Predate rationalism? Modern rationalism and the scientific method came up in the 16th and 17th centuries, and was built on ancient foundations.

Phlogiston theory was developed in the 17th century, and took about 100 years to gather the evidence to make it infeasible, after the discovery of oxygen.

Luminiferous aether was disproved beginning in the late 19th century and the nail in the coffin happened by the early 20th, when Einstein's theories really started taking off.

Plate tectonics was entirely a 20th century theory, and became accepted in the second half of the 20th century, by people who might still be alive today.