If the entire Earth's gravity immediately shifted so it was pulling from East to West, what should people do? Keep in mind that this is not reversed, but merely tilted sideways, and maybe at an angle slightly downward so that everything doesn't just fly off into space. Would it be better for everyone to stay put, or try to find a common meeting place. My initial thought was the Svalbard seed vault or some place similar, although there would be terrible constant rainstorms (the oceans would be falling), and it might become so icy that travel would be nearly impossible. How long could anyone survive, and how should they do it?

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    $\begingroup$ what happens at the poles? $\endgroup$
    – Snyder005
    Commented Aug 30, 2016 at 3:10
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    $\begingroup$ Uh... I don't think you understand how gravity works.... $\endgroup$
    – Aify
    Commented Aug 30, 2016 at 3:40
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    $\begingroup$ @Aify Since this question is in regard to a world where gravity doesn't work properly, I'm not sure knowing how actual gravity works is terribly important. $\endgroup$ Commented Aug 30, 2016 at 16:19
  • $\begingroup$ @MozerShmozer because what OP describes doesn't make sense. "Gravity that pulls slightly downwards" is relative to the person the gravity is affecting, and where they are on the planet. $\endgroup$
    – Aify
    Commented Aug 30, 2016 at 16:24
  • $\begingroup$ Worldbuilding ... not. $\endgroup$
    – Karl
    Commented Aug 30, 2016 at 20:26

7 Answers 7


The Earth would fly apart. Gravity pointing downwards is all that keeps this ball of dirt and metal holding together in space. If that force is no longer pointing downwards, I would expect something like this would happen (as viewed from a point above the Earth's north pole):

new direction of gravity 1 pt 2 pt 3

It is important to note that "East" points in completely different directions depending on where you are on the Earth's surface, hence the rotational symmetry of the above images.

In this scenario, the Earth is reduced to a disk of rubble rapidly spreading out into space. Nobody survives. NoTHING survives, except maybe lithophagous bacteria living deep inside rocks.

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    $\begingroup$ I wish I could upvote once for the concept and againg for the graphics :v $\endgroup$
    – Theraot
    Commented Aug 30, 2016 at 6:39
  • $\begingroup$ +1 please may I request u replace Earth with Sun I like to see supernova for once. $\endgroup$
    – user6760
    Commented Aug 30, 2016 at 7:08
  • $\begingroup$ Thanks for the graphics, although I did put in a stipulation that gravity would pull at an angle slightly downwards to keep it from falling apart. $\endgroup$
    – margalo
    Commented Aug 30, 2016 at 14:12
  • $\begingroup$ @margalo The effects on the Earth's structure would still be catastrophic. Millions of tons of rock would shift thousands of miles in the mantle. I don't know what shape the Earth would turn out in, but assuming the surface stayed intact it would probably become a raging ocean of lava. $\endgroup$ Commented Aug 30, 2016 at 16:50
  • $\begingroup$ @ApproachingDarknessFish I don't think humanity would be around long enough to enjoy it though. The massive, global tsunamis would wipe us all out fairly quickly. $\endgroup$
    – IchabodE
    Commented Sep 18, 2017 at 21:37

Greg Egan wrote a story about that! You can read Bit Players on-line for free.

Sagreda looked back over her shoulder, only to be dazzled again by the rising sun. “Can you tell me what’s happened to the world?” she pleaded.

“Are you saying you’ve forgotten the Calamity?” Gerther asked skeptically.

“What calamity?”

“When gravity turned sideways. When it stopped pulling us toward the center of the Earth, and started pulling us east instead.”

Not only does it cover the absolute absurdity of the idea within the story itself, but the characters exploit the nonsense physics to produce power and start an advanced civilization underground.

It is well worth reading the full short story. Anything by Egan is recommended as masterful lessons in worldbuilding.

Since the premise is nonsensical, to the point that handwaving and unknown extra details are needed to make a small cave setting work at all, we really can’t answer your question. You, the author, would need to introduce other unexplained details or inconsistencies to further your plot, and can make it “work” however you needed it to work out.

An older novel, On by Adam Roberts (pointed out by a4android) also has a plot of a sideways gravity world that presents as an endless cliff. I’ve not read it, but it involves a great deal of travel and adventuring in this environment.

This might be the real novel mentioned in the short story and expresses Egan’s own impression of the concept:

It was as if someone had tried to invent an exotic new world, but knew so little about the way the real one worked that all they could come up with was a dog’s breakfast of contrivances and inconsistencies.

…this world is based on an obscure pulp novel called East, by a man named William Tush.”

William Tush appears to be a fake name, and zero point energy is mentioned in the story, and the form of the character’s names (Tighe, Wittershe vs Johnhis, Gissher, also noted as silly within Eagan’s story) is clearly mimicing the other, so I suspect Eagan’s story is a reaction to the shoddy worldbuilding in On. Others agree.

After all, there were no premises that could give rise to both the believable local physics of the everyday objects around her and the Road Runner cartoon laws that the world required to hold up on any larger scale.

I suspect that anything the OP does with the concept would share the same fate, unless it’s full blown meta “this universe is ridiculous” like with Bit Players, or the effect is thought out better somehow.

  • $\begingroup$ Thanks a lot— I didn't realize the concept had been explored so much already. $\endgroup$
    – margalo
    Commented Aug 30, 2016 at 14:16
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    $\begingroup$ Appreciate your addition of the link to Roberts' ON (2001). Excellent expansion of your answer to include the possibility of Egan reacting to Roberts' worldbuilding. That really puts the icing on the cake. Well done, sir. $\endgroup$
    – a4android
    Commented Aug 31, 2016 at 6:18

Setting the where aside for a moment, I think the first question is how would your average person go anywhere in that case?

If gravity were to suddenly start pulling everything sideways at 9.8 m/s², then anyone who happened to be outside at the time is probably already dead. They would have "fallen" sideways (or been dragged along the ground, if the pull is sideways and slightly downwards), accelerating until either they reached terminal velocity or until they slammed into the nearest building, tree, or cliff. Basically anyone more than about 20 feet from a vertical surface is likely to sustain serious injuries when the gravitational pull shifts, if they're not killed outright. In either case, those people aren't likely to be going anywhere.

Your most likely survivors will be people who were inside of buildings at the time. And probably only smaller, wider buildings, with a low center of gravity, as skyscrapers probably cannot withstand a 1G horizontal load. So a person inside of a house, for instance, has a decent chance of surviving the transition. So too does the house, if it has a deep/well-anchored foundation. The person inside could move around (inside the house, that is) by walking on the walls. Once they want to go outside, it's another problem entirely.

If gravity is pulling things sideways, then essentially every door in every house/building now opens to a sheer cliff. To go anywhere, a person needs to traverse that cliff. Which for a person of average strength/physical fitness and not in possession of advanced rock-climbing knowledge and equipment is going to be virtually impossible over any nontrivial distance. Maybe a professional climber who happened to survive the initial event unscathed and had their equipment on them at the time would be able to make some progress. However Joe Average is probably screwed once all the food in the house is gone.

But let's assume you've got someone who survived the gravitational transition and is able to move about (and let's assume that the planet hasn't torn itself apart or otherwise been rendered completely uninhabitable...which is liable to happen from a strictly scientific standpoint but also not really any good for storytelling). Where do they go? I can think of a few options:

  • Forests - If you can safely reach a dense forest (and it's still standing; taller trees may well suffer the same fate as skyscrapers), you may be able to use the trees to move around more easily. Moreover, they may provide a source of shelter, and any birds and other small woodland critters that survived may provided a source of food (which is easily accessible, as "climbing" a tree is now as easy as walking horizontally along its trunk). Over time you could potentially construct walkways/bridges and similar structures to make moving around easier and safer.

  • Shopping Centers - Think grocery stores, malls, and similar buildings that tend to be large, short, wide, and solidly constructed. These may still be largely intact, would provide a decent-sized surface to move around on, and will contain extensive stores of preserved goods that you're going to need in order to survive. If you can get inside they might provide some decent shelter as well, although the typical layout (large, cavernous interior spaces) might make this quite hazardous. Given sufficient time and resources, however, you could potentially rework all of that interior space in a way that better accommodates sideways gravity.

  • Natural Cliffs - Ideally you want to get back into a situation where a large area of solid ground exists in the "downwards" direction. The best option for that sort of thing would be eastward-facing cliffs, and/or mountain ranges (if they're steep enough). Cliffs located near farmland/fertile soil might be ideal, as with a bit of effort you should be able to liberate some of that soil (if the gravitational transition didn't do so on its own) and relocate it to your cliffs. Then you could look at reestablishing basic agriculture, expanding your living area by quarrying the surrounding area, and possibly creating a tunnel network to access nearby locations of interest.

  • $\begingroup$ (1) You say, "every door in every house/building now opens to a sheer cliff." But in fact, some walls will be "horizontal", and some will be sloped. (2) You mentioned staying in your house until all the food was consumed. You should note that toilets probably won't work correctly. (3) My first thought on reading this was "Forests! — That's brilliant!" But, on further thought, wouldn't tall trees have the same problem as sky scrapers? (Consider what wind can do to a tree. Compare to a persistent (permanent) lateral force that's equal to the weight of the tree.) Continued ... $\endgroup$ Commented Aug 30, 2016 at 17:35
  • $\begingroup$ ... Continued: (4) You mention "westward-facing cliffs." I may be confused, but I believe that eastward-facing cliffs would be the safe ones. But how many cliffs are perfectly aligned along a north-south meridian? It might be better to find a tall/steep mountain. (If it's round enough and big enough (in circumference), then it will have a "top" surface, just like a tree.) (99) Good answer! $\endgroup$ Commented Aug 30, 2016 at 17:36

If the entire Earth's gravity immediately shifted so it was pulling from East to West, what should people do?

Nothing. Everybody would be dead within the next 15 minutes (at max). Most would be dragged brutally on the surface and slammed against buildings, trees or mountains. Others would be brutally hit by rocks, vehicles, other people, animals and all other heavy things which would be rolling westwards at a speed which begins at 35 km/h and increases by 35 km/h every second.

I haven't done any in-depth research, but I would wager all human population would be dead within the next 15 minutes, all mammals within 1 hour, all vertebrates within 90 minutes and practically every form of macroscopic life within the next 1 day.


First, we have to ignore...

We ignore the destruction of the planet itself. We ignore physics, too. So we'll set that aside and treat this as more of a problem for life on earth than a fundamental problem with the universe itself.

First moments

In the first moments after gravity goes sideways, everyone who is outside is gone. Hikers, joggers, walkers, people going about their daily lives on the planet's surface suddenly shoot sideways and fly out into space, accelerating at 9.8 meters per second per second until they reach terminal velocity. Or until they impact with a building or a mountain , etc. between them and space -- those folks become a red smear on the side of whatever they hit. Much like a bug on a windshield. Either way, they die. So do all the other animals. There will be much screaming.

And all the kids' toys and cars and trucks, and loose pebbles, and large rocks, and landfills full of garbage, and your Amazon delivery sitting on the front porch, and anything else not attached to the planet goes flying off into space. Suddenly the debris field surrounding out planet just got more crowded.

People inside factories or garages or anywhere where sharp things exist in the path of your decent towards the wall will be impaled and die either quickly or slowly, depending on the nature of the impaling item. There will be much screaming.

People in restaurant or home kitchens will have to worry about falling into hot stoves, deep fryers and other nasty things. Or having those things fall into you. Hot grease flies out of deep fryers. Knives and chopping blocks and hot pans and vats of hot soup go flying into people and buildings. There will be much screaming.

Indoors and underground

Indoors and underground, people, furniture, pets, house plants, dishes, TVs, and everything else suddenly slams with extreme force into the walls. People will die. Other people will have broken limbs or bloody noses. Some people will die later because there's no way to get them to hospitals. People in the hospitals will face a harder time. Some things will slam into windows, shatter those windows, and become part of the debris cloud around the planet. There will be much screaming.

Mobile homes and houses that aren't well anchored will also fly off to join the debris cloud. Probably shattering into rubble as they fly off. Rocks and cars will impact against buildings, destroying them and adding to the flying maelstrom of death.

Some people will die in the clouds of debris. Others will die of asphyxiation once they get far enough out. Or cold. Regardless, there will be much screaming along the way.

Planes, trains, and boats?

At any given moment, about 5,000 airplanes are in the air. These planes will have some seriously bad turbulence. The pilots, strapped into their seats, should be okay once they get control of the planes. The ones near the ground will probably crash as gravity flips them out of control for the first few moments. The ones higher up will avoid that fate, but they probably cannot land. Sure, they could approach the ground. But they cannot land, because if they slow below stall speeds, they'll fall with gravity. So they'll die more slowly than the rest, at least.

Boats will slip sideways in the ocean. This will either flip them over on their sides (since the keel of the boat will be pulled slower than the portions out of the water), or will lift them entirely from the water. Either way, bad day to be at sea.

Trains will derail instantly, then crash out into space. Subways will derail and slam into the walls of subway tunnels. Those who survive this crash might be able to escape by climbing out of the tunnel walls. Maybe.

Submarines, if they don't smash into the sea floor, will probably give you the best odds of survival for the short term of any transportation means. The sub can rotate until down is down, and keep going for as long as the ocean is stable.

Goodbye, ocean

The ocean won't be stable for long. It will surge over land and, eventually, into space. Coastal regions will either become landlocked within minutes, or be washed away in the worst tidal surge ever, depending on whether they are east or west coastal facing.

Goodbye air

And then, of course, let's not ignore the hurricane-force winds that will rip things apart as all of our air flies off into space.

Final results.

The Earth is a cold, desolate, lifeless region with no hopes of recovery. You know, after all the screaming is done.

I feel like this should be an XKCD What-If response.

  • $\begingroup$ "The earth is a cold, desolate, lifeless region with no hopes of recovery." But planet Earth is still there? $\endgroup$
    – user
    Commented Sep 18, 2017 at 14:09

Well first things first gravity would not just suddenly be pulling to the west, although polar shift is a thing http://www.nasa.gov/topics/earth/features/2012-poleReversal.html and there are actually several fantasy books that use this as one of there story driving forces although any titles escape me at the moment.

HOWEVER: baring the fact that it doesn't happen lets say a god or gods go and say "yeah, all this stuff.... its gonna start falling this way".. the first thing that would happen would be that anything on the western side of the planet would be gone into space, even when you say that it is slightly angled downward there is always a place on a sphere where slightly downward is going to (unless gravity started moving in a circular motion essentially from east to west but that is a whole other problem.) result in being pulled off of said sphere (earth).

so here are my 10 predictions that i think would happen NOTE: I am not a physicist or gravitational scientist of any kind just some one who enjoys these kinds of problems.

1: the western hemisphere would be uninhabitable to a point.

2:Anyone who was in the Western hemisphere is probably dead or really badly injured.

3:ocean levels would sink in the east and rise in the west, by how much i have no idea.

4: our atmosphere would maybe begin to siphon off (not sure on this one)

5: things like building, monuments, and the such would collapse due to stress they were not designed for killing millions.

6: people caught up in this would "fall" sideways probably dragging on the ground until they could grab something and/or die from getting dragged into a building or something.

7: cars would not work even if they were right side up due to gravity pulling gas down into the gas intake pipe (or whatever it is called.)

8: most (if not all) animals and fish would loose their balance and in the case of underwater mammals (i.e. dolphins) would drown as they swam against gravity trying to surface for breath.

9: birds would not be able to fly unless they figured out how to fly upside down. (same goes for planes, they would have to launch only in the east and never fly into the west or they would loose and be sucked into space.

10: Life would most likely end for Planet Earth.

SO to be totally honest i would try and make my way to a swing-set and at least be able to sit comfortably and see a really unique sunset and wait for the world to end.

  • $\begingroup$ (1) If the OP says that gravity will suddenly start pulling to the west, what basis do you have for saying, "No, that won't happen"? (2) What is "the western side of the planet"? (3) "cars would not work even if they were right side up" Huh? What? (4) Dolphins normally "swim against gravity" when they go to the surface. It's not clear what would happen to the oceans, but I don't see dolphins drowning as being a problem. (98) I believe you're misunderstanding the premise of the question. See the other answers to understand the question. (99) Please use correct capitalization/punctuation, etc. $\endgroup$ Commented Aug 30, 2016 at 17:39
  • $\begingroup$ A polar shift has nothing to do with gravity. The theories on that are about magnetic fields, with the more extreme also including a shift in the axis of rotation. $\endgroup$ Commented Aug 30, 2016 at 18:18
  • $\begingroup$ Again like i said in the question im not a physicist or anything like that this is just where my mind went while reading the other answers/comments and i am well aware that polar shift has nothing to do with gravity, this just reminded me of it and therefor made the statement that it was a thing. I never said that it affected gravity. $\endgroup$
    – Akmedrah
    Commented Aug 30, 2016 at 19:11

Gravity is so powerful, every object on the earth would suddenly be pulled to the "east". When I say on the earth, I mean if it isn't rooted several hundred feet into the crust. If there was only a slight downward pull to keep the earth from flying apart, there would be nothing but dust as everything was ground into a fine powder against the surface of the earth. Of course the ocean's, lakes, and rivers would turn that dust to mud. You'd end up with a planet of swirling mud.

There would be no safe place for a human in such a world. Except maybe a surfer or snowboarder...they might survive until they starved or fell asleep and fell off their boards.


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