The time has come for us to take a deep dive into the fascinating world of atomic clocks. NASA uses its very own Deep Space Atomic Clock for space navigation. And if one thing is true about atomic clocks it is that they are very accurate. How accurate? Well, about being off by just one second every 10 million years! But what exactly is an atomic clock and how does it work?
First off, let’s talk about the heart of an atomic clock – the atom. And not just any atom, mind you, but the cesium atom to be precise. You see, the cesium-133 isotope is the MVP of the atomic clock world, and its electrons are arranged in a way that makes it particularly suitable for timekeeping. But why use cesium-133, you ask?
Cesium-133’s resonant frequency, or the frequency of electromagnetic radiation emitted when its electrons drop back down to their original energy level, is precisely 9,192,631,770 Hertz. And that means that an atomic clock can measure time with a precision of one second in many millions of years, making it the most accurate timekeeper in the world.
Now, how does an atomic clock actually measure time? It’s simple, really. The cesium atom is first excited by a radio frequency, causing its electrons to jump to another energy level. And then, after a brief period of time, the electrons drop back down to their original energy level and emit a specific frequency of electromagnetic radiation in the process. This is called the resonant frequency of the atom, which the atomic clock uses as its resonator, and it’s what the clock uses to keep time. The resonant frequency of atoms also happens to be super consistent, making them ideal to keep time as accurately as possible.
By counting the number of cycles of this frequency over a period of time, the clock can keep an extremely accurate record of the passage of time. It’s like counting the number of breaths you take in a minute – except much, much more precise.
Now, we all know that mechanical clocks can be affected by changes in temperature, air pressure, and other environmental factors. Yes, even the above-pictured million dollar Patek Philippe can’t get anywhere near the accuracy of an atomic clock. Atomic clocks are extremely stable and accurate. In fact, atomic clocks are so precise that they’re used in GPS navigation systems, global communications networks, and even the synchronization of atomic bombs. Talk about a timekeeper with a bang.
In addition to cesium atomic clocks, there are other types of atomic clocks too, including hydrogen maser clocks and rubidium atomic clocks. But no matter which type of atomic clock you choose, you can be sure that it will keep time with the accuracy and precision that only an atom can provide.
That Will Make You Re-Think Timekeeping