The Same Color Illusion.

Are squares A and B the same color? They are! To verify this, either run your cursor over the image or click here to see them connected. The featured illusion , an example of the same color illusion , illustrates that purely human perceptions in science may be ambiguous or inaccurate, even such a seemingly direct perception as relative color. Similar illusions exist on the sky , such as the size of the Moon near the horizon , or the apparent shapes of astronomical objects . The advent of automated, reproducible measuring devices such as CCDs have made science in general and astronomy in particular less prone to, but not free of, human-biased illusions .

APOD Year in Review (2023): RJN's Night Sky Network Lecture