My magic system transfers quantities of certain properties from one object to another. For instance, electrical conductivity from metal to rubber -- the metal becomes less conductive, and the rubber becomes more conductive.

To transfer properties, you need special equipment and fuel proportional to the quantity to be transferred. The fuel is decently difficult to create.

There would be a point of diminishing returns, after which exponentially more of a property must be taken from one material to give a lesser amount of the property to the other material.

The magic has only been known for 50-ish years, and is a well-kept secret of a particular tribal people living on a coastline. They have access to native metals, and have been learning to mine and refine metals for the past 30-ish years, and can make steel with difficulty. They can make glass. They do not know how to make gunpowder.

The coast they are living on is a fault coastline, similar to Chile, but the world also has extreme tides and regularly occurring tsunami, such that there is not much sand or dirt along the coast. The tribe lives there because of political force, spiritual connections to the land, and to create the fuel for the magic (the ingredients for which can only be found on the coast)

Current ideas for transferable properties:

  • Electrical conductivity
  • Thermal conductivity
  • Specific heat
  • Boiling point
  • Melting point
  • Freezing point
  • Ductility
  • Malleability
  • Hardness
  • Tensile strength
  • Color
  • Transparency
  • Density
  • Elasticity
  • Resistance to corrosion
  • Flammability (Ignition temperature)
  • Friction
  • Magnetism

Which 7 properties are best for creating tsunami-resistant buildings which can be submerged for extended periods?

The general design for buildings would be dome-like, since I understand that spheres and cylinders tend to resist tsunami more effectively than cubes.

(If a material property not listed here occurs to you and would be very useful, it would be much appreciated. Otherwise, only consider the properties listed.)

  • $\begingroup$ I'm concerned that the question is going to elicit primarily opinion based answers, and it is rather broad at the moment as you've specified several parts of the building which presumably would need to have their own different properties. Perhaps you could break it up into several seperate questions. VTC POB. $\endgroup$ – Hoyle's ghost Mar 16 at 12:30
  • $\begingroup$ Im also concerned that is a duplicate of this question: worldbuilding.stackexchange.com/questions/141087/… $\endgroup$ – Hoyle's ghost Mar 16 at 13:29
  • $\begingroup$ @Arajag I was encouraged to break the linked question into multiple, more specific questions. This is the first of those more specific questions. Should I delete the old question? I have also removed air supply from this question, so that it is only about the best material properties to make a rounded structure most tsunami-resistant. $\endgroup$ – 007th Bondsmith Mar 21 at 12:58
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    $\begingroup$ I'm not around for a few hours, but I promise to get back to you later with something (hopefully) helpfull. :-) $\endgroup$ – Hoyle's ghost Mar 21 at 13:10
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    $\begingroup$ Bondsmith The recent edit has narrowed it somewhat and it's been nominated for reopening, we'll see what the reviewers think, then hopefully it'll be running again soon. $\endgroup$ – Hoyle's ghost Mar 21 at 16:02

I think the most useful property for building to survive a tsunami would be elasticity. Specifically, having elastic properties near the base of the building. Some skyscrapers in Japan have shock-absorbant bases which allows them to reduce the forces from an earthquake. A similar idea could apply here, if the tsunami hit the building and, rather than falling over, the building bent to absorb the force (and returned to its previous shape when force was not being applied) it would be more likely to survive.

If you wanted the building to stay submerged for long periods of time, you could have tubes like giant straws which float on the surface of the water (which is what i think you were implying in your question).

However, i suggest permeability as a transferrable property. You could make the outside of the buildings semi-permeable in that they allow for oxygen atoms to pass through to pass through the walls, allowing the people inside to breath whilst keeping safe from the water.

As an alternative answer, i suggest buoyancy as a transferable property. So how this would work is you’d have your domes on the ground attached to anchors with chains. The domes would be very buoyant in the water. When the tsunami comes, you stay in your dome and ket the water fill the space above you. When it settles, you can ‘drop anchor’ (like in a ship) and your domes would float to the surface of the water, allowing people to breathe indefinitely. The anchors and chains stop the building from floating away so that when the water returns to sea, the buildings naturally float back down. You would also pull the chains to respool them so you don’t have chains laying around everywhere.

  • $\begingroup$ Elasticity makes a ton of sense! Thanks! Isn't buoyancy the result of density? So, I could rename density to buoyancy, since I'm separating out hardness and such. $\endgroup$ – 007th Bondsmith Mar 21 at 13:08
  • $\begingroup$ Is permeability just a sliding scale, or are there different types of permeability? (i.e. is 5 arbitrary units of permeability enough to let in oxygen, but not water, whereas 7 au would let in both oxygen and water? Or are there various kinds of permeability such that two materials can have the same level of permeability, but one lets in oxygen, and the other doesn't let in oxygen, but only lets in water?) $\endgroup$ – 007th Bondsmith Mar 21 at 13:09
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    $\begingroup$ @007thBondsmith Yes, i think density and buoyancy are linked. So a block of wood floats as it is less dense than the water around it. I said buoyancy in my answer as i felt it was an easier way of describing it. Plus, you are more likely to associate water with buoyancy rather than density. $\endgroup$ – Liam Morris Mar 21 at 15:14
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    $\begingroup$ @007thBondsmith Permeability is a sliding scale, think of it like having holes in the dome. The holes are just big enough to allow singular oxygen atoms in but they’re too small to let water molecules in. $\endgroup$ – Liam Morris Mar 21 at 15:22

It's not so much what the buildings are made of but more how they are made.

The fact there isn't much dirt or sand is a good thing. Means you're dealing with rock and rock strong enough to resist the tides and waves. Good foundations is the important thing.

Design wise you have two options,

a tower which stays above the water

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or an dome design that will trap air while submerged and refresh after the water subsides

Your magic allows the building to be built easily but said building need to be anchored to the stone. I see the locals forming walls of mud/clay before imbuing them with the hardness of stone and flexibility of the seaweed, materials that should be easily found locally. Transparency can be transferred for windows and skylights and colour for ascetics.

A building with the hardness of granite and flexibility of seaweed firmly anchored to the bedrock should resist the worse the ocean can throw at it.


I don't know how critical it is for you that the tribe lives in "traditional" buildings at all and what technology they have available but I'd suggest a different approach.

The tribe could live in the ground similar to cave homes or dugouts (like in Australia for example), which should also be feasible with any technology considering they could make the rock soft and just dig it out like dirt or something. They could also manipulate the rock above and surrounding their homes so that the material gets more resistant to erosion and to keep moisture out. They could have dome-like entry points, made out of hardened glass or steel for example, with airlocks so they can enter and exit the complex even when submerged. Or use an underwater cave if they don't have the technology available. Like with any submerged building they'd have a problem with ventilation but then they could for example also use moored buoys with hoses connected to the complex.

Another idea would be to use houseboats or some kind of ark which are moored to the ground. The chain and hulls of the boats could be reinforced with the magic to withstand the forces when a tsunami hits. The people could maybe even freeze the surrounding water for pathways between the boats.

The (additional) hardness could in any case be transferred from the bedrock a few hundred meters away or so, so that their ground doesn't get washed away. Or from the rock they dug out for their homes of course.

Hope this helps a bit.


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