Rayleigh distance Rayleigh distance Rayleigh distance in optics is the axial distance from a radiating aperture to a point at which the path difference between the axial ray and an edge ray is λ / 4. An approximation of the Rayleigh Distance is formula_1, in which Z is the Rayleigh distance, D is the aperture of radiation, λ the wavelength. This approximation can be derived as follows. Consider a right angled triangle with sides adjacent formula_2, opposite formula_3and hypotenuse formula_4. According to Pythagorean theorem, formula_5. Rearranging, and simplifying formula_6 The constant termformula_7 can be neglected. In antenna applications, the Rayleigh distance is
Regular sound correspondences between Hungarian and other Uralic languages Regular sound correspondences between Hungarian and other Uralic languages There are numerous regular sound correspondences between Hungarian and the other Uralic languages. For example, Hungarian "á" corresponds to Khanty "o" in certain positions, and Hungarian "h" corresponds to Khanty "x", while Hungarian final "z" corresponds to Khanty final "t". These can be seen in Hungarian "ház" ("house") and Khanty "xot" ("house"), or Hungarian "száz" ("hundred") and Khanty "sot" ("hundred"). Hungarian and Khanty are closely connected, either genealogically or as part of a language area. The distance between Hungarian and the Finnic languages is greater, but the correspondences are also regular.