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There is an actual atomic clock watch on the market that is a little bit smaller: https://www.hodinkee.com/articles/introducing-the-bathys-cesium-133-atomic-cl
by deanmen 6y ago
There is an actual atomic clock watch on the market that is a little bit smaller:
https://www.hodinkee.com/articles/introducing-the-bathys-cesium-133-atomic-clock-watch https://www.hodinkee.com/articles/introducing-the-bathys-ces...
- mikestew 6y agoNote that bathyshawaii.com is likely no longer owned by the maker, and it most certainly is NSFW (oh, keep scrolling).
- Teknoman117 6y agoThese days it's not as complicated. Microchip has a line of "chip scale" atomic clock modules you could use to make one. Not sure what the pricing is. https://www.microsemi.com/product-directory/clocks-frequency-references/3824-chip-scale-atomic-clock-csac#overview https://www.microsemi.com/product-directory/clocks-frequency...
- sjruckle 6y agoOnly $5,100.20 from Mouser https://www.mouser.com/ProductDetail/Microchip-Technology/090-03240-001/?qs=w%2Fv1CP2dgqpPJJa0jwVC6w%3D%3D https://www.mouser.com/ProductDetail/Microchip-Technology/09...
- sosuke 6y agoIs that the same one as this is using? https://www.hodinkee.com/articles/richard-hoptroffs-atomic-watch-prototype-combines https://www.hodinkee.com/articles/richard-hoptroffs-atomic-w...
- reportingsjr 6y agoIndeed it is!
- GekkePrutser 6y agoI wonder if it's safe to wear a radioactive source on the wrist like that. Or is it not strong enough to matter?
- CamperBob2 6y agoCs 133 isn't radioactive. Tritium is, but at least until recently, it was still commonly used in watches for illumination. Low-level beta source, expensive but not especially hazardous.
- willis936 6y ago>at least until recently Has something changed? I know tritium sources are on the decline, but it always tickled my mind that radioactive lume was available to consumers for reasonable prices.
- CamperBob2 6y agoHaven't heard of it being used recently, except perhaps in gunsights, but a quick Google search brings up quite a few tritium-illuminated watches at moderate prices. I would've guessed that button-activated LED backlighting would have replaced it by now. Edit: interestingly, Wikipedia says that radium was still used in watches until 1970.
- tvb 6y agoCesium atomic clocks are not radioactive, nor are they based on radioactive decay. The isotope used for cesium beam atomic clocks is natural and stable Cs-133. The clock is based on an ultra-precise energy transition near 9.192 GHz. You may be thinking of the nasty radioactive isotope Cs-137, which is unnatural and often a byproduct of nuclear tests or accidents. It's not unlike Carbon or Potassium; Carbon 12 is the safe stuff, the rarer Carbon 14 is radioactive. Potassium 39 is the safe one and rare Potassium 40 is radioactive. Which is why bananas are slightly radioactive: https://en.wikipedia.org/wiki/Banana_equivalent_dose https://en.wikipedia.org/wiki/Banana_equivalent_dose You can make a cesium clock radioactive by placing a banana on top of it. See page 1, 36, 37 of: http://leapsecond.com/ptti2020/2020-PTTI-tvb-Atomic-Timekeeping-Hobby.pdf http://leapsecond.com/ptti2020/2020-PTTI-tvb-Atomic-Timekeep...
- hengheng 6y agoIt draws quite a lot of power. From what I remember, the lipo battery required for 16hrs w/ no display would be the same size as the already chunky module itself, requiring wristband integration. Better to have a quartz oven and fire up the CSAC only once per hour as a reference, still yielding one factor of 10 in precision. All in all it's better suited for a nice pocket watch with a 10MHz out connector. Any takers at 15k$+?
- Teknoman117 6y agoHah. Admittedly I didn't look up the power consumption. I came across these modules a few years ago randomly and seeing this article reminded me of them. I wasn't seriously suggesting it's a practical answer by any means =)