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An Average Earth Day Used To Be Less Than 19 Hours Long (theguardian.com)
Scientists have determined that some 1.4 billion years ago, an Earth day -- that is, a full rotation around its axis -- took 18 hours and 41 minutes, rather than the familiar 24 hours. The Guardian reports: According to fresh calculations, a day on Earth was a full five hours and fifteen minutes shorter a billion or so years ago, well before complex life spread around the planet. Scientists used a combination of astronomical theory and geochemical signatures buried in ancient rocks to show that 1.4bn years ago the Earth turned a full revolution on its axis every 18 hours and 41 minutes. The number means that, on average, the length of the day on Earth has grown by approximately one 74 thousandth of a second per year since Precambrian times, a trend that is expected to continue for millions, if not billions, of years more.
Scientists have determined that some 1.4 billion years ago, an Earth day -- that is, a full rotation around its axis -- took 18 hours and 41 minutes, rather than the familiar 24 hours.
If you're going to go so far as to specify "a full rotation around its axis" - a sidereal day - then you should know that that does not currently take 24 hours. It takes 23 hours and 56 minutes (and 4 seconds).
The article gets it right when it says:
According to fresh calculations, a day on Earth was a full five hours and fifteen minutes shorter
systemd is Roko's Basilisk.
The article (which you can download with Sci-Hub) is not about the length of Earth's day, although it does produce a new and more accurate estimate of it at early epochs on Earth. The paper is really about the Milankovitch Cycle that controls climate on a ~22,000 year time scale which be evident if TFS bothered to include the paper's title Proterozoic Milankovitch cycles and the history of the solar system.
The main purpose of the study was to use geological data to construct the Milankovitch cycle going back more than a billion years.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Not quite. A 3:2 resonance, actually.
Are you posting from the 1960s?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."