Keith&Co.
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Wow! They announced a leap second would occur this year on June 30th. They annnounced it back in December i think. We've managed to make it most of the way through March before someone has told me that it's proof of a young Earth. The Earth's spnning down, so we adjust our clocks, all the time ignoring the fact that if this was an old Earth, we'd have slowed to a stop by now, the argument goes.
I JUST wrote the training to give to the submarine missile techs on what a leap second is and how to implement it and the importance. This is a fairly rare event, so they always forget how to do it. The last one was about 18 months ago. The one before that, there was a gap of about 9 years without a leap second.
It's not because the Earth is slowing down its rotation.
I mean, the Earth IS slowing down, sure. The length of a day increases about .004 seconds per year in recent years. That's fine, but we haven't implemented a leap second to correct for this change.
The leap day is easy for everyone to understand. Our calendar assumes 365 days in a year. The Earth's rotation around the sun is not that exact. So we put in a leap day to add up all the errors accumulated over four years, and reset the calendar. If we didn't, then spring would move one day each four years, followed by summer moving 1 day every four years and so on. Over vast stretches of time, the length of a year would not change, but we'd be planting crops on days that used to be the middle of winter or the harvest or whatever.
Leap days don't indicate that the length of a year changes. They just match a theoretical reference to the physical event.
Our clocks assume that the length of a day is 86400 seconds. This is not quite accurate. The Earth wobbles on its axis, the speed of rotation speeds up and slows down, there will be a small, unpredictable but measureable difference between the computed 24-hour day and the actual time between sun-overhead and sun-overhead. The milliseconds of error are tracked and corrected for. When the error reaches around 700 milliseconds, they decide to have a leap second.
The leap second is used to keep the theoretical clock closely aligned to the actual rotation of the Earth. It's not because the day's slowing. If the Earth stopped losing .004 second/year, we'd still need leap seconds.
I JUST wrote the training to give to the submarine missile techs on what a leap second is and how to implement it and the importance. This is a fairly rare event, so they always forget how to do it. The last one was about 18 months ago. The one before that, there was a gap of about 9 years without a leap second.
It's not because the Earth is slowing down its rotation.
I mean, the Earth IS slowing down, sure. The length of a day increases about .004 seconds per year in recent years. That's fine, but we haven't implemented a leap second to correct for this change.
The leap day is easy for everyone to understand. Our calendar assumes 365 days in a year. The Earth's rotation around the sun is not that exact. So we put in a leap day to add up all the errors accumulated over four years, and reset the calendar. If we didn't, then spring would move one day each four years, followed by summer moving 1 day every four years and so on. Over vast stretches of time, the length of a year would not change, but we'd be planting crops on days that used to be the middle of winter or the harvest or whatever.
Leap days don't indicate that the length of a year changes. They just match a theoretical reference to the physical event.
Our clocks assume that the length of a day is 86400 seconds. This is not quite accurate. The Earth wobbles on its axis, the speed of rotation speeds up and slows down, there will be a small, unpredictable but measureable difference between the computed 24-hour day and the actual time between sun-overhead and sun-overhead. The milliseconds of error are tracked and corrected for. When the error reaches around 700 milliseconds, they decide to have a leap second.
The leap second is used to keep the theoretical clock closely aligned to the actual rotation of the Earth. It's not because the day's slowing. If the Earth stopped losing .004 second/year, we'd still need leap seconds.
