Ponzo's Illusion

The upper Horizontal line segment in the above figure appears to be longer than the lower line segment despite the factthat both are the same length.

References

Fineman, M. The Nature of Visual Illusion. New York: Dover, p. 153, 1996.

• Gauss's Circle Problem
• Gauss's Class Number Conjecture
• Gauss's Class Number Problem
• Gauss's Constant
• Gauss's Criterion
• Gauss's Double Point Theorem
• Gauss's Equation (Radius Derivatives)
• Gauss's Formula
• Gauss's Formulas
• Gauss's Forward Formula
• Gauss's Harmonic Function Theorem
• Gauss's Hypergeometric Theorem
• Gauss's Inequality
• Gauss's Interpolation Formula
• Gauss's Lemma
• Gauss's Machin-Like Formula
• Gauss's Mean-Value Theorem
• Gauss's Polynomial Theorem
• Gauss's Reciprocity Theorem
• Gauss's Test
• Gauss's Theorem
• Gauss's Theorema Egregium
• Gauss's Transformation
• Gear Graph
• Gegenbauer Function