Slight deviations are caused by inhomogeneities of subsurface structure. Wind shear and thermocline produce such inhomogeneities. These inhomogeneities are localized differences in optical path length that cause light deviation. Electron microscopy can also be used to demonstrate lateral inhomogeneities in biomembranes. His recent research has centered on issues of mass inhomogeneities and topological quantum field theories. Schlieren physics developed out of the need to produce high-quality lenses devoid of these inhomogeneities. The material inhomogeneities or defects cause then a distortion of temperature field. Shock waves typically have moving magnetic inhomogeneities both preceding and following them. A recent review by Trewin focused on the causes of inhomogeneities. Also other climate elements suffer from inhomogeneities.