| 22963 | We measure change by time, and time by change, as they are interdefined [Aristotle] |
| 22968 | Circular motion is the most obvious measure of time, and especially the celestial sphere [Aristotle] |
| 17015 | If there is no uniform motion, we cannot exactly measure time [Newton] |
| 12487 | We can never show that two successive periods of time were equal [Locke] |
| 22882 | We use calendars for the order of events, and clocks for their passing [Bardon] |