Sundial; our notion of time is inextricably linked to the observed 180 degree arc path of the sun. The modern notion of time descends from that, and fails to st

Sundial; our notion of time is inextricably linked to the observed 180 degree arc path of the sun. The modern notion of time descends from that, and fails to stand on its own, despite silly attempts to define SI units via ad hoc correspondances.