bad or erroneous science? Any suggestions?