Hi, I´m new. I actually found this board with the message about speculative theory about the density of space and its relation to time but I see that post is two years old. Anyway I have another simple question that I just can´t find the answer to. What determines the direction of torque!!!? Is this just an unexplained phenomenon of the universe? I understand that the torque direction of all natural materials can be determined by using the right-hand rule. However, the left hand rule is also used but only for certain man-made left-handed or negative index materials. I also understand this is related to "metamaterials" which have a negative refractive index and are not natural but man-made. Are there any natural occuring materials that use the left-hand rule for torque but are not metamaterials (i.e. have a normal refractive index but still use the left-hand rule for torque)? What is determining this direction, and why do all natural materials use the right hand rule?