Going Round in Circles

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Re: Going Round in Circles

Postby Boreades » 5:22 pm

This ...
https://www.theregister.co.uk/2018/06/0 ... anges_day/

Says ...
Scientists from the University of Wisconsin–Madison and Columbia University found that days on Earth grew longer as the Moon inched further away. Some 1.4 billion years ago, a day lasted just over 18 hours, the researchers found.

Previous simulations showed that when the satellite formed 4.5 billion years ago, it was just 22,500 kilometers (13,981 miles) away. Now, it’s about 400,000 kilometers (248,548 miles) away. Over time, as it spun, the tidal forces between the Earth and Moon has pushed the satellite further away.

The results have been published in the Proceedings of the National Academy of Sciences. The researchers used Milankovitch climate cycles and statistical modelling to study the relationship between the Earth and the Moon.

The Moon is moving away at a rate of 3.82 centimeters per year.


The TME relevance?

c.5,000 years ago the moon was 191 metres closer to Earth. Which was spinning faster, so the day was shorter, and there would be more days in the solar year.

As it was closer, and the tidal forces follow the inverse square law (proportopnal to the square of the distaince), the tides would be higher as well.

As a consistency check:
https://www.universetoday.com/103206/wh ... -the-moon/

Lunar Laser Ranging experiment : From this technique, astronomers have also discovered that the Moon is slowly drifting away from us, at a glacial rate of 3.8 cm (1.5 inches) a year.


I haven't done the maths yet, on exactly how much faster Earth was rotating, but I'm sure it means that back then we were a little closer to 366 days a year.

Of course, this might all be scientific bovine excrement. If the Earth and the Moon has been accumulating mass from space (meteor strikes) then they used to be lighter. Or there might have been a period when they got closer. Does that take us back towards a mythical 360-day year?
Boreades
 
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