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Comment by TwoBit

7 years ago

What is it about Helium that breaks the device? Is the device intended to contain a vacuum?

The microscopic oscillating part in the clock needs a vacuum. Having air around would dampen the vibrations too quickly because the mass is tiny, and the timing would vary with air pressure or humidity.

It sounds like microelectromechanical devices (like the quartz oscillators that keep time in electronics) are so small, and built to such fine tolerances, that helium atoms can literally, physically jam them like sand in a gearbox. That's what the article seems to be saying, anyway.

I guess they're fine under normal conditions because typical atmospheric molecules are actually too big to get inside? I'm not clear why the particular clock that Apple used is susceptible but other ones aren't. I guess they're sealed better.

  • Other devices use a solid-state quartz oscillator. This is a hollow mechanical frequency generator.

TL;DR: it breaks the oscillator that keeps time on the device. This breaks the clock and eventually has a cascading effect on the system.

The article is pretty straightforward and engaging; it's worth a read!

  • Oh wow, so the clock is unnecessarily coupled to the other systems?

    • Tons of events are tied to the real-time clock. For example if the interface code wants to know how fast you're dragging your finger across the screen, it divides the distance between digitizer samples by the elapsed time. Or to know if a "tap" is a "long press", it has to know how long it was. All kinds of stuff depends on that clock.

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Helium molecules are small enough to cause issues with iOS devices' internal clock.