The slowing of the Earth’s rotation is an ongoing process. It has been going on for billions of years and will continue for billions more. But “billions of years” isn’t forever. It will eventually happen. I don’t know the exact number but it has been calculated, and observed. IIRC, it will take about 2 billion more years, so we are about 2/3rds of the way through the process. The Sun will run out of fuel (Hydrogen) in about 5 billion years, so the Earth-Moon system will become tidally locked long before that happens.

There are at least 2 direct physical observations that directly support this. I think there are ancient sedimentary rocks (100’s of million years old) that show there were more days in a year than there are now (i.e. the Earth rotated faster), and direct measurements of the distance to the Moon using the Apollo laser reflectors show that the Moon is receding from the Earth, another consequence of the same theory.

Phil (& Co.),
Please read this following excerpt from your article:

“Despite all this confusion, the Earth’s rotation is in fact slowing down. Eventually, the Earth’s rotation will slow down so much that the bulge will line up exactly between the centers of the Earth and the Moon. When this happens, the Moon will no longer be pulling the bulge back, and the Earth’s spin will stop slowing. But when this happens, the time it takes for the Earth to rotate once will be slowed to exactly the same time it takes for the Moon to go around the Earth once! If you were to stand on the Moon and look at the Earth, you would always see the same face of the Earth.”

Phil’s scientific and predictive explanation raises some questions:

Why hasn’t this already happened?
(If the solar system is billions of years old?)

Maybe, the solar system, let alone universe, isn’t that old!

Chris

cgegere@tctwest.net

John

To me, that seems practically the same as saying, when the Sun is over the equator. I.e., when the latitude is zero.

I thought the USNO’s definition of the equinox was when the Sun was at apparent ecliptic longitude of 180 degrees. I wonder what the time difference has been over the centuries?

Of course, if you grew up in Boulder on “The Hill” like I did, you’d understand that we actually have 4 seasons in Colorado: Almost Winter, Winter, Still Winter, and Construction…