Apologies if this doesn’t fit here, not sure where else to post something like this on lemmy
I think having gravity act like weather might be an interesting concept for a fantasy world, where each country has its own gravity patterns, some tend to be heavier some tend to be lighter, some are all over the place
For a few examples, there could be a desert with gravity so high you can get dragged down into the sand
Could be a country with gravity so low everyone uses personal aircraft that work like bicycles instead of land vehicles
Animals in higher gravity areas would have less dense bones, more muscle, etc and lower gravity would have far larger animals because they can support more weight
In a really high gravity area people might need exoskeletons to prevent long term damage
Instead of wind mills, you could have gravity mills. Pump water into a higher-altitude reservoir on low-gravity days, and let it flow down – turning a turbine – on high gravity days. At least electricity would be cheap.
Or if it varies by region, pump water horizontally (or let it flow slightly downward) from a high gravity region to a low one. Then pump the water upwards there, then horizontally again to the high gravity region. Then let it fall down to turn a turbine that runs all the pumps – perpetual motion (ish)!
Predicting tides becomes hard. Everything is going to be really windy all the time, as the atmosphere expands in low-gravity regions and contracts in high gravity ones. This makes tall buildings impractical, as they would also have to be built for some maximum gravity rating on top of the constant gravity storms.
The oceans would be weird, and violent. Hurricanes might get far more powerful than what we deal with, if the right gravity conditions occur.
For any sort of civilization to emerge, gravity would have to change/vary really slowly. I don’t even want to think of orbits. Kerbal Space Program would be like, really hard in that universe.
Oh man I didn’t even think about atmospheric pressure, could giant windbreakers not potentially be constructed to lessen the effect of this wind?
Or maybe in this fantasy world as it has formed originally with these gravity differences there are lots of natural windbreakers, raised areas and lowered areas, mountains etc due to earth getting compacted to different levels
I would imagine the gravity variance within an area would be fairly mild by comparison to the differences between areas - like how you tend to get warmer temperatures near the equator but can still get variances in temp around that
Oceans may become terrifying but it may be easier to travel by air anyway, instead of trying to travel by ocean you could attempt to plot a course through lower gravity areas and avoid the higher ones Could even spawn some badass hardened sea captains that are required to make certain journeys as they are impossible by air
Well if we are going for science…
Giant constructions will have a lot of wear and tear under varying gravity. On top of that, high winds and frequent storms are likely to weather geographical features a lot, making them more flat. In a fantasy world, you can just magic things away, so that’s fine :)
I don’t know about you, but I would find constant high winds fairly terrifying for air travel. Perhaps they are high enough to permit wheeled sailboats on land? That would be creative!
Wheeled sailboats would be very cool, for air travel could have an airbender-like group, a bunch of monks who dedicate their lives to studying the way the wind changes who can instinctively navigate it and use it to their advantage
Aircraft could essentially just be a hang glider with various mechanisms for steering and best catching the wind
I think if I were writing this as a book I’d have to conveniently ignore/find a way to explain away the wind problem though as it would turn the world from a kind of whimsical interesting place to a deadly, unforgiving one.
I also quite like the idea of low gravs having low tech man-powered aircraft instead of land vehicles and wild wind would make that rather impossible
I quite like the idea of wild wind over the ocean for those air nomad people but that might be a case of wanting my cake and eating it too
I guess if I were going the magical route there could be a group of wizards in every town or city maintaining some kind of force field to keep the wind out, taking it in shifts. Could be a major terrorist threat if someone were able to take them down
I suppose wheeled boats are just… cars with sails? Sailcars? Wind chariots?
Hm, one thing I didn’t think about was magma, if the variations are not so small. Going to have more volcanic eruptions, as fluids get pressed out of high-gravity regions and into low-gravity ones (creating big mountains that grow and tumble into the high gravity wells like some sort of horizontal convection?). Earthquakes too, as the high gravity regions sink and the low gravity ones rise creating shear force. I bet the planet would be more “lumpy” than your run-of-the-mill oblong spheroid. I wonder what continental drift would be like?
With that much irregular magma flow, I bet the magnetic field would be weird if it could sustain one at all. Maybe as ‘cells’ where the eruptions occur in low gravity regions, then gets pulled into high gravity regions where it compresses, heats due to radioactive decay, melts and is pushed back out into low-gravity regions. So maybe you’d have ‘local north’ for the cell? Or a very weak magnetic field overall (yay radiation)? I don’t really know on this point.
Oh and exceptionally high-precision clocks won’t be useful except locally, because of the effect of gravity on spacetime, but that doesn’t seem so bad. Low precision clocks based on pendulums won’t be useful at all! Spring escapements should be fine though.
Maybe it would be better to live underwater?
Wow all of that, and home ownership still seems more accessible there than here. I bet real estate prices are a bargain!
I can’t imagine living under water would be much fun either, I imagine the bottom of the ocean in high grav would be absolutely unlivable due to the pressure
Also, I’m not entirely sure how it works but divers have to come out of the water really slowly and carefully so they don’t get the bends, imagine that where the water pressure keeps changing
Infact imagine any underwater structure where the pressure continuously changes dramatically
Also also the tides would be going absolutely crazy overhead
All that said that would make it even cooler to have some kind of hermit character, maybe a powerful wizard living under the sea despite all the hazards and difficulties
As a mercenary science hermit, I approve.
I think I read your title differently - as in, gravity would ebb and flow like wind or rain or barometric pressure or temperature. In normal days the gravity might be mostly constant, or may fluctuate a few percent as the day goes on, rising and falling over the diurnal cycle. But at times a gravity storm could blow through, causing wild fluctuations from just a few percent (or even reversing!) to a couple hundred percent, causing travelers to lose their un-secured cargo or to be pinned in place until the storm subsides. Locals would know the dangers and have things easily tied down, or beds for riding a gravity storm in relative comfort, but any huge storms people would evacuate, praying that the fluctuations wouldn’t destroy their homes or farms. (And now I’m imagining the end of O Brother Where Art Thou with the cow on the roof)
You read it correctly, that’s what I meant. Both different areas with different gravity patterns but also slight variations day to day like the weather with occasional freak occurances
I think reversal would be rare and restricted to very specific areas
Custom gravity beds would be cool. Personally I’d imagine they’d involve being immersed in some kind of ultra buoyant liquid designed not to cause problems with sustained skin contact
Ergonomic chairs, beds etc would be a must too
Sounds pretty heavy.
I think having people travel between them could be pretty weird. John Carter on Mars showed how going to a low gravity place would have some benefits (he could jump around like a flea). The people living on Mars though thought there gravity was “normal” because they’d always experienced it, however they did have simpler flying machines.
But if a creature traveled to a higher gravity zone they’d just be crushed like a human on the sea floor. Would all these monsters creep from the high gravity places and destroy low gravity civilizations?
Would the borders be sharp? What’s driving the differences? Dense unground metal deposits? Wizards?
I don’t think it’s horrible but there’s a lot to be worked out.
I like the underground ore deposit idea but it doesn’t account for gravity changing
I would imagine the gravity change would be gradual rather than sharp, so you wouldn’t just step over a border and be instantly crushed, they’d have fair warning to turn back
Though I imagine it would be an issue similar to how drastic temperature changes are an issue (for example if someone from Finland went to live in Texas and couldn’t deal with the heat or vice versa)
The animals from higher gravity areas would likely be dangerous, however their bodies would likely have evolved to be far less dense, bones could be broken more easily, they could be pushed around more easily/flung into the air and wouldn’t be well equipped to deal with that
Also, guns would still exist, creatures still wouldn’t be able to easily cross oceans so I imagine to a modern society they wouldn’t be too much of a threat in the same way that gorillas are pretty scary up close but aren’t really a problem realistically
Definitely are a lot of finer technical points to work out which is kind of the point of this post, just interested to explore the possibilities
If entering lower gravity areas causes bones and muscle to become less dense, then entering higher gravity areas causes bones and muscle to become more dense. Just look at what happens to those on the ISS after long expose to low g forces. The animals from high gravity areas would likely be shorter, but stronger in musclemass and bone density and/or structure. Higher gravity would also mean higher air density. So maybe the air would be more soupy and difficult to travel through. So perhaps the animals would be more aerodynamic. A stiff beeze would ruin your day!
Ooh interesting point, imagine you go on holiday to a higher gravity area and not only does it become difficult to hold yourself up (might need some kind of protective suit or exoskeleton for tourists to take some of the weight and prevent injury) but also get battered by the wind as you try to move
https://gpg.geosci.xyz/content/gravity/gravity_basics.html
If for some reason the whole planet were made of a less dense material except underneath my house was a massive deposit of gold or lead or something, yes, in reality, that variation in gravity can be measured.
https://bigthink.com/strange-maps/indian-ocean-gravity-hole/
Further reading.
Obviously in your fictional world there has to be a reason tiny anomalies are amped up to eleven. But yes, geology drives gravity variations.
I think the way I’d do it if I were writing a story about this world would be to just not mention the technicalities
Either it’s a medieval level fantasy world where they don’t understand how it works and it’s equivalent to how the sun works or weather works
Or it’s modern day and people generally don’t talk about the finer technicalities the same way people don’t go around casually discussing in detail what causes wind to blow or temperatures to rise and fall
Also, it’s fantasy so it could also just be it works that way because all poweful space cthulu decided that’s how it works
I don’t think your readers would just except that gravity is just smudged across the planet. Sure, some fantasy has iffy rules and little explanation, but something like this smacks more of high fantasy or even scifi.
You don’t need to have a geologist character boring your characters, but some level of lore explaining folke reasons for the variation is going to color your world and sell it.
It will absolutely help to have some hint at an explanation
But if the world is not at the the technological level required to figure it out then it wouldn’t make any sense for them to explain it scientifically
They could perhaps explain it as it is this way because the gods made it this way, or because it’s fantasy it actually could be because the gods made it that way (hence my magic space cthulu comment)
Would all these monsters creep from the high gravity places and destroy low gravity civilizations?
You’ve just reminded me of a book series I started reading a few years ago. I think it was caused by the Earth having much higher gravity than other planets, but the story was basically humans were super strong. Because of this, they could jump long distances and punch through walls.
I’m going to have to start reading it again, if I can remember what it was called.
Really cool concept, this is like an extreme version of our planet; Earth’s gravity is not uniform, there are variations in the gravitational field due to uneven mass distribution.
Was this planet artificially created? I think a hollow, planet sized structure with a small black hole inside that is off-center could give a very noticeable variation in gravity.
Probably pretty dead since you couldn’t have planets with stable orbits.
Variable gravity means its not our universe, So anything is possible.
Maybe the world is on the back of a turtle etc.
I was thinking exactly the same thing, discworld absolutely came to mind thinking about how space might work in this world
If we don’t know what gravity does in this other universe, than talking about variable gravity would pointless.
It is called fiction. They are making it up, the only rules are the ones they decide work for the story.
It can be whatever they want.
See Star wars fighters flying in space like ww2 fighter planes flying in atmosphere.
It can be whatever they want
In fantasy sure. Doesn’t work that well for science-fiction, at least if you want it to be good.
Ah, A Critic!
And one who can judge without actually reading the story.
Impressive skill…
that well for science-fiction
Is Star Wars SF or Fantasy in your world?
I did literally state it was fantasy in the post
Excuse me? Starfield tells me that gravity drives are just around the corner…
In real world terms it doesn’t really make sense, so you’ll need to dial up the “fantastic” when explaining/handwaving it. Ever read Sanderson? Because he does both “reasonably realistic except X” and “this wind is basically a God, whatever, fuck you” and makes both work pretty well.
Oh yeah I do like a good Sanderson book
My thinking was definitely not a realistic/ sci fi world where everything has an explanation, it was just “gravity is like this because it is” and leaving it at that
Just brainstorming a semi-plausible explanations here. What if the variation is due to massive portals/wormholes to other planets? If you’re standing near one that goes to a place with much higher gravity when it opens up, it could cause you to be pulled toward it, or increase gravity around that area. If these portals are kept secret, the gravity fluctuations as they open and close might appear to be as random as weather patterns.
Could be an interesting plot point too, if your story includes races that have secretly come through these portals. Their existence could be discovered by triangulating the gravity changes during an event. Lots of interesting possibilities.
Completely scraping off any astronomical/space problems with this and just rolling along with the idea, which I like, I think your world inhabitants could be either:
- as you said, adapted locally
Or
- with a series of physical adaptations that would allow them to move between areas of different gravity. I think this would make things interesting because you said gravity as weather, and so you could play with the idea of gravitational seasons and gravitational storms or draughts.
Space is kind of a bust, I was thinking this is some fantastical universe where either it’s something like discworld or just magically the effects of the gravity variance are localised to inside the atmosphere
Would be interesting to think about what kind of variants of humans would adapt to their respective areas
You’d need the planet’s core to contain some kind of non-dense material that will not mix with the dense material … like molten rock but also molten something else that’s much lighter than rock. Basically you need “oil and water” droplets that don’t mix, and are of different densities. Then you need some mechanism for them to churn in a turbulent way. The turbulence makes their movements chaotic and unpredictable.
Only thing I can think of to account for the churning is electromagnetic forces being generated by naturally-occurring nuclear reactions.
So to summarize:
- Mantle composed of two substances. One much heavier than the other, and they don’t mix
- Electromagnetic forces occurring at random places and times causes these substances to churn in a turbulent way
- Turbulent churning of these two materials affects the total amount of mass under characters’ feet at different times, causing unpredictable “gravity weather”
- Those electromagnetic forces somehow result from nuclear reactions happening naturally underground (otherwise where do you get the electromagnetism from?)
I think this is my favourite idea so far as to explaining the gravity changes, very cool explanation
If you’re gonna write this book I highly recommend taking a physics class where you study the physics of bounding surfaces and energy flux.
I’m sorry but I don’t remember the exact name of the subject matter. But there are all sorts of interesting properties that different geometric configurations of matter have on the resulting gravitational field (same for sound intensity, electric field strength, etc, anything with an inverse square law).
There are some crazy properties of gravitational fields you wouldn’t expect. Like for instance if all mass was contained in a shell of constant density, then the entire space inside that shell is zero-G, regardless of the shell’s shape.
From outside that shell — say it’s a mickey-mouse-shaped shell of matter that’s uniform in density — you experience the gravitational pull of all of Mickey’s mass toward the centroid of that shape. But from anywhere inside that shell — whether you’re in Mickey’s eye or his heart or the tip of his tail — the pull from all the surrounding matter cancels out and you float in zero-G.
I’m no writer, just like worldbuilding and character building when I have ideas like this
You’d have some wild weather.
Low gravity + strong winds sounds like it would wreck everything and everyone. Hurricanes would turn into a disaster situation rather than a mild annoyance. Imagine cars flying around and ramming buildings.
Ooof yeah natural disasters could be way worse.
There could be entirely gravity based natural disasters too, imagine a gravity quake where gravity rapidly changes between high and low and the havoc that could wreak on structures and people’s bodies
Lumpy.
Of course, if this is a fantasy world you’re under no obligation to go with a world held together by self-gravitation, and you can even ignore the weight of air. Believable water is going to want to follow gravity as usual, though, so you need to figure out some sort of crazy hydraulic system to move it around. It could be a backstory for some cool canyons and things depending on what you decide.
More interesting questions might be related to how the residents adapt. I imagine lower gravity areas would be favoured, with groups living in the high gravity areas being specialised. Maybe unpredictable gravity could serve as an energy source for whatever civilisations are in your setting - you balance a very large weight somehow (against a non-gravitational force or a weight somewhere else), and have it work machinery as it adjusts to a new equilibrium. If it changes rapidly enough it might even be useful at small scales, like on vehicles.
More interesting questions might be related to how the residents adapt. I imagine lower gravity areas would be favoured, with groups living in the high gravity areas being specialised.
You could go with the low gravity areas being sought after, and mostly owned by the rich. Homes are much larger, with ‘floating’ rooms, where you can float around in the low gravity, similar to a private pool. The high gravity areas would be for poor people and manual workers, where everything is blocky and small to compensate.
On the other hand, the high gravity areas could be the most popular, as physical strength is valued, and the people living in the high gravity areas have underdeveloped muscles, so need support suits to be able to visit other areas, and are looked down on for it.
If OP could give other basic information about the setting that would be good. I was assuming there’s multiple people groups involved here, but if it’s all one society then yeah, gravity could be connected with class. The exoskeleton thing makes me think they’re leaning more futuristic.
On the other hand, the high gravity areas could be the most popular, as physical strength is valued, and the people living in the high gravity areas have underdeveloped muscles, so need support suits to be able to visit other areas, and are looked down on for it.
Usually culture follows necessity. I think it probably comes down to if the residents of heavy areas are a ruling military elite, or there’s a great deal of civilian mobility between areas which allows a civilian elite to migrate to easier conditions, and leave the dirty work for others.
I think the people who evolved in the highest gravity regions would become like supermen and end up ruling the whole world due to their superior strength. If not, it would at least give them a significant advantage while technology is still primitive. How would they defend themselves from attack?
See I kinda thought the opposite. I had thought all the wealthy elite would snap up homes in the nice cushy lower gravity areas and have financial power to control the working class living in the harsher, higher gravity areas
To begin with without technology absolutely the higher gravity people would be at the advantage. I imagine the lower gravity areas’ technology would be able to advance much more quickly though, less energy required from their society, so more going spare for research
Also, oceans still exist and as someone else has pointed out would be chaotic and dangerous to cross, so primitive societies would likely have a hard time
There’s also an advantage for low gravity people there in that it’s far easier for them to construct flying machines, so they would likely be far more mobile, and quite possibly first to make contact
Are you assuming there’s the one species who live all over the globe, like humans do? I was coming from the viewpoint that there may be related but divergent species who evolved to different gravity “climates”. I think that might affect the how things turn out to some extent.
Travel around the low gravity areas would be easier, but they would also only be limited to those areas due to piggyback weakness, whereas the people who evolved/grew up in high gravity would be able to travel the earth, so they would be the explorers, merchants and conquerors. Of course as technology advances this will all mean less and less
I can see the low gravity areas becoming prime real estate though, like you said. Talking geologically for a second, my first guess is that these would be higher elevation as the crust isn’t pulled down so much by gravity, and erode slower. Also precious metal deposits might(?) be closer to the surface too. If this is the case then this will give the low G folks to also advance in tech faster with greater access to useful metals. So if they’re quick enough maybe they can defeat the 'heavy’s with ingenuity.
I didn’t really come to a conclusion there did I? I just got more confused the more I thought about geopolitics…
Nothing wrong with not coming to a conclusion the goal is exploration
I am not assuming everyone would be the same physiology, however I imagine when travel becomes viable technologically people will start to mix and so will be varying amounts of high grav and low grav genetics, also I imagine a low grav individual who is born and grows up in a high grav area would end up suited for high grav through just building more muscle
That’s more or less my thinking with high/low grav dominance, much the same as in real life it’ll start out survival of the fittest and as society and technology progresses end up as smarter and/or more wealthy individuals in the lower grav areas taking over
Mechanically, I’d modify the weather table in the DMG:
d20 Gravity
1-14 normal for the season/location
15-17 1d4 × 10 percent lighter than normal
18-20 1d4 × 10 percent heavier than normal
Example: a location that is 200% of normal (all weights doubled) could vary from 160% of normal to 240% of normal.
Roadside Picnic has gravitational anomalies, but they’re very small, don’t move, and are caused by abandoned alien artifacts.