The shortest distance between two points is a straight line. This is one of the basic principles of Euclidean geometry. But we live on a spherical Earth, so we cannot travel the straight line path ...

One hypothesis about the shape of the universe is that the universe is in the space of Euclidean geometry and flat. In Euclidean geometry, it is assumed that straight lines extend everywhere, planes ...

All human beings may have the ability to understand elementary geometry, independently of their culture or their level of education. In a spherical universe, researchers found that Amazonian Indians ...

Every nonconstant meromorphic function in the plane univalently covers spherical discs of radii arbitrarily close to arctan $\sqrt 8 \approx$ 70 ⚬ 32'. If in addition all critical points of the ...