2
$\begingroup$

So, I'm interested in a humanoid civilisation, only it develops underwater, in a world with no ground above sea level. I want to know, considering ignition with a spark would be, well since, fire and water don't mix, how would they create explosives?

What materials would they use?

Improve this question
$\endgroup$
20
  • 1
    $\begingroup$ Unless the humanoids came from elsewhere, I wouldn't expect humanoids at all. $\endgroup$
    – Monty Wild ♦
    Commented Oct 26, 2023 at 3:55
  • 1
    $\begingroup$ Can you tell us what you've tried to find out and what level of technical sophistication your society has developed? The more I think about it the more show stoppers I see, e.g. no electrolysis at high pressure, not sure if stone flint lives in ocean floor geology but maybe quartz and thus piezo electric igniters, chemistry of any kind is quite different to deal with. But deep ocean is unfamiliar territory for humans, so I'm not used to thinking about how stuff would work. $\endgroup$
    – Nolo
    Commented Oct 26, 2023 at 4:15
  • $\begingroup$ Around our technology, if that would be possible. Otherwise, any technology level where it would work. I hope that's not too vague $\endgroup$
    – boboranonymous
    Commented Oct 26, 2023 at 4:16
  • 1
    $\begingroup$ Alright, but our level of technology did not develop under water, so our set of options for figuring stuff out and engineering things is quite different. So there's a very large hump of missing knowledge to overcome. With much more thought and theory it may be possible to derive a sort of way to get somewhere close to there from here. I'll think on it a bit and try later. :-) $\endgroup$
    – Nolo
    Commented Oct 26, 2023 at 4:19
  • $\begingroup$ If it doesn't get closed. Be sure to read about how to ask questions here and update with the kind of information we need to help you get a reasonable answer. $\endgroup$
    – Nolo
    Commented Oct 26, 2023 at 4:20

2 Answers 2

Reset to default
2
$\begingroup$

I would expect underwater technological evolution to have gone without fire which is one of the biggest parts and driving forces behind our own human technology. Chemistry, metallurgy etc,. wouldn't really exist or be severely hampered.

They can still create explosive type forces using hydraulics and kinematic transmission which would be highly advanced within the limits of their resources. Mantis shrimp for instance pack a crazily powerful strike underwater. So the same forces which allow clams to move, mantis shrimp to punch and enable jet propulsion in squids would all be useful.

Improve this answer
$\endgroup$
6
  • $\begingroup$ I'll give you that chemistry is hard and alien to us under water, but is it off the table? $\endgroup$
    – Nolo
    Commented Oct 26, 2023 at 18:50
  • $\begingroup$ @Nolo I would think so, I can't imagine how they would work out the periodic table or any of the basics in a salt water medium $\endgroup$
    – Kilisi
    Commented Oct 26, 2023 at 20:19
  • $\begingroup$ @Nolo the big problem is it is easy ot isolate solutions on land, you can use containers that you can mix and pour from and you can evaporate things to get solids, nether work underwater. $\endgroup$
    – John
    Commented Oct 30, 2023 at 19:50
  • $\begingroup$ @John yes, I recognize that. Any kind of solution would be incredibly complicated and would almost certainly not involve drying things. However, I have to assume there are interesting things to learn by pushing knowable boundaries within those constraints. For example, the fact that lighting is electricity and it's the same thing as static shocks on door handles, and moreover, that it's intimately related to magnetism, were revelations for us. But we can assume that underwater civilization might know something about electric eels and be curious about biology. $\endgroup$
    – Nolo
    Commented Oct 30, 2023 at 20:31
  • 1
    $\begingroup$ @Nolo but without an insulator or metals experiments can't be done, water is too good a conductor. you can't even build a simple battery or wire underwater. static doesn't build up underwater so they wouldn't even have that to learn from. there have been a lot of questions about technology underwater. $\endgroup$
    – John
    Commented Oct 30, 2023 at 20:45
2
$\begingroup$

Possibly the same, possibly different

Okay - so a wonderfully 50/50 answer.

Well - let's look at why it might be the same - consider Nitroglycerine. It's one of the older explosive compounds and it has a medicinal use.

The Medicinal use part is important because it gives an in-world justification as to why a civilization that doesn't use gunpowder, would 'discover' an explosive compound. Once discovered and various uses are found, more explosive compounds would likely be found and the process better understood etc.

So - why start with Nitroglycerine? Well, apart from the plausibility of it's discovery - it's an explosive that is shock-sensitive. That means, no flame or electricity needed to set it off - perfect for an underwater environment.

It's shock-sensitivity also provides a justifiable reason as to why additional research and discovery of new explosive compounds would happen.

That's the evolutionary path of the discover of an explosive compound and why they would seek to discover more.

However, where things will rapidly diverge is that underwater, the propagation of a blast wave is much different than in air - Explosives can be much more destructive because of the multiple impulses.

This means that the types of Explosive used, how they are used etc. will be significantly different. You would likely see less push towards more explosive power, you wouldn't see the development of things like EFPs - although you may still see shaped charges to maximize the effect of the hydraulic forces/Cavitation from the water.

In short - once shock-sensitive explosives are 'discovered' - via Medical research first stop would be to make them more stable, then other ways to initiate the explosive. From there, the properties of being underwater would cause a divergence in the research paths.

Improve this answer
$\endgroup$
3
  • $\begingroup$ Good answer. I suspect that chemical engineering is the biggest hurdle. That's what drew a lot of blanks for me. Though I admit little knowledge of chemistry to begin with. How then would we produce nitroglycerine under water? Or are there alternatives to consider? Lots of stuff races around, super saturation, deep sea vents and so on. :D Can you provide any hints that may help? $\endgroup$
    – Nolo
    Commented Oct 26, 2023 at 18:43
  • $\begingroup$ I know that iodide contact explosives come out of a wet precipitate and must be dried to work, so we'd have to steer around such problems. $\endgroup$
    – Nolo
    Commented Oct 26, 2023 at 18:44
  • 1
    $\begingroup$ @Nolo - I agree that it's the biggest hurdle - however, since the OP has indicated 'around our tech level' - I'm inferring a handwave around the chemical engineering challenge - that they either have 'clean rooms' or 'non-reactive rooms' or some other means of preparing materials underwater $\endgroup$
    – TheDemonLord
    Commented Oct 26, 2023 at 18:52

Not the answer you're looking for? Browse other questions tagged .