That’s fairly simple: we restrict the complex phase to the range (-pi, pi] and the principal square root halves the complex phase. -1 has the phase value pi, so the principal square root has the the complex phase pi/2, so it’s i, while -i has a phase of -pi/2

This is technically incorrect. While the square root is both the positive and the negative solution, the sqrt (√) operator results in the principal square root. For nonnegative numbers this is the nonnegative square root and more generalised for complex numbers it’s the square root that halves the complex phase.

Now I am confused. How is engineering disjunct from science? And even beyond that, there is astronomy involved (star map, eurion being based on Orion), which has something to do with science.

The eurion constellation is a security feature used on many banknotes. It’s made up from 5 circles and often integrated into larger patterns that make it less obvious. Printers identify it and reject to print money.

I like the idea but couldn’t you just go the more direct route and mine crypto?

I’m not American so I hadn’t heard of Kristi Noem before the last episode. But seeing this post, they were spot on

Except they paid someone to make them look like this

From that chart Qobuz seems to be the all round best deal. Is there any catch?

The limit was 140 characters which is also the reason why twitter originally had a 140 character limit: you were able to tweet by SMS