Hi All, This is a question that has been bugging me for a few years now. How can we tell left vs right without using something else as reference? The same applies for clockwise vs anti-clockwise. For example, the way I can tell left and right is by relating to my body. If I was a point particle, how do I tell left vs right and clockwise vs counter-clockwise? Particles have the concepts of chirality and helicity (which I don't understand by the way) that seem to be related to knowing left vs right. How do they "know"? Similarly, how does the magnetic field "know" which way to align based on the direction of the electric current? Can anyone shed some light on this? Any comments are much appreciated.