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The file was not saved. to make our clock so to make a nuclear clock we need light with a frequency that’s millions of times higher than what we use for atomic clocks and that kind of light just doesn’t occur naturally so scientists are still trying to figure out how to make a nuclear clock work
Thanks to @glenoud for supporting this @scishow video, you can get a $100, sixty-day credit on a new Lenovo account at lenovo.com/scishow. What is the best way to measure the passage of time for me? I got the old one Mississippi, two Mississippi trick that might help you out in a pinch, but there’s a lot of science and technology out there that needs way more accurate time keeping. These days, the best atomic clocks can tick so precisely, you would have to wait longer than the age of the universe for them to be off by one second. But some scientists are on the hunt for an even more accurate clock and they have proposed a literal nuclear option, a clock the size not just of an atom, but of an atom’s nucleus.
To make any clock, you need something that goes back and forth repeatedly at a fixed rate, that’s called an oscillator and it has a frequency, how many times it oscillates over some specified length of time. The most accurate and reliable oscillators out there are light waves, which are made of electric and magnetic fields that wobble at fixed frequencies.
But how do light waves and atoms come together to make an atomic clock? Well, we’re gonna have to get a bit quantum mechanical. The atoms are made of a nucleus surrounded by a swarm of electrons and those electrons can only exist where they have specific fixed energies. Metaphorically, you can picture these energy levels as rungs on a subatomic-sized ladder. And if you want an electron to climb up or down that ladder, it has to either gain or lose the exact amount of energy that will get it to another run.
Now electrons are fond of getting that energy by either absorbing or emitting light with the appropriate frequency, because according to Quantum Mechanics, the energy and frequency of light are directly related. The lower the energy, the lower the frequency and vice versa. So to make an atomic clock, scientists take a bunch of identical atoms like cesium-133 and hit them with a laser. That laser light has a frequency and therefore an energy and that’s as close as possible to the energy needed to bump just one of each atom’s electrons up to another run. Any electrons that do get a boost will eventually shed their excess energy and drop to their original rung and that means that they will emit light on their way down again. That light oscillates, or metaphorically it ticks, at a precise frequency and scientists count those incredibly consistent ticks to mark the passage of time.
With decades of laser science research behind them, atomic clocks are simple enough that we can shoot them into space and they’ll still be accurate down to the nanosecond. But we can do even better because atomic energy levels aren’t the only game in town. On an atom’s nucleus has its own even smaller subatomic ladder and just like electrons, a nucleus can jump from one of its proverbial rungs to another if it absorbs or releases just the right amount of energy. We’re keeping track of time, a nuclear clock can offer some advantages over the traditional atomic ones. While an electron’s ladder has rungs at very specific energy levels, those levels aren’t always constant. The position of the rungs can shift by teeny tiny amounts, if say there’s a slight shift in some external electric or magnetic field. And if your clock is the size of a single atom, teeny tiny shifts are a big deal and can throw off your time keeping ability. But nuclear energy levels are less affected by changes going on around them because the protons and neutrons inside an atom’s nucleus are so tightly bound together. These super strong bonds can help a nuclear clock tick more steadily than an atomic clock.
But there’s a catch. It also means the gaps between the energy levels, the distance between the rungs on the ladder, are on a completely different scale. Typically we’re looking at energies that are millions of times greater than what electrons are dealing with. And remember, the amount of energy needed to jump between rungs relates to the frequency of the light we need to make our clock. So to make a nuclear clock, we need light with a frequency that’s millions of times higher than what we use for atomic clocks and that kind of light just doesn’t occur naturally. So scientists are still trying to figure out how to make a nuclear clock work.