Extinction paradox

In the small wavelength limit , the total scattering cross-section of an impenetrable sphere is twice its geometrical cross-sectional area (which is the value obtained in classical mechanics).

Several explanations for this phenomenon have been proposed:
destructive interference inside particle shadow
diffraction and shadowing of light by particle
incident wave must be cancelled inside particle
superposition of incident and scattered field

References 

Category:Paradoxes