Hi Leonid,

Wow! This is a mind-blowing demonstration that, in mathematics (and elsewhere), we tend to take our reference framework for granted ... and that, if we are able (in this case, definitely thanks to you :-)) to recognize that we are using a reference framework it allows us to change and open our mind, making it (hence us) more free. Thank you!

#thinkoutsidethebox
#helicopterview
#originality