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### Non-euclidean geometry

Geometry that works with issues that are not directly observable or not intuitive understandable is referred to as **Non-euclidean geometry**.

##### Explanation

Euclidean geometry is named after the ancient Greek Euclid, who described the geometry that we see around us. It consists of points, lines, planes, triangles, circles, arcs, cubes, spheres, cylinders, etc. The mathematical rules that are used for this are described in axioms.

Also the rules for the non euclidean geometry are described in axioms. An exception forms that the axiom for Parallels is defined differently. There may exist infinitely many parallels or none at all. With the mathematical rules that emerge from that you can make calculations of physical phenomena that cannot be explained logically.

## HistoryIn mathematics the rules (aximoma's, postulates, etc.) must be logical and consistent. But there are things that we cannot imagine and where we want to perform calculations. Like, how big is infinity, how long lasts forever, and how much is nothing? By using non euclidean geometry, Albert Einstein was able to work out the theory of relativity. Quantum mechanics is not possible without this. The Italian mathematician Eugenio Beltrami (1835 - 1900) was the first to prove that non-euclidean geometry is consistent. |