Sacks: Aristarchus and Heliocentrism, Regression and Forgetting

from -- Oliver Sacks, The River of Consciousness (2017)

p. 204

… a most momentous regression in the history of astronomy. Aristarchus, in the third century B.C., clearly established a heliocentric picture of the solar system  that was well understood and accepted by the Greeks. [It was further amplified by Archimedes, Hipparchus, and Eratosthenes.] Yet Ptolemy, five centuries later, turns this on its head a proposed geocentric theory of almost Babylonian complexity . the Ptolemaic darkness, the scotoma, lasted 1,400 years until a heliocentric theory was  reestablished by Copernicus.

Scotoma, surprisingly common in all fields of science, involves more than prematurity; it involves a loss of knowledge, a forgetting of insights than once seemed clearly established, and sometimes a regression to less perceptive explanations. What makes an observation or a new idea acceptable, discussable, memorable? What may prevent it from being so, despite its clear importance and value?