Physics/Geologists Question - Making Fantasy World and Want some Help Theorycrafting

EncEnc A Fool with CompassionThe Land of Flowers (and Dragons)Registered User regular
edited October 2 in Help / Advice Forum
So my next D&D campaign is going to be a 1914/WWI era campaign set in a world reminiscent of the The Princess and the Pilot. For those unfamiliar with the series, the world's oceans have huge fucking waterfalls at regular intervals due to some kind of bizzare tectonic and tidal forces that allow it to work something like this:

mou4y0skl4k5.png

Obviously such a world is unlikely to work by real-world physics, but if it were what sort of lunar/tidal forces would be needed to cause water to push up those ramps to the waterfalls across the oceans? What sort of things should I include in worldbuilding to ~suggest~ that it might be plausible without really going into detail. It's for D&D so it doesn't need to be scientifically accurate and I can come up with semi-magic tecnobabble if I have to, but something rooted in actual planetary physics and gravity would be cool to know.

Any help is appreciated!

Enc on
Dark Raven X

Posts

  • HefflingHeffling No Pic EverRegistered User regular
    You could a very large and/or dense moon which will have much stronger gravity, and thus much stronger tidal forces will be created. So that when the moon is on one side of the world, the water is pulled against the walls, and when it's other the other it's pulled away. Or, if you really want to go crazy, have it be part of a binary planet system in close proximity. Same tidal force idea, but lots more Spelljammer or other offworld shenanigans possible.

    I would avoid tectonic reasons (high speed rotating core, etc) because you'd also get lots of earthquakes and such.

    Or if you want to go with a magic explanation, there are lots of tie ins to the Plane of Water. For example, this world could have an unusually weak veil between itself and the PoW, which evidences itself as the waterfalls. Or in ancient times, a mage failed to correctly cast a 10th level spell that would have bound an extremely powerful water elemental lord to him, and the waterfalls are the remnants of that spell. If you go with the latter, you could even have something like a large continental desert (think Sahara) which could be where the original spell was cast.

    Or maybe there's a continual supermassive storm system that takes days or even months to rotate around the world, and the waterfalls are caused by the storm flooding certain areas of the world.

    Or leave it as an unknown bit of lore. Maybe it occurs periodically and predictably, so that ship navigation is possible. But all of the teams that have attempted to go into the depths of the ocean to determine what causes this phenomena have disappeared.

    Or it could be an old god that is trapped under the oceans who is trying to free itself, and the waterfalls are a side effect of its efforts. In this case, you could have the waterfalls becoming less predictable and more dangerous over the course of many generations (old records show the first waterfall didn't occur until 800 years ago, and the next record of one is from 25 years later. Now they are a monthly occurrence). This could be combined with the previous example.

    This also has a ton of potential as a steampunk type of settings. If the waterfalls are plentiful and predictable, then hydroelectric power could be prevalent by 1914. and you could lean into the weird science side of it.

    If a movement doesn't have someone that can sit down opposite those in a position of power and strike a deal, how can that movement achieve success?
    HappylilElfDisruptedCapitalistDark Raven XSiskaAegis
  • EncEnc A Fool with Compassion The Land of Flowers (and Dragons)Registered User regular
    The hydroelectric and moon stuff are exactly what I'm looking for.

    So if you were standing at one of the falls areas, when the moon is overhead the water would be flowing like crazy, when the moon is on the opposite side it would probably settle, if not become bare rock for a while, and then repeat as a low/high tide cycle?

    Heffling
  • HefflingHeffling No Pic EverRegistered User regular
    tides-new-moon.png?1

    If a movement doesn't have someone that can sit down opposite those in a position of power and strike a deal, how can that movement achieve success?
    HappylilElfRoyceSraphimspool32
  • EncEnc A Fool with Compassion The Land of Flowers (and Dragons)Registered User regular
    Perfect, thanks!

  • BouwsTBouwsT Wanna come to a super soft birthday party? Registered User regular
    Enc wrote: »
    The hydroelectric and moon stuff are exactly what I'm looking for.

    So if you were standing at one of the falls areas, when the moon is overhead the water would be flowing like crazy, when the moon is on the opposite side it would probably settle, if not become bare rock for a while, and then repeat as a low/high tide cycle?

    You could also go full Interstellar and have your world orbiting a black hole instead of having a moon causing these crazy tidal forces.

    I shall be telling this with a sigh
    Somewhere ages and ages hence:
    Two roads diverged in a wood, and I—
    I took the one less traveled by,
    And that has made all the difference.
    SoggybiscuitSmrtnikMugsley
  • CaedwyrCaedwyr Registered User regular
    Something to keep in mind, is that water erodes and waterfalls disappear with time. If you are looking for a geological explanation for why there are waterfalls across the ocean, then to be thorough there needs to be a reason that they appeared somewhat recently (on geological timescales). You could make it something that has happened recently within recorded history, or make it something that has been around for a long time and the waterfalls are more worn down. It could be that the cliffs under the waterfalls are more resistant to erosion somehow.

    On Earth there's actually a water elevation difference of about 0.4 m between the Pacific and Atlantic Ocean at the Panama Canal, so tidal effects caused by the moon or a combination of other heavenly bodies could produce a larger bulge. Greater tidal forces from moons may have a side effect of increasing volcanic and tectonic activity, if we look at the example of the moons of Jupiter or Saturn, but that's with a very large gas giant in close proximity to the moon. Maybe making the planet a moon of a gas giant, but further out could plausibly create more of a balance that allows for the larger tidal effects without causing tectonic effects.

  • Inquisitor77Inquisitor77 2 x Penny Arcade Fight Club Champion A fixed point in space and timeRegistered User regular
    Hear me out:

    magnets

    ElvenshaeBouwsTKetarDisruptedCapitalistRingoDarkewolfeEchoDarkPrimusL Ron HowardMugsleyTofystedethspool32Aegis
  • BouwsTBouwsT Wanna come to a super soft birthday party? Registered User regular
    Hear me out:

    magnets

    Water is a dipole...

    I shall be telling this with a sigh
    Somewhere ages and ages hence:
    Two roads diverged in a wood, and I—
    I took the one less traveled by,
    And that has made all the difference.
  • SanderJKSanderJK Crocodylus Pontifex Sinterklasicus Madrid, 3000 ADRegistered User regular
    Also consider that a close, big moon also undergoes very hefty gravity itself. Depending on the masses and distances involved the tidal heating (The difference between the gravity on the near and far side of the moon) could be enough to make it permanently volcanically active.

    This not only looks cinematic, but also gives you some Extra Bad Weather (As a mega eruption rains hot rocks down on the planet)

    Steam: SanderJK Origin: SanderJK
    RingoElvenshaeTofystedeth
  • CaedwyrCaedwyr Registered User regular
    For extra weird planetary conjunctions, you could have a situation where the world is a rocky planet orbiting around two gas giants in a binary configuration. This could give phases where there are greater and lesser tidal pulls. Perhaps having some periods where the oceans are navigable like out world and some times where ridges and spreading centers become exposed, producing falls or island ridge chains that only can be navigated through by those knowing the secret routes.

    Auralynx
  • EncEnc A Fool with Compassion The Land of Flowers (and Dragons)Registered User regular
    What would cause the waterfalls to be more or less constant aside from #magic?

  • DisruptedCapitalistDisruptedCapitalist screaming Registered User regular
    What about a moon with a highly elliptical orbit. When it's at its apogee it has minimal tidal effects. But when it's at its perigee it has extremely violent effects.

    More fun: have it's orbit take several months so it creates seasonal flooding.

  • CaedwyrCaedwyr Registered User regular
    edited October 3
    I would guess that there is an orbital mechanics configuration with multiple planets/moons that could create a standing wave situation. Or it could be a plausible reason if you don't look too closely.

    You would probably still get wane and waxing intensities in the waterfalls, but I could squint and believe that such a setup could produce the effect you are looking for.

    Caedwyr on
  • PhyphorPhyphor Building Planet Busters Tasting FruitRegistered User regular
    What about a moon with a highly elliptical orbit. When it's at its apogee it has minimal tidal effects. But when it's at its perigee it has extremely violent effects.

    More fun: have it's orbit take several months so it creates seasonal flooding.

    A moon must remain within the vicinity of its planet to stay in orbit. Eg if the moon was highly elliptical it could only have a period at most 30% longer than it currently does - and that orbit may not be stable

    Being a moon orbiting a larger planet is your best bet to get weird effects like this

  • EncEnc A Fool with Compassion The Land of Flowers (and Dragons)Registered User regular
    Phyphor wrote: »
    What about a moon with a highly elliptical orbit. When it's at its apogee it has minimal tidal effects. But when it's at its perigee it has extremely violent effects.

    More fun: have it's orbit take several months so it creates seasonal flooding.

    A moon must remain within the vicinity of its planet to stay in orbit. Eg if the moon was highly elliptical it could only have a period at most 30% longer than it currently does - and that orbit may not be stable

    Being a moon orbiting a larger planet is your best bet to get weird effects like this

    I think this is the angle I'm going to go.

    DisruptedCapitalistElvenshae
  • GnizmoGnizmo Registered User regular
    Enc wrote: »
    What would cause the waterfalls to be more or less constant aside from #magic?

    So with some fuzzy science a highly dense moon/binary planet could potentially cause it. If the object were tidally locked it would create a permanent high tide. This would also pull the liquid magma beneath the surface of the planet to the surface in a similar manner. It might lead to more volcanic eruptions and thus a constant rebuilding of the water falls. This would cause a rather nasty bunch of side effects as well that I won't pretend to understand. I have a loose grasp of the astronomy of it, but not the full geology of it.

    Basically only one side of the planet would see the moon and the other side never would. Nothing would prevent a collection of dense moons. On of the theories for our moon is that something big hit us (the basis of a lot of astronomy) and split off part of the planet. It could happen a couple times in smaller amounts to create a series of effects.

    Definitely a situation that wouldn't hold up to strict scrutiny, but nothing fun ever does. It would give a plausible explanation with some science behind it though.

  • CaedwyrCaedwyr Registered User regular
    Being a moon orbiting a binary planet (gas giant) with other moons and maybe even a moon around the world on which all of this set could give you a lot of plausible deniability to play with here for a non-magical explanation and can also provide some really handy "conjunction of the planets" type timing triggers to explain why some sort of magical/non-magical thing can be done now, but not always.

    RingoSiska
  • RoyceSraphimRoyceSraphim Registered User regular
    Continent periodically rises on a set cycle and falls over time?

  • discriderdiscrider Registered User regular
    Heh.
    Something driving a wave at the resonant frequency of the planet causing a standing wave in the tectonics that oscillates different axii and continents of the planet up and down.

    Steam Community page: http://steamcommunity.com/id/discrider/
    Some sorta sentient internet aggregator
  • DarkewolfeDarkewolfe Registered User regular
    edited October 4
    Hear me out:

    magnets

    How would they work?

    Darkewolfe on
    What is this I don't even.
    MugsleyElvenshae
  • schussschuss Registered User regular
    I'd vote for "well, a long time ago some mages thought waterfalls were neat and were a bit fuzzy on efficient spell creation. So now we have a LOT of waterfalls and thanks to some quick thinking and longstanding effort, we've patched things so we don't all drown."
    Also opens things up for weird magical contraptions they can encounter.

  • Inquisitor77Inquisitor77 2 x Penny Arcade Fight Club Champion A fixed point in space and timeRegistered User regular
    Darkewolfe wrote: »
    Hear me out:

    magnets

    How would they work?

    Nobody knows.

    DarkewolfeMugsleyElvenshae
  • SiskaSiska Shorty Registered User regular
    Twin moons orbiting each other. Have some wild tidal fluctuations depending on how they line up. They could be different color. Legends and religions with conflicting stories about how that are lovers in an eternal dance or warriors in combat. There could be a gradual magnetic particle build between them that causes spectacular aurora borealis effects once every few decades that is the cause for worldwide celebrations and religious nuttery.

    Izuela.png
    Elvenshae
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