Feynman talks about this in his "Symmetry" lecture, and how there's no way to discern "left" from "right" without a shared artifact. (You can try to get clever

Feynman talks about this in his "Symmetry" lecture, and how there's no way to discern "left" from "right" without a shared artifact. (You can try to get clever and use a magnet, but there's also no way to discern magnetic north from south without a shared artifact, so that's ultimately the same convention.) It's like how any complex number can only be a±bi; a+bi doesn't actually mean anything by itself.