4 ms·
35s is the cumulative sum of all leap seconds so far
by fsk 12y ago
35s is the cumulative sum of all leap seconds so far
- kintamanimatt 12y agoFollow-up question: what's the condition for a leap second to be added?
- viraptor 12y agoChanges in Earth rotation speed. Have a look at wikipedia's "Leap second". It's explained pretty well with some historic data.
- oofabz 12y agoIt sounds like the leap seconds all have the same sign. If corrections are always being applied in the same direction, that implies a second is not as close to 1/86400 of a solar day as it could be. Maybe we should redefine the second. It is currently defined as "9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom." 9,192,631,770 * 35s / 40y ~= 255. If we adjust the definition by 255 periods, TIA and UTC would stay in sync much better.
- jebeck 12y agoWhile all leap seconds so far have been positive, that is not a requirement. Negative leap seconds are a possibility - one accounted for in any valid implementation. More significant for this particular suggestion, leap seconds do not occur/become necessary on any nice linear basis. They are tragically bound to the rotation of the Earth, which does not care about what would be nice for us and changes in a non-linear fashion.
- vilhelm_s 12y agoThe basic problem is that the solar day keeps getting longer. The definition of the second was based on a length-of-day averaged over the 19th century, so now it's too short. We could keep redefining the second every so often, but that sounds even worse than the system we have now. :)
- gpvos 12y agoScientists would hate you if you redefined the second by such a large amount. And since we've delegated the definition of a second to scientists (notably physicists), it's not going to happen.