# Query about Earth's land mass. **URL:** \ **Category:** Factual Questions\ **Created:** [November 13, 2008, 1:32pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523 "2008-11-13T13:32:53Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![ivan\_astikov](https://avatars.discourse-cdn.com/v4/letter/i/58f4c7/32.png) [@ivan\_astikov](https://boards.straightdope.com/u/ivan_astikov)\ **Post date:** [November 13, 2008, 1:32pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/1 "2008-11-13T13:32:53Z")
I noticed while rotating the globe on Google Earth that there is a pov where all you can see is the bare edges of land masses, and everything else is just ocean, apart from some tiny dotted islands. Does this indicate that the Earth is eventually going to start wobbling like a Weeble through space? Or, is the weight of all that water enough to counter-balance such a tendency? ---
**Author:** ![muttrox](https://avatars.discourse-cdn.com/v4/letter/m/a8b319/32.png) [@muttrox](https://boards.straightdope.com/u/muttrox)\ **Post date:** [November 13, 2008, 1:57pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/2 "2008-11-13T13:57:01Z")
The effect is negligible. The earth is very big and weighs very much, the land mass that sticks up above the water is not as much as you think. ---
**Author:** ![ivan\_astikov](https://avatars.discourse-cdn.com/v4/letter/i/58f4c7/32.png) [@ivan\_astikov](https://boards.straightdope.com/u/ivan_astikov)\ **Post date:** [November 13, 2008, 2:22pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/3 "2008-11-13T14:22:48Z")
So, our rotation when there was only one continent, would have ‘wobbled’ no more than it does now then? ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [November 13, 2008, 2:44pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/4 "2008-11-13T14:44:08Z")
It is not simply that the Earth is enormous as that the oceans are so (relatively) shallow. The deepest part of any ocean is a narrow fissure seven miles down. And while every ocean has one or two trenches, the average depth of the oceans tends to be around 5,000 meters or a little bit less. In contrast, the Earth’s diameter varies from around 12,670,000 meters (pole to pole) to 12,742,000 meters (through the equator), making the “lack” of (surface) land insignificant. Even the change in elevation from the bottom of the Marianas Trench (109,000 meters) to the top of Mount Everest (8,850 meters) only represents .9% of the Earth’s diameter–and that is for anomalies in height and depth. Mountain ranges and ocean depths, (along with ocean sloshing), do have an effect on Earth wobble, but those effects are very small and are also dampened a bit by the molten core. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [November 13, 2008, 3:52pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/5 "2008-11-13T15:52:47Z")
There’s that internet “fact” that’s been going around for a few years now that if you took the earth and shrunk it to the size of a pool ball, it would be much, much smoother than a real pool ball. That is, the change in height from the deepest trench to the higher mountain is much smaller relative to the size of the earth than the irregularities on your average pool ball. I don’t know for sure if that’s true - I’ve just heard it. ---
**Author:** ![JimOfAllTrades](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@JimOfAllTrades](https://boards.straightdope.com/u/JimOfAllTrades)\ **Post date:** [November 13, 2008, 5:47pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/6 "2008-11-13T17:47:19Z")
> [@Smeghead](#): > > There’s that internet “fact” that’s been going around for a few years now that if you took the earth and shrunk it to the size of a pool ball, it would be much, much smoother than a real pool ball. That is, the change in height from the deepest trench to the higher mountain is much smaller relative to the size of the earth than the irregularities on your average pool ball. In this thread: > **[The Earth is not a sphere; but is the Earth's atmosphere a sphere?](https://boards.straightdope.com/sdmb/showthread.php?t=439256)** > > The Earth is a little bit flattened at the poles (or conversely, a little bit bulged at the equator). But is the atmosphere also flattened at the poles? The atmosphere shouldn’t “care” about the shape of the Earth, should it? I mean, the... A couple of dopers calculate that while the earth may actually be slightly more spherical than a pool ball, it is not as smooth when you take into account their relative sizes. From the figures in that thread, it seems like a pool ball sized earth would feel kind of like fine grit sandpaper. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [November 13, 2008, 5:47pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/7 "2008-11-13T17:47:47Z")
The pool ball thing is true. There’s a staff report (or maybe even a Straight Dope column) with referenecs to pool ball specs and everything, but I’m too lazy to search. The Earth is an oblate spheroid, so it’s not as _round_ as a pool ball, but it is smooth enough. ETA: Grrrr… and with a link even. Also, the Earth’s crust, which includes the continents, is less dense than the mantle, so it may be more a matter of the continents “floating” on the mantle. When a floating ice cube melts, the water doesn’t rise, so if you had a water planet with a continent-sized floating ice sheet, I wouldn’t expect that planet to be necessarily unbalanced. A similar thing may be going on here. ---
**Author:** ![Santo\_Rugger](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@Santo\_Rugger](https://boards.straightdope.com/u/Santo_Rugger)\ **Post date:** [November 13, 2008, 6:37pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/8 "2008-11-13T18:37:23Z")
> [@ZenBeam](#): > > The pool ball thing is true. > [@RJKUgly](#): > > From the figures in that thread, it seems like a pool ball sized earth would feel kind of like fine grit sandpaper. One of these things is not like the other. The way I heard it was that it would be smother than a basketball, FWIW. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [November 13, 2008, 7:00pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/9 "2008-11-13T19:00:12Z")
It is worth noting that the Earth _already_ wobbles as it travels through space. While the Moon revolves around the Earth and the Earth rotates upon its axis, the Earth-Moon pair also rotate around [a common center of mass](http://en.wikipedia.org/wiki/Barycenter#Barycenter_in_astronomy). ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 13, 2008, 8:03pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/10 "2008-11-13T20:03:55Z")
> [@](#): > > The way I heard it was that it would be smother than a basketball, FWIW. Oh, that’s easy. A basketball isn’t very smooth at all. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [November 13, 2008, 10:25pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/11 "2008-11-13T22:25:30Z")
Kansas, however, is [flatter then a pancake](http://www.guardian.co.uk/education/2003/sep/25/research.highereducation2). ---
**Author:** ![mlees](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@mlees](https://boards.straightdope.com/u/mlees)\ **Post date:** [November 13, 2008, 10:54pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/12 "2008-11-13T22:54:09Z")
> [@KneadToKnow](#): > > It is worth noting that the Earth _already_ wobbles as it travels through space. While the Moon revolves around the Earth and the Earth rotates upon its axis, the Earth-Moon pair also rotate around [a common center of mass](http://en.wikipedia.org/wiki/Barycenter#Barycenter_in_astronomy). There is also an axial wobble which is a little over 25,000 years per cycle: [Axial precession - Wikipedia](http://en.wikipedia.org/wiki/Procession_of_the_equinoxes) Additionally, there is a slow variation in Earth’s tilt: [Axial tilt - Wikipedia](http://en.wikipedia.org/wiki/Axial_tilt) ---
**Author:** ![squeegee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/squeegee/32/14537_2.png) [@squeegee](https://boards.straightdope.com/u/squeegee)\ **Post date:** [November 13, 2008, 11:03pm UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/13 "2008-11-13T23:03:35Z")
Then there’s [nutation](http://en.wikipedia.org/wiki/Nutation), as long as we’re cataloging wobbles. ---
**Author:** ![garygnu](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garygnu/32/2924_2.png) [@garygnu](https://boards.straightdope.com/u/garygnu)\ **Post date:** [November 14, 2008, 12:29am UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/14 "2008-11-14T00:29:52Z")
> [@Santo\_Rugger](#): > > One of these things is not like the other. > > The way I heard it was that it would be smother than a basketball, FWIW. Not a Straight Dope column, but the next best thing, erstwhile Doper Phil Plait in his [Bad Astronomy blog](http://blogs.discovermagazine.com/badastronomy/2008/09/08/ten-things-you-dont-know-about-the-earth/). It’s smooth enough but not round enough for a pool ball. ---
**Author:** ![The\_Hamster\_King](https://avatars.discourse-cdn.com/v4/letter/t/8edcca/32.png) [@The\_Hamster\_King](https://boards.straightdope.com/u/The_Hamster_King)\ **Post date:** [November 14, 2008, 12:37am UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/15 "2008-11-14T00:37:51Z")
> [@tomndebb](#): > > The deepest part of any ocean is a narrow fissure seven miles down. Wow, that’s deep! Has anyone ever explored it? ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [November 14, 2008, 1:16am UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/16 "2008-11-14T01:16:38Z")
Yes, sometime ago, and only briefly. ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [November 14, 2008, 2:37am UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/17 "2008-11-14T02:37:35Z")
> [@ivan\_astikov](#): > > I noticed while rotating the globe on Google Earth that there is a pov where all you can see is the bare edges of land masses, and everything else is just ocean, apart from some tiny dotted islands. Does this indicate that the Earth is eventually going to start wobbling like a Weeble through space? Not to worry. Weebles wobble — _but they don’t fall down._ Others have said why we don’t have to worry too much about this. I’ll just also point out that the planet has been lopsided in this way for at least 250 million years, back to the time of the Pangea supercontinent, when all the Earth’s land was even more bunched together than it is today. It hasn’t been a problem yet. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [November 14, 2008, 9:29am UTC](https://boards.straightdope.com/t/query-about-earths-land-mass/472523/18 "2008-11-14T09:29:01Z")
> [@tomndebb](#): > > Even the change in elevation from the bottom of the Marianas Trench (109,000 meters) to the top of Mount Everest (8,850 meters) only represents .9% of the Earth’s diameter–and that is for anomalies in height and depth. Just a nitpick, but you got a factor 10 too much in your Marianas Trench depth, so that the actual height variance is more like .16%.