The document discusses the history and origins of clocks. It notes that early civilizations used sundials and water clocks to tell time before mechanical clocks were invented. The earliest known clock was a sundial invented in Egypt around 4000 years ago. Over time, more accurate mechanical clocks were developed to divide the day into smaller fractions as the need to measure time more precisely increased. However, the clock has no single inventor as it evolved gradually over many centuries through the work of various civilizations.