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Debating the Second

January 23, 2012, 12:27 pm

I thought this was an interesting discussion of leap seconds.  At its heart, the debate is about a tradeoff between hassle (a lot of programming goes into inserting a second into a day every year or so) and how close we want time to match its traditional association with astronomical observations (e.g. noon is exactly noon at Greenwich).   This is a debate that has occured at least since the imposition of time zones (mainly at the behest of railroads) which for many cities converted "sun time" to "railroad time."  Until then, every town was on a different time with noon set to local astronomic noon.  Now, only a few cities actually have noon at noon.  Of course, daylight savings time took this even further.

Tags:
Category: Science
  • DrTorch

    Daylight savings is disgusting. It is the perfect example of how a gov't program can impact every citizen, impose signficant costs, and generate absolutely no benefits. Most people don't even know the purpose or origin behind DST, and it's unclear if even the government's propaganda is accurate.

    What we do know is that it's in place (in most places) and no-one will just say, "let's end this fiasco."

    I would think that libertarians could make a lot of ground every spring by reminding people of this.

  • Mark

    But if we were to end DST how would we end it. Personally I like to have the extra hour in the evening and would vote for DST all year round.

    Others winge about being dark in the morning and would prefer ST all year long.

  • Joe

    This is somewhat unrelated, but one thing I did not appreciate until recently is that even in Greenwich noon only occurs at noon four times during the year. Because the Earth's orbit is eccentric and the Earth's axis is tilted with respect to its orbit, the length of a day (as defined by the time between the Sun being directly overhead on two successive occasions) varies over the course of a year by up to about 16 minutes from the length of the average day. So even at Greenwich it will generally be slightly before or after noon when the Sun is directly overhead. The Wikipedia article is pretty interesting (or at least I found it to be so): http://en.wikipedia.org/wiki/Equation_of_time

  • Daublin

    Down with leap seconds!

    I don't see how they are valuable to anyone but astronomers, and what good is it really to astronomers? I would think that anyone doing precise astronomic measurements is simply going to need to account for all the factors. If they care about second-level precision, then they won't even want the leap seconds. They'll want to use a daily measured difference between UT1 and UTC in their calculations.

  • Angus S-F

    Time is definitely an "interesting" (as in the Chinese curse "interesting" [Google is your friend here ;-)]) topic. As are calendars .... I've strongly considered changing my celebration of the calendar to coincide with true astronomical events like the solstices and the equinoxes rather than the Western-calendar's arbitrary "New Year" or the "Chinese New Year". Make much more sense to me ... and when you do that, does the "leap second" really matter ?????

  • Griffin3

    Of course, if you properly open-source your time routines, then you get thousands of eyes looking for bugs, rooting them out, making changes within days of laws being changed around the world. Then you reuse that API in all your programming, and never have to worry about the details of time again. Until you have to make something work with the onscure, hidden intricacies of Excel timekeeping, and [insert vague Linuxy rant here].

  • caseyboy

    Finally this blog is addressing the real challenge we face as a nation and a people. Now I know why I have to adjust my wristwatch every couple of weeks. And I thought it was just a little slow.

    I prefer the Lunar calendar. It does not require any machinations or tweaking.

  • caseyboy

    Oh yeah, and it sync's up with your lady's menstrual cycle, always something to be mindful of.

  • I Got Bupkis, AGW Skeptic to the stars

    >>> Time is definitely an “interesting” (as in the Chinese curse “interesting” [Google is your friend here ;-) ]) topic.

    LOL, I'm assuming you're aware that this is actually apocryphal. There's no actual Chinese curse, though there is one that translates into a vaguely familiar form, though clearly not the same translation. It actually begins appearing in English around the 1920s, IIRC.

  • I Got Bupkis, AGW Skeptic to the stars

    On the thread topic, i'm more annoyed with the Fed changing the standard conversion dates which mess up my stupid computer, which is running a MS OS sufficiently old that they don't update it any more, which means my computer clock gets screwed up 4 times a year, when it was supposed to go on/off DT and when it actually goes on/off DT.

  • Roswell Rick

    As a blue water sailor, I'm looking at this from a celestial naviation perspective. Taking a celestial sight requires recording a time accurate to the second and conversion of that time to universal time(UTC). I guess the Nautical Almanac could be adjusted to accommodate this since it already must address other differences between tropical and atomic time (e.g. conversion info for the difference between local apparent noon at Greenwich and 1200 UTC), but in celestial naviation, "Every second counts." With approximately 24,900 statute miles at the equator, the earth's 360 degree rotation means your location is moving 17 miles every minute (quarter mile every second). It doesn't take many seconds to 'leap' to an incorrect location calculation!

  • hanmeng

    I like the idea of going back to everyone having their own time with noon set to local astronomic noon. Mentally correcting the difference between your own location and another would be a problem for most of us, but most of us use technology to check time anyway.

    If you're interested in a lunar calendar, stay away from the Chinese version--since it's correlated with the solar calendar, they periodically get out of sync and add an intercalary month to the lunar calendar.

    And speaking of the Chinese, China only has a single time zone (Peking time) for the entire country, even though the distance from east to west is longer than that of the U.S.