The ancient Greeks measured time in part because human beings have felt the need to track the passage of their hours and days since time immemorial, prompted certainly by the need to plant things at the appropriate time, on the appropriate day at just the right time of year.
Perhaps there has just always been in us the need to chronicle our days and record their passage for their own sake. Some historians believe that the first timekeeping devices were created through a desire to chart our lives using the principles of astrology.
Whatever first prompted us to try to record time, doing so has been a drive in human beings since the Neolithic era, according to a new book by physicist Chad Orzel called “A Brief History of Timekeeping,” published by BenBella Books in 2022.
Water clocks, sundials are first ancient timepieces
People around the world were already making valiant attempts to predict solstices and other astronomical occurrences back in the Neolithic era.
Orzel traces the evolution of recording time, from the water clocks that showed how long it took water to flow out of a container to elegant sand-filled hourglasses to the first mechanical and pendulum-driven clocks.
As can be appreciated by anyone, the attempt to conquer time by being able to quantify it appears to be a universal need.
Water clocks, along with sundials, are most likely the oldest time-measuring instruments, with the only exceptions being the tally stick, which counts days. Given their extraordinary antiquity, where and when these time pieces first existed is not known — and perhaps will remain unknowable, according to Scientific American.
The bowl-shaped outflow water clock, or clepsydra (“water thief”) is the simplest form of such clocks; they are known to have existed in Babylon and in Egypt around the 16th century BC.
The ancient Greeks — of course — were among the first to create mechanical clocks to measure time; the perfection of the clepsydra and the alarm clock created by Plato are just two such brilliant inventions.
Great philosopher Plato invents the alarm clock
Plato, the famous ancient Greek philosopher and mathematician who lived from ca. 427 BC to 347 BC, and who founded the first institution of higher education in the Western world, the Academy of Athens, was said to have been the first person to introduce the snooze alarm into human history.
In his effort to wake people up and get them to their lectures on time — at dawn — Plato designed a mechanism which can be considered the first alarm clock.
In his mechanism, water would drip from one vessel into another via a small hole, and as the second vessel filled during the night, trapped air was forced out of a side vent, making it whistle like a tea kettle when it filled up quickly.
The Water Clock, or Clepsydra, at the Amphiaereon of Oropos
Located at the Amphiareion of Oropos, a sacred site which contains the ruins of a theater, altars, a sacred spring and many other historical artifacts of immense value, this water clock — roughly contemporary with Plato’s alarm clock — is one of the most outstanding for the level of scientific expertise it represents.
The site of a holy spring where tales of heroes blended into myth, it is said that the earth once opened up and swallowed a chariot owned by Amphiaraos in that very spot. It became a site of worship and the place where athletic games took place once every five years.
A sanctuary was dedicated in the late 5th century BC there to the hero Amphiaraos, where pilgrims went to seek oracular responses to their questions as well as healing from infirmities. The cult that grew out of the site was both public and private.
On the southeast side of the streambed opposite the sacred spring there is the wonderfully well-preserved clepsydra, which incredibly still has its bronze stopper. This artifact is especially important in the study of ancient methods of timekeeping in that it is an example of an inflow water clock.
Since an inflow clock measures time by the filling of a known volume from a constant rate of inflow, it is much more accurate than an outflow water clock in measuring the gradations between full and empty.
The clepsydra at Oropos was composed of a central, square reservoir with a steep stairway on the south side to allow access to the bronze plug at the bottom of the reservoir, all of which are still extant.
An academic paper on this amazing work of human ingenuity was published in the journal Mediterranean Archaeology and Archaeometry in 2010.
Ctesibius’ water clock was most accurate timepiece in the world for 2,000 years
Ctesibius — who is known today as the father of pneumatics, or the physics of air pressure, and who is credited with the invention of the hydraulic organ, improved on the water clock so much that his version was the most accurate clock ever constructed — for more than 2,000 years — until the Dutch physicist Christiaan Huygens’ invention of the pendulum clock in 1656.
“Now what Ctesibius did was particularly cunning,” explains Marty Jopson, a model maker who created a new version of the clock invented by Ctesibius, noting that he made sure that the height of water in the initial chamber never changes.
He accomplished this by feeding water into one chamber and attaching an overflow pipe which fed into another chamber. The water in that second chamber would rise at a precise rate, allowing time to be measured accurately. This was nothing less than a stroke of genius.
But in order to have a water clock that would operate continually, without a chamber having to be emptied, something had to be altered.
“What he did was that he added a siphon to the system,” Jopson notes, adding “this may well be the very first time a siphon was fitted to a machine.” Ctesibius is therefore known as the creator of the siphon.
This allowed the clock to be emptied and refilled automatically, which was nothing short of revolutionary.
But how the Greeks measured time itself posed a problem. They divided the daylight hours into twelve — so that the hours were shorter in the winter than in the summer. That led to the need to create a clock on which they could rely for accurate timekeeping.
So Ctesibius created a waterwheel and a series of cogs that turned a cylinder which turned a tiny amount every day, tracing the hour lines on a pole, which would be nearer or father apart depending on the time of the year. This itself is a marvel of human engineering.
“Ctesibius’ water clock ran seven days a week, 365 days a year. For over two thousand years, this was the most accurate clock in the world,” Jopson says.
Ptolemy’s astrolabe measured time and the stars
An early astrolabe was invented in the Hellenistic civilization by Apollonius of Perga between 220 and 150 BC, but it was often attributed to Hipparchus. The device, a marriage of the planisphere and the dioptra, was effectively an analog calculator capable of working out several different kinds of problems in astronomy as well as the time of day or night and the seasons.
The Greek scientist Ptolemy of Alexandria, who lived from 85 to 165 AD, created an early astrolabe he called the “Planisphaerium,” which dealt with the problem of mapping figures from the celestial sphere onto a plane, by a method now known as ‘stereographic projection’, that preserves circles.
This stereographic projection later became the mathematical basis of the plane astrolabe, which developed into all later forms of the device.
Theon of Alexandria, who lived from c. 335 – c. 405, wrote a detailed treatise on the astrolabe; it is believed that Ptolemy used his astrolabe to make the astronomical observations recorded in the “Tetrabiblos.”
The “Tower of the Winds” or Horologion
The Greek astronomer Andronicus of Cyrrhus supervised the construction of the Tower of the Winds in Athens about 300 years later, in the 1st century B.C., in another example of Greek scientists who desired to quantify time.
The Tower of the Winds, or the Horologion, is an octagonal Pentelic marble clocktower in the Roman Agora in Athens that functioned as a large timepiece that was understandable and accessible to everyone.
It is considered the world’s first meteorological station. Unofficially, the monument is also called Aerides (Greek: Αέρηδες), or “Winds,” since it features a combination of sundials, a water clock, and a wind vane. It was designed by Andronicus of Cyrrhus around 50 BC, but some historians believe that it might have been constructed in the 2nd century BC, before the rest of the forum.
Chad Orzel explains to Scientific American that the advent of clocks — as seen in the many permutations of timepieces in ancient Greece — ultimately changed history in that the average person in a society could know just exactly what time it was. You didn’t have to be a wizard or astrologer or have access to a particular structure which had been created to mark the solstices to know what time it was after the invention of clocks.
In the end, it was the cumulative brilliance of all the inventions that came before it, coupled with the genius of the great mathematician Archimedes, that went into the creation of the Antikythera Mechanism, known as the World’s First Computer.
This had less to do with trying to track the events marked by time — such as Olympiads — created by humans as it was a way to celebrate creation for its own sake. As such it goes far beyond a “mere” timepiece — but it represents the fruition of the ancient Greeks’ brilliant inventions.
This incredibly intricate machine, made of bronze with mechanical movements showing the planets and stars in their different orbits around the Sun, was the ultimate representation of all that the ancient Greek thinkers valued — in that they attempted to recreate a small universe as a way to grasp its unimaginable complexity intellectually.
“The democratization of time” over the millennia
“There’s an interesting democratization of time as you go along,” Orzel states, adding “The very most ancient monuments are things such as Newgrange in Ireland. It’s this massive artificial hill with a passage through the center. Once a year sunlight reaches that central chamber, and that tells you it’s the winter solstice. This is an elite thing where only a few people have access to this information.”
However, “with the advent of water clocks, that’s something that individual people can use to time things. They’re not super accurate, but that makes it more accessible. Mechanical clocks make it even better, and then you get public clocks — clocks on church towers with bells that ring out the hours. Everybody starts to have access to time.”
Water clocks such as those created in ancient Greece went on to be used for many centuries afterward. Orzel says “There’s a famous example. There was a fire in a particular monastery, and the record says some of the brothers ran to the well, and some ran to the clock. That tells you that it was a water clock because they’re going there to fill up buckets to put the fire out.”
All of the hours counted by these timepieces add up to days, weeks and months — and how a society’s way of keeping time reveals what it values in many ways, Orzel maintains, as seen in how it compartmentalizes time relative to the seasons.
“None of the natural cycles you see are commensurate with one another. A year is not an integer number of days, and it’s not an integer number of cycles of the moon. So you have to decide what you’re prioritizing over what else. You have systems such as the Islamic calendar, which is strictly lunar. They end up with a calendar that is 12 lunar months, which is short [compared with about 365 days in a solar year], so the dates of the holidays move relative to the seasons.
“The Jewish calendar is doing complicated things because they want to keep both: they want holidays to be associated with seasons, so they have to fall in the right part of the year, but they also want them in the right phase of the moon.”
Meanwhile, he states “The Gregorian calendar sort of splits the difference: We have months whose lengths are sort of based on the moon, but we fix the months, so the solstice is always going to be June 20, 21 or 22. We give the position of the year relative to the seasons priority above everything else.”