From: ram@zedat.fu-berlin.de   
      
   ram@zedat.fu-berlin.de (Stefan Ram) writes:   
   >To better understand symmetries, I have a few questions, but for   
   >simplicity's sake I'll start with one:   
      
     And here's my other question:   
      
     It's about something I often encounter in texts about   
     symmetries, the point where I find it hard to follow.   
      
     Here's an example:   
      
   |Given a perfect circle, you can rotate it by a tiny amount   
   |and find that you still have the same circle.   
   "Why String Theory?" (2016) - Joseph Conlon (1981/)   
      
     . A kinematic "rotation", to me, is a change in the angular   
     position of an object. I think of a "circle" as a physical object,   
     a kind of very thin torus (a torus the minor radius of which   
     is much smaller than its major radius). A "perfect circle" is   
     perfectly homogeneous. It has no hair. So one cannot measure its   
     angular position (rotation around its center in its plane) (just   
     as you cannot measure the "angular position" of a Higgs boson,   
     i.e., in which direction it "points"). Since a perfect circle does   
     not have an angular position, it also cannot rotate kinematically,   
     contradicting the statement, "you can rotate it" from the   
     quotation. So, the quoted statement makes not sense to me.   
      
     Is my objection justified?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)