Of course, everybody knows what an alarm clock is and what it is used for. However, most of us don’t know who invented it and how.
It was the ancient Greeks who first came up with the alarm clock. Before, people would get up with the sun but that was not helpful when you needed to get up before sunrise or at specific times during the day or night.
The ancient Greeks were the ones to invent the alarm clock. It is attributed to Ctesbius, an inventor and mathematician who had invented the water clock (Clepsydra), which consisted of a recipient filled with water but with a hole in it’s bottom through which water poured continuously, thus measuring the time it took for the recipient to loose all of its water.
In fact, the first alarm clock was pretty simple. An empty recipient was placed below the Clepsydra so it would receive its water and fill. This recipient would also have a rod placed vertically with a cork on its lower end. As the recipient filled, the cork will float upwards and the rod would be pushed up. A bell was placed above the higher end of such rod, in a way it would fall as soon as the rod went up enough to hit it. So it was just a matter of (adjustable) time until the bell would fall and make its unmistakable sound.
It’s a simple method, but it is interesting to think how they came up with such an idea.