Talk:Metronome (public artwork)

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Contents 1 Atomic Time ??? 2 Photo 3 Accuracy of the clock 4 Clock Example in Article

[edit] Atomic Time ???

Can anyone confirm if the clock is linked to an atomic time server? This clock is cited as an example of an Atomic Clock on International Atomic Time but the artist's fact sheet gives no mention of this.

The only mention I can see is in a press release dated 21-Oct-1999 which states:

...indicating with atomic precision the time since midnight and counting down in hours, minutes, seconds until the midnight to come.

Blckdmnd99 13:30, 25 March 2007 (UTC)

Looks like there is at least one source to suggest the Atomic Clock link. Talk:International_Atomic_Time#Union_Square_NYC

Blckdmnd99 02:52, 27 March 2007 (UTC)

[edit] Photo

In addition to the photo currently in the article (Image:Metronome.jpg) there's another on Wikipedia (Image:UnionSquareAtomicClock.JPG) which gives a better view of the time display. --Mathew5000 06:47, 28 March 2007 (UTC)

[edit] Accuracy of the clock

This page from Alcorn McBride (which I think designed one of the electronic components of Metronome) says that Metronome is "the most accurate clock in New York City". But is that true? That web page states:

The V4+ is also responsible for synchronizing the timing of the subsystems. It receives its timing reference from the atomic clock at the US Navel [sic] Observatory in Washington DC. The V4+ then locks the entire system to SMPTE Time Code.

So if it gets a timing reference from the USNO, why would it be any more accurate than various other clocks in the city that also get a time reference from a reliable source? For example, see the correction appended to the end of this New York Times article about the new timekeeping system at Grand Central Terminal. --Mathew5000 06:58, 28 March 2007 (UTC)

Actually thinking about this a little more, I bet that the Metronome just gets the time from a GPS receiver. I believe that would be much more accurate than getting the time from a USNO Internet time server. See time dissemination. Obviously time received by GPS will be even more accurate if you have a fixed antenna and you know its exact position to within a centimetre or two. See this page from NIST, which says, "With a well-designed receiver system the user can obtain the time to better than 100 ns in a few minutes, and to about +/- 10 ns with a 24 hour average (and a good local clock)". Still, I strongly suspect that there are scientific laboratories in New York City that have more accurate clocks than the Metronome. --Mathew5000 07:44, 28 March 2007 (UTC)

[edit] Clock Example in Article

The time example in the article should be correct. Feel free to discuss here if anyone has a concern.

...if the clock reads 0704369X1235516 it means that it is 7:04 A.M and 36.9 seconds. (7 hours and 4 minutes since midnight) and that there are 16 hours, 55 minutes and 23.1 seconds remaining until midnight.

The clock takes the format:

HhMmSsT where Hh is Hours, Mm is minutes, Ss is seconds and T is tenths of seconds. The second half of the time is partially in reverse and counts down to midnight. By partially reversed, consider the following example.

If there is 16 hrs, 55min, and 23.1s remaining until midnight the clock lists this as 1 23 55 16 = 1235516 instead of 1325561. hope that makes some sense.

-DjD- 19:29, 5 July 2007 (UTC)