465K views · Mar 20, 2020 · 25:10 · 4 HN recommenders · 4 mentions · discussed 2020–2026
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.
Why Hacker News points people here: HN calls it one of the best explanations of how atomic clocks actually work.
“I've yet to see a description better than in CuriousMarc's HP 5061A series”HN comment, 2026
“CuriousMarc has an excellent episode on an atomic clock.”
Excellent atomic clock episode
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.
“I've yet to see a description better than in CuriousMarc's HP 5061A series”
Best description of how atomic clocks work
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
“It's interesting to see that atomic clocks aren't just some giant laboratory thing”
Explains a vintage 1960s HP cesium atomic clock
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
“was really fascinating”
Startup of cesium clock compared to GPS reference
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
