The variability of the earth-rotation vector relative to the body of the planet or in inertial space is caused by the gravitational torque exerted by the Moon, Sun and planets, displacements of matter in different parts of the planet and other excitation mechanisms.
Archiv: Zeitrechnung / time calculation
In Earth’s early history, a day was 23.5 hours and a year lasted 372 days
(13.03.2020)
We’ve long known that an Earth day lasts 24 hours, and that remains constant because Earth’s trip around the sun doesn’t vary.
However, the number of days that make an Earth year have shifted and shortened because days have grown longer. That is thanks to the moon’s gravity, which draws on ocean’s tides and slows Earth’s rate of rotation.
Eine Schaltsekunde mehr Zeit
(30.12.2008)
Wie unregelmäßig sich die Erde dreht, sieht man daran, dass zwischen 1999 und 2006 sieben Jahre vergehen mussten, bis eine Schaltsekunde nötig wurde; diesmal sind es nur drei Jahre.
On-Time Earth Baffles Scientists
(31. März 2003)
To make the world’s official time agree with where the Earth actually is in space, scientists in 1972 started adding an extra „leap second“ on the last day of the year.
For 28 years, scientists repeated the procedure. But in 1999, they discovered the Earth was no longer lagging behind.
At the National Institute for Science and Technology in Boulder, spokesman Fred McGehan said most scientists agree the Earth’s orbit around the sun has been gradually slowing for millennia. But he said they don’t have a good explanation for why it’s suddenly on schedule.
On-Time Earth Baffles Scientists
(31. März 2003)
To make the world’s official time agree with where the Earth actually is in space, scientists in 1972 started adding an extra „leap second“ on the last day of the year.
For 28 years, scientists repeated the procedure. But in 1999, they discovered the Earth was no longer lagging behind.
At the National Institute for Science and Technology in Boulder, spokesman Fred McGehan said most scientists agree the Earth’s orbit around the sun has been gradually slowing for millennia. But he said they don’t have a good explanation for why it’s suddenly on schedule.
In Earth’s early history, a day was 23.5 hours and a year lasted 372 days
(today)
We’ve long known that an Earth day lasts 24 hours, and that remains constant because Earth’s trip around the sun doesn’t vary.