Ocean Tides and the Earth's Rotation (2001)
core2.gsfc.nasa.gov
core2.gsfc.nasa.gov
>suppose the rotating earth is our clock and it's been 100 years [...] Then after 1000 days our earth clock loses about 2.3 seconds,
I think the math here is very wrong, or else I haven't had enough coffee yet.
>after 1000 days 1000 * 2.3 milliseconds = 2.3 seconds
I don't think the example helps at all to explain the concept, but I think the math is right
That seems very very fast on galactic time scales - we would get tidally locked (rotate at speed of orbit?) in about 150x43 million … oh about 3 billion years … yeah never mind
Edit A slightly different way of looking at it is we add a leap second every 2 or so years on average (27 in past 53 years). This seems about right with the above maths - it just amazes me
What amazes me more is they are going to stop using leap seconds https://en.m.wikipedia.org/wiki/Leap_second by 2035
If rotation was 86400 seconds per day today, then in 100 years time it will be 86,400.0023 seconds.
In 1,000 years time it will be 23ms slower
In 10,000 years time 230ms slower
In 100,000 years time 2.3 seconds slower.
In 1 million years 23 seconds, a 86400s day will take 86423 seconds
In 43 million years at that speed of 2.3ms per 100 years, a day will take 86,989 seconds, or 24 hours 16 minutes.
(there are other factors effecting earth's rotation)
On average each day over the last 100 years is only about 1.2ms longer, so total extra length after 100 years is 100365.251.15. A cumulative 42 seconds has been added in 100 years.
Charles Petzold - "Computer of the Tides" (2014)