This question is about attaining the technology required to build a spaceship. The asserted duplicate question assumes that technology already exists.

In order to build a spaceship, you need to:

  1. Form steel with machine tools.
  2. Ditto aluminum.
  3. And titanium.
  4. Smelt iron from ore and add precise amounts of carbon to make steel.
  5. Smelt titanium from ore.
  6. Electrically split aluminum from bauxite ore.
  7. Refine chromium,vanadium and all the other trace minerals needed for steel.
  8. Mine the iron ore.
  9. Ditto titanium ore.
  10. Ditto bauxite.
  11. Mining operations are incredibly complex.
  12. The mining operations, as well as the smelters, forges, machine shops, etc, all need energy -- lots of energy -- which is mined/pumped from the ground.
  13. And electricity.
  14. And a way to generate lots of electricity.
  15. And transmit it thousands of miles.
  16. None of that technology burst forth whole from our brains. It all took many centuries -- even millennia -- of development.
  17. And all requires fire.
  18. And the ability to move and lift staggering amounts of stuff across vast distances.
  19. Members of your species have to transmit all this information to others (remembering that oral tradition cultures have not developed spacecraft).
  20. Which means some form of writing.

How do you do that when:

  1. your species has no legs,
  2. water attenuates light, and
  3. water extinguishes fire, and
  4. there's no evolutionary advantage to hands underwater (otherwise, some species would have developed them)?
  • $\begingroup$ @shitty_author That question says "organise its spaceship interior", not "develop the technology to create a spaceship". Thus, not a duplicate. $\endgroup$
    – RonJohn
    Mar 19, 2018 at 22:49
  • $\begingroup$ Possible duplicate of How would an aquatic, air-breathing species organise its spaceship interior? $\endgroup$
    – Tim B II
    Mar 19, 2018 at 23:02
  • $\begingroup$ @TimBII at the top of the question, I explained why it's not a duplicate. $\endgroup$
    – RonJohn
    Mar 19, 2018 at 23:05
  • $\begingroup$ Alright, I understand your point. I was looking at it from the perspective that space ship design pretty much dictates how it's organised internally. Besides, your answer to this specific question is they can't because as you point out, they need massive amounts of heat and water conducts heat too well for (say) a smelting industry to exist underwater without devastating effects to the ecology. $\endgroup$
    – Tim B II
    Mar 19, 2018 at 23:12
  • $\begingroup$ @TimBII but that would mean that asking how an aquatic, air-breathing species organizes its spaceship interior in an invalid question. $\endgroup$
    – RonJohn
    Mar 19, 2018 at 23:15

1 Answer 1


Crabs have legs and pincers, octopuses are quite dexterous, there's little reason to think intelligence could not evolve underwater indeed octopuses, cuttlefish and dolphins all exhibit advanced cognitive skills.

Fire isn't strictly necessary for metalworking, it's possible to heat metals with induction and if electric eels and the field sensing ability of sharks are anything to go by it's entirely possible this alien species has an innate ability to sense and manipulate small amounts of electricity. If anything they would be baffled as to how we developed transistors considering that on land the only naturally occurring electricity that we can sense is lightning and that's not something that can be easily studied.

The same geology exists underwater as on land so mining isn't that much different, ventilation is perhaps more of an issue for them (pumping water around being more energy intensive than moving air) but they don't have to worry as much about cave-ins (the water pressure helps to prevent the mine collapsing) or flooding because the mine is already flooded.

Speaking of energy they'll probably start with wave and simple solar power systems, as we started with windmills and water wheels, then move to combustion (we have diesel powered submarines, a water world will still have an atmosphere) burning coal and oil if they're available or maybe some kind of biofuel if they're not.

There's certainly difficulties to be overcome but nothing that we couldn't have overcome given the same circumstances, indeed being terrestrial may have seriously hampered us in ways we won't know about until we meet such a species.

  • $\begingroup$ What the reality-check of crabs and octopuses forging iron? How much to they mine and build? Do electric eels split aluminum from bauxite? $\endgroup$
    – RonJohn
    Mar 20, 2018 at 5:26
  • $\begingroup$ @RonJohn Considering that limpet teeth have a hardness up there with the likes of diamond, a crab with a claw strong enough to double as a pickaxe or hammer/anvil is probably possible. The lack of pain/heat-receptors in the shell will probably help in forging too. As to "how much" - how big are your Brachyura Sapiens? That's going to make a huge difference. As will culture - do they even bother with houses, or just have a patch of sea floor to sleep on? $\endgroup$ Mar 20, 2018 at 11:43
  • $\begingroup$ An intelligent tool using species isn't going to mine and build with its bare appendages just as we don't dig with our hands and do woodworking with our teeth. Likewise if they can naturally generate electricity that doesn't mean they'll be using that to get aluminum from bauxite, instead I'm saying their electrical abilities/senses will make studying electricity and developing electronics easier. $\endgroup$
    – Cognisant
    Mar 20, 2018 at 23:14
  • $\begingroup$ @Cognisant but they -- at some point -- have to make the tools with their hands. And quite a lot of electricity is needed to extract aluminum from bauxite. $\endgroup$
    – RonJohn
    Mar 21, 2018 at 14:55
  • $\begingroup$ @RonJohn Of course they need to make tools, I'm saying there's no reason to think you can't make tools using tentacles/pincers and if they're making tools they can make generators and batteries and apparatuses to extract aluminum from bauxite. If your aliens are like dolphins and they don't have the means to precisely manipulate their environment they're not going to be able to invent anything. $\endgroup$
    – Cognisant
    Mar 22, 2018 at 4:17

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