Should we abolish the leap second?

Quote: reno

Couldn't the leap second be combined with the leap year so that we could deal with both anomalies simultaneously? Surely waiting til 2016 couldn't have hurt. Computers don't need nice round numbers, they're okay with a leap day of 23 hours, 59 minutes and 59 seconds +/- leap second, or whatever.

Keep the housekeeping efficient, I say.

I don't think it would matter for the disruption as computers and atomic clocks are already programmed for the leap year but not the leap second.

Quote: reno

Couldn't the leap second be combined with the leap year so that we could deal with both anomalies simultaneously?

No but yes.

Leap seconds don't happen every year. And there may be more than one. You could keep them and add them only on leap years. I don't know if that would be better or not.

I think there is a leap second about once every one or two years. So if we waited for a leap year then we would need a few leap seconds to catch up. I also don't think the leap seconds are as predicable as leap years. We seem to add them on an as-needed basis.

On a somewhat related topic, which is the official clock of the United States? I always thought it was the Atomic Clock in Colorado but I think there is another one at the Naval Observatory in DC (where the vice president lives) that is the official one. At least that is what I was told by somebody who used to work there. As always, please correct me if I'm in error.

Also, which is the official clock of Mexico?

Quote: Wizard

I think there is a leap second about once every one or two years. So if we waited for a leap year then we would need a few leap seconds to catch up. I also don't think the leap seconds are as predicable as leap years. We seem to add them on an as-needed basis.

On a somewhat related topic, which is the official clock of the United States? I always thought it was the Atomic Clock in Colorado but I think there is another one at the Naval Observatory in DC (where the vice president lives) that is the official one. At least that is what I was told by somebody who used to work there. As always, please correct me if I'm in error.

Also, which is the official clock of Mexico?

I always thought Colorado, that is the one that broadcasts on shortwave radio. Time to hear it on your radio is more inaccurate than the clock. Maybe where the VP lives is an old one?

Quote: Wizard

On a somewhat related topic, which is the official clock of the United States? I always thought it was the Atomic Clock in Colorado but I think there is another one at the Naval Observatory in DC (where the vice president lives) that is the official one.

The first really practical, important use for accurate timekeeping was in navigation. An accurate clock is used to determine longitude. I'm not sure how, but it involves synchronizing the shipboard clock, called a chronometer actually, with a land-based clock, measurements of the Sun's angle might be involved, too.

So, yes, the official timekeeping fell to the Navy.

But these days there are many atomic clocks, accurate to insane degrees, and used for many reasons, timekeeping being only one. GPS uses atomic clocks in orbit, and the extreme accuracy is very useful in physics. I think some encryption systems require them, too. I know these insanely precise clocks can measure time dilation in aircraft.

Quote:

Also, which is the official clock of Mexico?

There is one??

Quote: AZDuffman

I always thought Colorado, that is the one that broadcasts on shortwave radio. Time to hear it on your radio is more inaccurate than the clock. Maybe where the VP lives is an old one?

I don't know if there is an "official" clock of the US, but Coordinated Universal Time is evidently an average of about 300 atomic clocks around the world. -- source

Quote: reno

Couldn't the leap second be combined with the leap year so that we could deal with both anomalies simultaneously? Surely waiting til 2016 couldn't have hurt. Computers don't need nice round numbers, they're okay with a leap day of 23 hours, 59 minutes and 59 seconds +/- leap second, or whatever.

Keep the housekeeping efficient, I say.

Leap seconds are a lot more common than leap years. They have only been adding the leap second since 1972. The leap year goes back to 45 BC.

1972 JAN 1
1972 JUL 1
1973 JAN 1
1974 JAN 1
1975 JAN 1
1976 JAN 1
1977 JAN 1
1978 JAN 1
1979 JAN 1
1980 JAN 1
1981 JUL 1
1982 JUL 1
1983 JUL 1
1985 JUL 1
1988 JAN 1
1990 JAN 1
1991 JAN 1
1992 JUL 1
1993 JUL 1
1994 JUL 1
1996 JAN 1
1997 JUL 1
1999 JAN 1
2006 JAN 1
2009 JAN 1
2012 JUL 1
2015 JUL 1

Interesting how inconsistently they add leap seconds. There was one every year from 1972 to 1983 and then only four between 2000 to 2015.

Longitude by time is pretty straightforward.

The clock on the ship is set to GMT

The difference in time on the ship clock and the time as reported by the sun tells you how far around the world you are.

If the sun says it is noon, and your clock says it is midnight, you are on the opposite side of the world.

If your clock says it is noon, and the sun says it is 9am, you are 1/4th along the way to the west, or 45 degrees west longitude.

I should add that the time the sun tells you is "natural" local time, where noon is always when the sun is at its highest point.

Quote: Wizard

I don't know if there is an "official" clock of the US, but Coordinated Universal Time is evidently an average of about 300 atomic clocks around the world. -- source

When we were at sea it was often called CUT "coordonné universel temps" time (I know Nareed, the acronym includes time and it shouldn't be repeated). It is the world standard since 1960 and Greenwich Mean Time no longer has official meaning. GMT can differ from CUT or UCT by less than a second.

The leap seconds cannot be predicted far in advance due to the unpredictable rate of rotation of the Earth.

https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment
As Nareed mentioned, they have verified since 1971 that the relativistic effects are measurable by the speed of jets. Changes are measured in nano seconds. I don't know if UTC smallest divisible increment would be. I don't think it goes below the micro second.