Svetlana wrote:Maybe GR will be along shortly to explain all of this - and then no-one will understand what is going on

Lana

“j” is the operator used in mathematics (complex numbers) to represent the square root of -1 that would otherwise return a positive number (-1 x -1 = 1) thus rendering it incorrect. By the same token, the square root of -4 is (2 x j) and not 2!

In some countries they call this imaginary number the “i” operator, so I guess our friend here is trying to perplex us with complex number theory!

Do you understand?