# Will The Earth-Moon System Become "Locked"? **URL:** \ **Category:** Factual Questions\ **Created:** [December 16, 2006, 12:15am UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352 "2006-12-16T00:15:42Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [December 16, 2006, 12:15am UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/1 "2006-12-16T00:15:42Z")
In H.G. Well’s 1899 novel ‘THE TIME MACHINE", the time traveller travels to the far future-to a timewhen the earth stops rotating. The descriptions of this sound haunting…" the eastern horizon was a deep indian red…while the west was black, with bright stars’…the sea was calm, with no waves" Was Wells right? Will the moon eventually cause the earth to stop rotating? ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [December 16, 2006, 12:24am UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/2 "2006-12-16T00:24:33Z")
Well, the moon will eventually “tidal lock” with Earth, in that one side of Earth will be forever facing it, but a _solar_ tidal lock, which is what you’re describing will take a lot longer and the moon will have little to do with it. Of course, long before either happens, the sun will leave the main sequence and swell into a red giant. You’ve got ~5 billion years. Enjoy. ---
**Author:** ![Sapo](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sapo](https://boards.straightdope.com/u/Sapo)\ **Post date:** [December 16, 2006, 12:25am UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/3 "2006-12-16T00:25:18Z")
I understand that our day gets shorter by a second every so many years. So I am guessing yes. ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [December 16, 2006, 12:29am UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/4 "2006-12-16T00:29:09Z")
IIRC the moon will move farther away with time, so the gravitational effects, which so far have not caused the Earth to tidally lock with the Moon, will get weaker with time. IOW it ain’t going to happen. ---
**Author:** ![Sapo](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sapo](https://boards.straightdope.com/u/Sapo)\ **Post date:** [December 16, 2006, 12:34am UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/5 "2006-12-16T00:34:01Z")
Until we build Moon Base Alpha and decide to nuke our compost pile and fly off on the moon to explore the universe. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [December 16, 2006, 12:57am UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/6 "2006-12-16T00:57:17Z")
[QUOTE=Sapo] I understand that our day gets shorter by a second every so many years. So I am guessing yes. [/QUOTE] longer, actually. [Phil Plait's Bad Astronomy: Misconceptions](http://www.badastronomy.com/bad/misc/tides.html) ---
**Author:** ![Sapo](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sapo](https://boards.straightdope.com/u/Sapo)\ **Post date:** [December 16, 2006, 12:58am UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/7 "2006-12-16T00:58:31Z")
[QUOTE=Peter Morris] longer, actually. [Phil Plait's Bad Astronomy: Misconceptions](http://www.badastronomy.com/bad/misc/tides.html) [/QUOTE] d’oh, that’s what I meant. ---
**Author:** ![chorpler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chorpler/32/2888_2.png) [@chorpler](https://boards.straightdope.com/u/chorpler)\ **Post date:** [December 16, 2006, 3:06pm UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/8 "2006-12-16T15:06:28Z")
[QUOTE=John DiFool] IIRC the moon will move farther away with time, so the gravitational effects, which so far have not caused the Earth to tidally lock with the Moon, will get weaker with time. IOW it ain’t going to happen. [/QUOTE] The moon gets farther away because it is “stealing” rotational energy from the earth. Thus, it _will_ eventually tidally lock. Then, effects from the sun would cause the moon to start coming closer to the earth until it passes the Roche limit and breaks up into a glorious ring system. Of course, that won’t actually happen because it would take something like a trillion years. ---
**Author:** ![Otto](https://avatars.discourse-cdn.com/v4/letter/o/bbe5ce/32.png) [@Otto](https://boards.straightdope.com/u/Otto)\ **Post date:** [December 16, 2006, 3:19pm UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/9 "2006-12-16T15:19:27Z")
[QUOTE=Sapo] Until we build Moon Base Alpha and decide to nuke our compost pile and fly off on the moon to explore the universe. [/QUOTE] Dude, that is _sooo_ last century… ---
**Author:** ![AWB](https://avatars.discourse-cdn.com/v4/letter/a/bb73d2/32.png) [@AWB](https://boards.straightdope.com/u/AWB)\ **Post date:** [December 16, 2006, 3:35pm UTC](https://boards.straightdope.com/t/will-the-earth-moon-system-become-locked/384352/10 "2006-12-16T15:35:39Z")
[QUOTE=Sapo] Until we build Moon Base Alpha and decide to nuke our compost pile and fly off on the moon to explore the universe. [/QUOTE] Loved [Space: 1999](http://www.imdb.com/title/tt0072564/)! I know in one episode, Earth managed to communicate with the Alphans. Did they say what happened to the Earth after the Moon left?