Had this reflection that 144hz screens where the only type of screen I knew, that was not a multiple of 60. 60 Hz - 120hz - 240hz - 360hz

And in the middle 144hz Is there a reason why all follow this 60 rule, and if so, why is 144hz here

  • Overzeetop
    2•1 year ago

    That’s probably just fluctuations in the line frequency and the method for keeping time varying between the two (one might use a crystal that drifts). Being on the “wrong” frequency will have it shift by hours every day. I had a (US/60Hz origin) microwave in my apartment in Bonaire (50Hz) last year that never seemed to have the right time, and when I did the math I realized it was the frequency - it was behind by ~4 extra hours every day (50/60 x 24 hours).

    • SanguinePar
      2•1 year ago

      Oh ok, it’s usually a few minutes over the course of a week or so, so I guess it’s not that! :-)

      • Overzeetop
        2•1 year ago

        Yeah, that’s just a shitty (or out of spec) time base. My Seiko watch gains 1-2 minutes a day, but it’s completely mechanical so it depends on temperature and winding/mechanism tension for accuracy. There are electronic timing circuits which are resistance and capacity based, and as the resistance and capacitance of the system drift (time/age and temperature) they also drift. A crystal, made to vibrate at high frequency (piezoelectrically, iirc), will provide a much more stable time base and be accurate to seconds over many days’ time.

        Interesting aside - time keeping is how ships at sea used to determine where they were in the ocean. Latitude can be found from the stars, but longitude can’t so it needs a time reference standard. The book, Longitude tells the story of the search and the competing methods for determining location prior to the invention of crystal/electronic time bases and modern GPS. I won’t say that the storytelling is particularly gripping, but the actual path to discovery is fascinating.