How and why has our estimate of the size of the universe changed in the past few centuries?

"Centuries" is a long time, especially considering the speed at which science has advanced recently! The capacity to observe more of our universe has allowed us to shift from understanding the earth-centered small sphere of celestial bodies to the uncharted territory of the expanding universe.

People are typically "ignorant," not "stupid." We sometimes laugh at outdated ideas, but in reality, they were the best and most accurate explanations of the phenomena that could be observed. As new information was discovered through improved optics and later electronics, human observers were quick to adjust their theories whenever more accurate ones were suggested. The opposition from the social and political establishment was motivated differently than it is now.

Perhaps the greatest scientific breakthrough in history was the realization that "The Science is NEVER'settled' "! If you hear that it is - it is not a real scientist talking. We also know that we still do not exactly know what the size, shape, or even movement of the universe is.

The cosmos was once thought to be relatively small and geocentric, but observations by astronomers like Galileo and Copernicus challenged this theory and suggested that the Earth revolved around the Sun, expanding the perceived size of the cosmos. Later, discoveries by astronomers like Edwin Hubble and the development of telescopes and space probes provided evidence of the vastness of the universe, leading to the concept of an expanding universe governed by the Big Bang theory. As technology improved, astronomers could observe distant galaxies and cosmic phenomena