points by lioeters 10 hours ago

Funny how the so-called eldritch terror is another face of what is widely considered one of the most beautiful equations in mathematics, Euler's identity that unites five fundamental constants.

  e^(i*pi)+1 = 0

..which is a result of the more general formula.

  e^(i*x) = cos(x) + i*sin(x)

Pi is hiding there in the sin and cos functions implicitly, because the unit radian is defined by 2*pi. In comparison, the version you mentioned that takes x in "turns".

  -1^(2x) = cost(x) + i*sint(x)

It got rid of pi and e, which already seems a win for simplicity. i is still there for the imaginary component, or y in the complex plane. So the need for pi was removed thanks to the "turn", defined by 1 as the whole circle or cycle.

Multiplying -1 to itself every half turn makes it an alternating series of 1 and -1.. Weird, but it is visually clear to understand, without involving e. Though I still don't see where e went. Oh, this comment explains:

> If we rearrange the products in the exponent we get

    2πix          πi2x          (  πi ) 2x
  e         ->   e         ->   (e    )

> Where e^(πi) is -1. That shows there is something to the turns units; we can express the analog of the Euler identity using exponentiation using a base and factor which are integers.

Yeah I get it now, a "turn" acts like a dimensionless unit to the circle/cycle.