How an Atomic Clock Really Works: Inside the HP 5061A Cesium Clock
Why Hacker News recommends it
HN calls it one of the best explanations of how atomic clocks actually work.
What it is
CuriousMarc powers up a vintage HP 5061A cesium beam clock and explains both the quantum principle and the HP implementation in detail. It is part of a longer atomic clock series.
Recommended by 4 HN commenters across 4 different months, 2020 to 2026.
What Hacker News said
Strong rec somat · 2022-10 · on “Time is an illusion, Unix time doubly so”
CuriousMarc has an excellent episode on an atomic clock. [this video] I like to pretend I can fix computers, this guy can actually fix computers, which is probably why I find his show so fascinating.
Strong rec alnwlsn · 2026-08 · on “Atomic Clocks”
If you want to see how an actual application of this works, I've yet to see a description better than in CuriousMarc's HP 5061A series: [this video]
Recommends kens · 2020-03 · on “Living Without Atomic Clocks (2016)”
CuriousMarc made a video last week where he uses a vintage HP 5061A atomic clock and explains how it works. It's interesting to see that atomic clocks aren't just some giant laboratory thing, but a product you could buy, even in the 1960s. [this video]
Recommends puzzledobserver · 2022-12 · on “The state of the art in amateur timekeeping (2003) [pdf]”
CuriousMarc uploaded a video to Youtube showing the startup procedure for an HP 5061A cesium clock [0]. They switch on the clock and compare it to a GPS reference. Seeing the abstract description realized in concrete terms through hot cesium tubes, phase locked loops, and Lissajous curves was really fascinating. [0] [this video]