My sister owned an atomic clock and the day she died and we came home from the hospital we saw the hands go around and around really fast for 15 minutes and then reset itself at the exact right time.
Anyone know if this is something an atomic clock can do, because otherwise we assumed it was my sister saying goodbye.?
“we saw the hands go around and around really fast for 15 minutes and then reset itself at the exact right time.”
Normal behavior. The “atomic” clocks for home use are actually radio controlled clocks...they get signals from NIST via very low frequency radio. Most of them re-calibrate once a day. I have 2 analog versions that do more or less what you described at about 1:30 am local time every day.
My Casio wristwatch does such as that, twice a year. More often if I travel and need to change the timezone offset.
First, the second hand goes to the noon position. Then the minute and hour hands move to the new position in a sweeping motion. Then the second hand moves into place. And then back to normal: tick, tick, tick ...
Of course, the hour, minute, and second hand are all just for display. The actual time is just a number it maintains internally. Every morning, the watch tunes into NIST's atomic clock radio station and sets itself to the time being broadcast, including whether DST is in effect.
So, I don't have to do anything unless I change timezones. Not bad for ~$100 in 2004. Did I mention, it's solar powered? No need to change batteries.
But I'm jealous. I've heard there is a watch that sets itself via GPS. Since it thereby knows not only the exact time but also where it is, there is no need for the wearer to fiddle with timezones. Nice.
I have both digital and analog “atomic” clocks. The analog one does what you described twice annually plus any other is time its off. A dead battery is usually cause for the other times.
That is typical of "cheap" atomic clocks (less the $100.) I own 4 of them.
Without exception they can't adjust themselves backwards. So when it resets itself daily, and it's a few seconds fast, it spins like mad until it synchronizes with the correct time the hard way.
Why that is still so, I have no idea; the oldest and the newest (spanning a 20-year period) all behave identically.
I would think that the efficient way to do that to conserve battery power, would be to just stop the clock for 4 seconds, rather than spin forward for 23 hours, 59 minutes and 56 seconds.
I suppose that would complicate the logic of the clock, and triple its cost. or something equally silly.