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    Re: Leap seconds
    From: Greg R_
    Date: 2009 Jan 10, 13:00 -0800
    George:
     
    Are you reading this? Because this is EXACTLY what I was referring to earlier (i.e. that whatever time scale we use as navigators is totally irrelevant - as long as we can correlate it to the time in an almanac, or whatever is used to obtain the date/time for a celestial event).
     
    I still don't know if you were being troll-ish earlier or honestly trying to contribute to the discussion, but at least I'm not the only one who understands the concept - however abstract it might be for some on the list to comprehend.
     
    --
    GregR
     
     
     
    ----- Original Message -----
    From: "Gary LaPook" <glapook---.net>
    Sent: Saturday, January 03, 2009 9:42 PM
    Subject: [NavList 6893] Re: Leap seconds


    Navigators can deal with any time scale. The ordinary people might be
    able to deal with the occasional leap second , they don't even notice
    since they don't care about precise time, they don't worry about he
    accuracy of their watches (like we do) and most of use have clocks and
    cellphones that are set automatically. But what about when the clocks
    says noon and it is the middle of the night? even the ordinary people
    will notice.

    I remember back during the fuel crisis of the '70s when the idea of
    going on DST all year round was proposed the ordinary people protested
    "we don't want our kids going to school in the dark" and the farmers
    complained " the cows don't like being milked in the dark." The ordinary
    people didn't understand that they could just change the number of the
    hour of school time and milking time and keep the same schedule in
    relation to sun time. So I don't think they will do well unless we keep
    our ordinary time close to sun time.

    gl

    frankreed{at}HistoricalAtlas.com wrote:
    > Geoffrey, last week you wrote:
    > "Is there any reasonable and accurate account available of the UK's current
    > argument within the working group of the ITU, in which the UK rejects the
    > abolition of leap seconds?"
    >
    > I haven't been able to find anything like that, but there is a detailed argument against the abrupt and unconsidered abolition of leap seconds here:
    >
    http://www.ucolick.org/~sla/leapsecs/
    >
    > Lots of useful details, some nice graphs on the "figures and tables" page. Some of the information is out-of-date, but it's still good reading.
    >
    > One thing struck me while reading on that site (not something that he directly points out). The real risk from keeping leap seconds might not be ordinary leap seconds but the possibility, which might still happen, of a negative leap second. It's very easy to imagine computer systems which would do this incorrectly. Even without that risk, I still think it makes good sense to drop leap seconds due to the smaller risk from programming positive leap seconds.
    >
    > If you read comments from "ordinary people" (and I saw you posted at The Times site so I would guess you read some of those), you may notice that people are easily worked up by the thought of arbitrary changes to their time systems. This can get out of hand if the reasons for the changes are not explained carefully and in clear terms. I was reminded of an exchange between two prisoners in the gulag in Solzhenitsyn's "One Day in the Life of Ivan Denisovich." One character says, "Since then it's been decreed that the sun is highest at one o'clock." The other wonders, "Who decreed that?" And the first answers, "The Soviet government." It's supposed to be a wry comment on the absurdity of the Communist government: who but the Soviets would think to order the Sun to change its time?! What they're talking about is Soviet (and now Russian) "decree time" which sets clocks about one time zone ahead year-round (with Summer Time additional). There's nothing necessarily wrong with it, and it's not an example of a government gone mad. But time is something that everyone thinks they understand. For example, 'noon: that's when the Sun's straight overhead,' right? :-) Everybody "knows" that, and if governments or scientific bodies try to change it, they must be corrupt. As I say, that's the big risk in not explaining this correctly.
    >
    > I think the important point that needs to be made in communication with the public is that we gave up "sun time" long ago. In fact, I would say we've given it up three times. First, in the late 18th century (and not until 1834 in the Nautical Almanac), when we abandoned local apparent time for local mean time. Clocks replaced the Sun, but on average they still agreed within 20 minutes. Second, in the late 19th century, zone time replaced local mean time. That added up to an hour of difference but usually less than thirty minutes. And most recently, in the early and mid 20th century, "Summer Time" or DST added another hour of difference. In other words, today, we keep time by the Sun only in the most general sense; it should be daylight in mid-latitudes when the clock says "noon". Dropping leap seconds will not change that. Your post on The Times site was right on the mark: if we can deal with "Summer Time," then we can deal with the abolition of leap seconds.
    >
    > -FER
    > PS: while looking for some further thoughts on Soviet "decree time", my googling led me to a post regarding the time of launch of some satellites for the Russian Glonass system, and the poster asked whether that time was Russian decree time or not. Small world that this is, the poster was NavList member Richard Langley.
    >
    >
    >
    > >
    >
    >  


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