IDK about physics, but AIUI, Z points from side to side, Y points down and X points diagonally; it's Λ that points up.
(sorry) Russell On 1 March 2018 at 08:43, Greg Ewing <greg.ew...@canterbury.ac.nz> wrote: > Daniel Pope wrote: > > Y points up in real physics? >> > > No, no, no. Z points up in real physics! > > -- > Greg >