Just that. I don’t understand how computers interface with a quartz crystal and the quartz crystal stores data. How does that work?
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While some companies are working on crystal-based data storage, I get the sense this isn’t really what you’re talking about.
Some crystals exhibit a property called *piezoelectricity*: they produce a voltage when you bend them, and if you apply a voltage to them, they bend slightly. By placing the crystal in the path of a low-voltage current, you can cause it to bend away from that current. The flow of electricity stops, the crystal bends back, but now it’s in the current again, so it flows through the crystal again, and the cycle continues.
There are other materials that can do this. Quartz wasn’t the first one found. But different materials and shapes will vibrate at different frequencies when you do this, and what makes quartz special is that if you shape the crystal right, you can get it to vibrate at (almost) exactly 32,768 times per second.
That number matters because it’s a power of 2. You can feed these pulses into a special circuit called a flip-flop that just turns on or off when it gets a pulse. So because it turns on or off at each pulse, it turns on half as many times a second as the pulses come. If you feed *that* back into another flip-flop, it turns on half as mant times a second as the last flip-flop did. Keep this going for 15 flip-flops (a flip-flop is simple enough to make that a bank of 15 of them is easy to put on a chip), and the very last one will pulse (almost) exactly once per second. This, then, becomes our clock. The crystal doesn’t store information: it *generates* information, and the rest of the circuit just counts the pulses it generates.
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