What does Immanuel Kant's Copernican Revolution all about?

Answer 1

Good question. I like that idea! Kant's Copernican Revolution is his example of a state of perplexity: a new world view was necessary to cope with the drastic changes (in this case: drastic changes in the knowledge on the structure of the universe).
The same can be said about the discovery of the 'new world', that also meant a big clash with the current and consistent world view, and, according to some, the introduction of the internet.
It takes time for a people to adapt, and for a society to rearrange their beliefs in a consistent order, so all dimensions of reality can be incorporated in one rational world theory.

Answer 2

It is an analogy.

Before Copernicus our explanation of astronomical movements was on the basis of Ptolemy, and really a whole lineage of others who hypothesized the Earth as the center of the universe. They were able to predict the periodic rising and falling of stars given the notion of epicycles. The system worked fairly well-- Ptolemy is still used for navigation today.

But Copernicus hypothosized the Sun as the center of the universe, and that changed our view of astronomy entirely. It didn't happen overnight, because both hypothoses were supported by the data, but Copernicus ultimately needed less epicycles to explain the movement of the planets and stars.

Kant thinks his philosophic project is analagous to this scientific revolution, from geocentrism to heliocentrism, instead we are organizing our knowledge and the conditions for the possibility of knowledge around human cognition, turning inward. Instead of insisting on a Cartesian world of extended objects that are only ever act on our passive senses-- and we, forming representations on the basis of these impressions-- Kant changes the paradigm of what we call reality. We humans bring concepts to the raw sensory data in order to perceive it; we are active in perception. Time, space, causality, which were all thought to inhere in the objects are brought to them by us. Outside of our particular way of making sensible the world, we cannot posit uncognized objects, or things-in-themselves; they are unintelligible without existing in time and space, etc. That makes what is truly real the empirical world-- what we experience -- which we thankfully have a grasp of, whereas we used to think the true ground of reality was always outside our sensation, which lead inexorably to skepticsm, since we could never get outside our perception.