EEVblog #646 - Gravity Detection Using A Frequency Counter!
Why Hacker News recommends it
HN links it as a hands-on demonstration that oscillator frequency depends on orientation relative to gravity.
What it is
Dave Jones of EEVblog demonstrates that a frequency counter can detect gravity through the 2g tipover effect on quartz crystal oscillators. He shows the reading shift as the instrument's orientation changes.
Recommended by 0 HN commenters across 0 different months, 2014 to 2023.
What Hacker News said
Cites snogglethorpe · 2014-11 · on “A clock that can detect tiny shifts in the flow of time itself”
> Yeah, they're not sensitive to magnetic fields. But they do drift with temperature Also, gravity: [this video]
Cites comboy · 2015-05 · on “1 second per second is harder than it sounds (2014)”
My bad, I was before my coffee. One additional thing that wasn't yet mentioned is that freqency depends also on gravitation, so orientation of your motherboard could matter (for the curious - [this video] ). I'm not really sure it's big enough to matter though.
Cites SamReidHughes · 2019-01 · on “Masahiro Kikuno, Japanese Independent Watchmaker (2017)”
The Zenith Defy Lab watch has accuracy of -0.5/+0.5 seconds per day, which matches and/or beats quartz watches (that aren't thermocompensated). Rolexes, which have a classical movement design, are pretty close, promising -2/+2 spd. Quartz watches' accuracy also varies depending on orientation, for what it's worth. (It has an effect on the order of 1-2 seconds per year.) Related EEVBlog link: [this video]
Cites gugagore · 2019-02 · on “TI Claims Breakthrough in BAW On-Die-Oscillators”
Maybe if you can show me that if you flick an RC oscillator you can detect it, then I'll believe it's a silly distinction. Or if RC oscillators can detect gravity: [this video] I'm also curious what it would mean to you for two things to be doing "fundamentally different" things. Do you believe in the difference between a mechanical oscillator and an electrical oscillator? Mechanical oscillators like a spring/mass exchange energy between kinetic and electrical energy (a moving mass and a strained material). An RC oscillator exchanges energy between elements that store energy in an electric field and a magnetic field. That feels fundamentally different even in a four-fundamental-forces kind of man
Cites formerly_proven · 2023-11 · on “Why the Position of a Watch Influences Accuracy (2020)”
> Typical crystal acceleration sensitivities will range from about 1 x 10-10 per g for specially constructed precision SC-cut and AT-cut resonators to the order of 10-7 per g for tuning fork resonators. [LINK] Demonstration: [this video]