Long before clocks and watches were invented, people were content telling the time by using things like the sun and the moon. They woke up when the sun was up, and they’d go to sleep roughly around the time the sun set. This kind of timekeeping was good enough for most people, but as civilizations advanced, the need for more accurate time measurements grew.
People used all kinds of methods to start telling time. For instance, people used sandglasses to tell specific amounts of time, there were timekeeping devices made with water, and some cultures used incense to tell time. Eventually, it became the norm to use oscillating mechanisms to start telling time. These devices would have some kind of pendulum that would swing back and forth to a specific rhythm, much like grandfather clocks that still exist today.
Eventually, people began to switch from mechanical oscillating mechanisms to electronic ones. This provided even greater accuracy and control, leading to better clocks and more precise timekeeping.
But things changed during the 1940s when quartz quickly became the basis for all precise measurements of time and frequency. How exactly did this happen and why is quartz considered such a great material for the job?
Understanding how clocks work
To begin, it’s important to understand how clocks actually work. This will set the basis for the rest of the article and also offer some foundational knowledge to help you better understand later concepts.
The manual human clock
Let’s start with the most simple clock that you could create yourself: the speaking clock. Have you ever counted seconds by saying “one Mississippi, two Mississippi” and so on? This is a pretty common way to count seconds without relying on any kind of clock or device.
It works to some extent because the time it takes for the average person to say Mississippi is roughly equivalent to a second. If you said one Mississippi all the way to sixty Mississippi, then it’d take close to a real minute.
But what if we tried to use this as a practical timekeeping method? It wouldn’t work very well because you’d be constantly counting it yourself, leaving no room to do other things! This forms the foundation of why clocks exist in the first place–because keeping time by ourselves is a lot of effort, but can be handled by devices instead.
Many early clocks used things like water, incense, or even sand to tell how much time had passed. However, it wasn’t until the use of pendulums that we started to really advance technology in this field.
The Italian physicist Galileo Galilei discovered that pendulums of a certain length would always take the same time to swing back and forth regardless of how heavy it was or how wide the swing was. He discovered this after watching a giant lamp swinging from a chain in the Pisa Cathedral in Italy, noticing that he could synchronize the swinging with his own pulse. This discovery helped with the invention of many early pendulum clocks.
In a clock, the pendulum is used to regulate the speed at which the gears inside the clock turn. If we compare this to our manual human clock, then it could be said that each swing of the pendulum is essentially the same as us counting a Mississippi.
But if you’ve ever swung something similar to a pendulum, then you’ll probably know that the swinging doesn’t last forever. If you were to use a set of swings, then the force you exert will gradually come to a halt due to factors like gravity, air resistance, and friction. The energy would eventually run out, and you’d have to “swing” the pendulum again.
Pendulum clocks solved this problem by using springs. These clocks would require people to manually wind the springs inside of the clock to store potential energy. So despite the advances in timekeeping, pendulum clocks still required some level of manual control or else they’d stop working.
The pendulum clock mechanism was far too big to fit into a pocket watch, but a similar mechanism known as a balance wheel was invented to mimic the same concept. It’s a weighted wheel that rotates back and forth, returning to its center position with help from a spiral torsion spring. Much like the pendulum clocks of the time, it had to be manually wound in order to function correctly.
It wasn’t until 1840 that the first electric clock was invented. Instead of using a mechanical system that was powered by a spring or weight, it used an electric current to power the pendulum. This meant that there was no need to manually wind a mechanism to power the timekeeping device, making it even more convenient to use.
But while revolutionary for their time, these clocks still had a glaring issue to be solved: the pendulum itself.
The problem with pendulum clocks
Alexander Bain, the inventor of the electric clock, gave us a great solution to the inconvenience of needing to wind a clock. There would be no need to wind a clock with an electric current, meaning our clocks would run indefinitely as long as they had power. Great! However, there was still; another problem that had yet to be solved.
While the pendulum was powered by an electric current, the pendulum itself was still a mechanical device that was affected by gravity. This meant that clocks would keep time a little differently depending on where you were. Pendulum clocks would give different readings based on your altitude due to gravity.
Another problem is that pendulums could physically change due to their environment. Warm days meant that the materials could expand, creating a longer pendulum. On colder days, it could contract and affect the accuracy once again.
It wasn’t until the introduction of quartz watches that this problem would be solved for good.
How do quartz watches work?
Quartz essentially replaces the need for a pendulum or balance wheel in clocks and watches, but it’s a lot more complicated than just having something swing back and forth mechanically. It uses something called a quartz oscillator. This can be a really small device inside of a watch or clock that replaces the need for a pendulum.
Quartz oscillators are powered by electronic circles. This means that a battery is required in order to power a quartz watch or clock. However, it doesn’t take much electricity, meaning a single battery could power a timekeeping device for a very long time.
As electricity is sent to the quartz oscillator, it oscillates (or vibrates) at a precise frequency of 32,768 times per second. An electronic circuit counts these thousands of oscillations, and then generates an electric pulse once it counts up to 32,768. These pulses can then be used to power a small electric motor to turn the gears of a watch or clock, or they can be read by another electronic circuit, such as in a digital clock.
In short, the quartz oscillator is there as a replacement for the pendulum, serving the exact same purpose. At the beginning of this piece, we mentioned that you could create a manual human clock by just counting Mississippi. We then replaced that manual counting with a pendulum, creating a more convenient timekeeping device that didn’t require us to manually count. In the present day, we’ve replaced the majority of these pendulum and balance wheel devices with an inexpensive quartz oscillator that is powered by a small battery.
The parts of a quartz watch
The majority of all quartz watches follow the same structure.
First, a battery is required to power the entire device. A small microchip is used to oscillate the quartz crystal exactly 32,768 times a second. This microchip is coincidentally cut in a precise way that looks like a tuning fork. The same microchip is used to detect the number of times the crystal oscillates. Once it has counted 32,768, it will then send an electric pulse to another part of the watch.
Here is where things can diverge. In a traditional timepiece, this pulse would be sent to an electric motor which turns the gears of a clock or watch. These gears are essentially the same as the gears in an older timekeeping device–this part hasn’t changed. These movements will then turn the hands of the clock or watch, and the whole process repeats for every second.
But in a digital watch, this electric pulse can be detected by another circuit board and then converted into a digital signal. This usually just progresses the time by a second, and then it can be relayed on a display to show the updated time.
Types of watch movements
There are currently three different types of watch movements that are in use today.
Mechanical watch movements
Most early watches were powered by mechanical movements. These are the watches that used balance wheels which mimicked pendulum clocks. Much like those larger clocks, these would need to be manually wound in order to function. The momentum stored in the winding mechanism would translate into kinetic energy that would move the balance wheel, thus powering the gears and progressing the hands.
However, mechanical watch movements have the same issue that pendulum clocks had–you had to constantly wind them. While modern advancements have made it possible to wind these watches less frequently than before, it can still be a hassle to do so on a regular basis.
Automatic watch movements
To solve the inconvenience of mechanical watch movements, automated movements were introduced. These harnessed energy from the wearer’s own movements, storing it much like the energy in a wound spring and then using it to power the gears of the watch.
It works by using a weighted rotor mechanism that spins as you move your wrist, winding a spring that powers the gears. However, it’s still possible to manually wind a watch like this in the event that it hasn’t been used for some time, or if you don’t plan to use the watch for a while.
Automatic watch movements are also popular because of the weight of the watch. Since the device requires a lot of mechanical parts, they can be fairly heavy compared to other types of watches. This can make the watch feel more sturdy and reliable, and some people enjoy the hefty feel.
Quartz watch movements
The very first quartz watch was released by Seiko in 1969, named the Astron. It uses the exact same technology that we described in the previous section; a battery that powers a circuit that oscillates a quartz crystal.
Despite the breakthrough, quartz movements are actually fairly cheap to produce due to how common the material is. They’re also far more reliable in terms of timekeeping compared to other options at the time, especially given that they were electronically driven.
Today, quartz movements are still the most popular option for the majority of watches. However, more precise options do exist for high-end watches as well.
Benefits of quartz watch movements
Quartz watch movements are considered to be highly accurate due to the nature of the quartz material. In addition, they’re far more affordable and easier to produce than most watch movements, requiring fewer materials and components, and also being less susceptible to damage due to the lack of fewer moving parts. Since they’re powered by a battery, keeping the device functional is fairly easy and requires far less maintenance.
In short, quartz watches are robust, durable, and can last a very long time without any maintenance at all. If this is the type of watch that you’re searching for, then a quartz watch could be the ideal option for you. As long as you remember to replace the battery, keep it serviced and clean it regularly, you can expect a quartz watch to last a lifetime.