In 1951, scientist Adelbert Ames invented the "Ames Window," an optical illusion involving a rotating, trapezoidal window that appears to oscillate back and forth instead of spinning continuously. This illusion demonstrates that the brain relies heavily on learned assumptions, such as the expectation that windows are rectangular, overriding actual visual data to construct a familiar, though incorrect, perception of reality. Credit: Dr. Deane Hutton and Dr. Rob Morrison | History In Pictures