O’Malley’s team also found that a 12-hour clock, distinct from the 24-hour circadian clock, drives this morning-evening rhythm in gene expression. The clock’s origin, the scientists suggest, may be ...

AM (Ante Meridiem) means before noon; PM (Post Meridiem) means after noon. Learn the Latin origins, history of 12 vs 24-hour ...

An analogue clock, a clock with hands, shows the numbers 1 through to 12. It is a 12-hour clock. The first 12 hours of the day, from midnight to midday, are called am. The next 12 hours ...

Scientists have identified the cells behind the bioclocks keeping time with tides in tiny marine organisms. The biological ...

The breadboard clock may not be the prettiest thing, or a textbook example of how to prototype circuits, but that was fixed with [Easton]’s friend’s PCB layout of a 12-hour clock.