The hairy ball theorem insists that this field must drop to zero somewhere, which implies a disturbance in the antenna’s signal.

Learn more about Pythagoras' theorem with this BBC Bitesize Maths article. For students between the ages of 11 and 14.

Here's a curious consequence of the hairy ball theorem: there will always be at least one point on Earth where the wind isn't blowing across the surface. The wind flows in a continuous circulation ...

The lattice vectors describing the two-dimensional FLL lie perpendicular to the direction of magnetic induction , and by itself each lattice vector must satisfy the HB theorem.