Human beings have thought about time from the very beginning of our existence. Since we first understood time, we’ve been trying to build accurate tools to measure it. In this list, we’ll focus on the most common tool that we use to measure time: the clock. Clocks come in many forms: physiological “clocks” within the human body, mechanical clocks, electronic/digital clocks, and even clocks that use water to keep time.

What this list reveals is that man has been fascinated with time and timekeeping—hence, clocks—for a very long time. It also shows that the clocks built a very long time ago were surprisingly advanced and unexpectedly accurate. Human beings have always had an insatiable thirst for continuous improvement, so this list also takes a peek at the probable future of advanced clocks: clocks powered by the highly precise events that occur within atoms. Please synchronize the time on your watches, and let’s dive into the list!

Related: 10 Inventive Ways the World Is Reimagining Defunct Phone Booths

10 Using the Blockchain as a Timekeeper

When you hear the term “blockchain,” you probably think of people sending and receiving digital currencies. But D4D, a Swiss tech company, has a new vision: a blockchain-based clock. In 2024, they patented Clockchain, a decentralized timekeeping system that reimagines the concept of a clock. Instead of relying on traditional systems that can drift or be altered, Clockchain offers a secure, unchangeable source of time.

For industries like banking and healthcare, where precision is critical, Clockchain eliminates the risks of inaccurate or tampered timestamps. Its design ensures that every second is accurately logged. This could redefine how we handle everything from transactions to patient data.

As Web 3.0 (a decentralized web) evolves, Clockchain, if widely adopted, could reshape the future of digital timekeeping. Software developers could rely on its tamper-proof, reliable foundation to revolutionize how time is recorded across digital platforms. In many ways, Clockchain might end up being a modern-day reinvention of an age-old concept.^[1]

9 The Tidbyt: A Retro Pixel Art Clock That’s Pure Fun

The Tidbyt is a very modern clock that packs a lot of unusual features into a small package. It has a sleek walnut frame and a nostalgic pixelated display that blends retro charm with modern functionality. It can do a lot more than just tell time. For example, it can show a range of useful information like bus schedules, sports scores, and even interesting animations. It has over 700 customizable apps.

Unlike many modern “toys,” the Tidbyt is a simple device. It’s not a smart assistant: there are no microphones or cameras, just a customizable display that adds a touch of fun to the device. A final nice touch is that it can display low-resolution art for its owner.

At $200, the Tidbyt isn’t cheap, but its charm has drawn a loyal following. Tidbyt’s open platform allows for endless possibilities, and this open architecture can make it an interesting item to own for many years.^[2]

8 The Clepsydra of Karnak: Egypt’s Ancient Water Clock

The Clepsydra of Karnak, dating back to 1391–1353 BC, is one of humanity’s earliest known water clocks. The alabaster vessel, used in the Temple of Amen-Re, offered a way to track time without relying on the sun or stars. Its design featured 12 carved columns representing the hours of the night, and it was considered a breakthrough in timekeeping technology during its day.

Water would slowly flow through a small hole, and as the water level dropped, time was measured accurately. This was especially useful during cloudy or nighttime periods when traditional methods were unreliable. The Clepsydra’s precision made it highly valuable for priests conducting rituals or for daily activities.

Beyond its practicality, the Clepsydra was also a spiritual object. Decorated with symbols of constellations and gods, it reflected the Egyptians’ belief that timekeeping was connected to divine rituals. In Egyptian culture, the Clepsydra wasn’t just a tool; it was a sacred artifact.^[3]

7 The Rediscovery of Cartier’s Magnificent Water Clock

In 2024, Cartier’s long-lost “Pendule Magnétique,” or water clock, resurfaced at a Phillips auction. This masterpiece, created in 1929, was the result of Cartier’s advanced craftsmanship, and the clock included a rare 17th-century jade basin. The basin contains a floating carp that indicates the time, driven by a magnetic movement beneath the surface.

This clock is notable because it combines advanced mechanics with beautiful aesthetics. Only three of these water clocks were ever made by Cartier; it’s a very rare and historically significant timepiece.

After being hidden in a private collection for decades, the clock’s Art Deco design and Chinese motifs excited potential collectors when its existence was revealed to the general public. The clock’s uniqueness means that it could command a high price when auctioned off.^[4]

6 The Beetle with a 48-Hour Biological Clock

The large black chafer beetle, Holotrichia parallela, operates on a 48-hour biological clock, an unusual pattern for most living organisms. Female beetles emerge from the soil every other night to release pheromones, attracting potential mates. This circabidian rhythm controls the females’ reproductive behavior, making their emergence a predictable event in an otherwise mysterious cycle.

Male beetles are equally synchronized with this 48-hour clock, and their ability to detect the females’ pheromones is heightened during this period. Researchers have identified a specific gene, HparOR14, responsible for this sensory regulation, marking the first time such a pheromone receptor has been discovered in a beetle species.

Despite these findings, scientists are still puzzled about the environmental triggers that govern this unusual cycle. Unlike the common 24-hour circadian rhythms tied to day and night, the 48-hour rhythm of these beetles remains unexplained. Future research might help us uncover why the black chafer beetle developed such a unique clock.^[5]

5 Tuning Medicine to Your Body’s Internal Clock

Your body’s internal clock, known as the circadian rhythm, controls sleep and can have a significant impact on how effective medications are when you take them. Chronotherapy is a treatment approach that aligns medications with your body’s natural clock. Research shows that certain drugs, like aspirin or cancer treatments, are more effective when taken at specific times of the day, synchronized with your body’s internal rhythms.

How does it work? Your hormones, temperature, and immune system all fluctuate throughout the day. Chronotherapy taps into these natural changes, timing treatments to when your body is most receptive. It’s a powerful idea: fighting diseases like cancer by simply adjusting the timing of medication.

Despite its promise, chronotherapy is still underused. One challenge is identifying reliable biomarkers like blood pressure or body temperature to determine the best time for treatments. While it’s a timely idea, literally, more research is needed to unlock chronotherapy’s full potential.^[6]

4 Al-Jazari’s Elephant Clock

Al-Jazari’s Elephant Clock is an 800-year-old clock that fuses influences from many different cultures. Created in the 12th century, this clock uses water and gears to track time with impressive accuracy for when it was built. Each part of the design represents a different culture: the elephant symbolizes India and Africa, the dragon comes from China, and the phoenix from Egypt. Greek and Persian influences appear as well, all topped by a turban to mark its Islamic origin.

The clock, on display at the King Salman Science Oasis in Riyadh, Saudi Arabia, is one example of the innovation that took place during the Islamic golden age. Al-Jazari built a cultural bridge that showed how different cultures influence each other.

Visitors who view the Elephant Clock today are reminded how important science and creativity were, even eight centuries ago. The clock is also a reminder of how important technology was in ancient Islamic civilizations.^[7]

3 Your Blood’s Internal Clock

What if your blood could tell you how fast you’re aging? Scientists have created a “proteomic aging clock” that can estimate your biological age by analyzing specific proteins in your plasma. Instead of being a measure of how many years you’ve lived, it’s really a measure of how well your body’s holding up with the passage of time.

The “blood clock” has been tested in large populations across the UK, China, and Finland, and the results are stunningly accurate. It predicts risks for diseases like diabetes and heart disease, giving doctors a powerful tool for early prevention.

Basically, this clock measures how well you’re aging from the inside out. With further research, it could even help reduce the risk of premature death. The clock ticks: it never stops, and it gives a very accurate and timely reflection of how healthy you really are.^[8]

2 Atomic Clocks and Dark Matter Detection

Scientists are actively developing atomic clocks so precise that they could help to solve one of the universe’s biggest mysteries: Where’s all the dark matter? While dark matter is believed to make up most of the universe, it has remained undetectable for decades. Researchers at NIST have made a breakthrough with a new atomic clock that measures tiny shifts in atoms’ energy. This clock could act as a sensor for subtle cosmic signals, including those from dark matter.

These atomic clocks are so sensitive that they can also track gravitational shifts on Earth with extreme precision. But the real excitement comes from the potential to detect dark matter, particles that have so far escaped direct observation.

By observing slight changes in space-time, scientists believe these clocks could eventually provide evidence of dark matter’s existence. The hope is that these advanced atomic clocks will help us to unlock some of the secrets that the universe is hiding from us.^[9]

1 Superradiant Atomic Clocks

Superradiance is changing how atomic clocks work, offering new levels of precision. Traditional atomic clocks use lasers to control atoms, but this can cause slight disruptions. At the Niels Bohr Institute, scientists have developed superradiant clocks, which use atoms that naturally emit light in sync. By avoiding laser interference, these clocks can operate without the usual heat issues, making them far more accurate.

What’s exciting about this technology is its potential beyond just keeping time. These clocks could be used in various fields, like detecting minor gravitational shifts that occur before earthquakes, offering a unique way to predict natural disasters.

With further research, superradiant atomic clocks could radically upgrade how we measure time. This could build on our understanding of our world and create a positive feedback loop that continuously improves society with new technological breakthroughs.^[10]