3
$\begingroup$

In another post on this brilliant site I saw someone suggest that an aquatic species could make insulated tubes filled with seawater to transmit electricity, with the only downside being that seawater is ~10million times less conductive than gold. I really loved the theme and uniqueness of the idea so I thought how could it be made more effective?

So my question is thus: would dissolving minerals (not necessarily gold, I only used that as an example) of some kind into contained seawater improve its conductivity? In the same way that the solution of salt in seawater already increases its conductivity roughly a million times when compared to fresh water.

If this is possible, how would a species go about dissolving the mineral?

What mineral would be the most effective for the job?

In fact, would simply increases the salt solution noticeably alter conductivity and if so, how much?

And how effective could these methods get when compared to conventional gold, copper or silver wire?

This method of "wiring" needs to be at least conductive enough for the electrical demands involved with computers. Size is not a concern, the species will either use very large computers or I will just handwave them having shrunk the technology to an incredible degree, I am after all writing a fictional work not a scientific paper. Assume that the aquatic species to have manipulative ability akin to human hands and that they have access to all the resources of earth's oceans. Please do not suggest obvious alternatives such as "they could just extrude some copper into wire" as, while true, I am obviously trying to worldbuild an interesting and unique setting with differing technology to ours, I am not trying to adapt human techniques to an underwater setting. Even if they are the most effective. Other than that feel free to suggest other alternative ideas for electrical conduction that fit the theme.

Thanks in advance,

-FrankRebin

P.S. I understand that I have asked a series of successive questions in the body of the question but I see them as elaborations and sub-questions in the hope of getting a more thorough answer to my overarching query. I also don't want to needlessly bombard the WorldbuildingSE with a bunch of incredibly similar separate posts, so I hope my inclusion of several queries in the body of my question meets with admin approval. :)

$\endgroup$
3
  • 1
    $\begingroup$ Do they need to conduct electricity from a central source? That will be tough given resistance. What about an alternative where they get power by harnessing living creatures as local/hyperlocal sources of energy. Computers/lights each powered by mutated integrated living bio electric plants/creatures Where the creature itself grows to form the required connections? $\endgroup$
    – JonSG
    Jul 23 at 15:51
  • 1
    $\begingroup$ Doubtful, see quora.com/… . In particular, since conduction is ionic instead of metallic, "One meter of seawater has the same resistance as 7,000 kilometres of Aluminium Conductor Steel Reinforced Cable." (and based on charts, increasing the salt concentration doesn't help that much) plus "if the voltage is too high you'll start electrolysing either the salt or the water depending on which salt you use." $\endgroup$ Jul 23 at 15:57
  • $\begingroup$ Unfortunatly not a great idea, but to maximise conductivity an obivious choice is have more of already present salt, to the max. You state that u do not wish to adapt present tech solutions, but it is what you do here, with water conductors. It can be a solution they started(not for everytijng), until a better alternative which will happen if they get to the point of computers and stuff. $\endgroup$
    – MolbOrg
    Jul 23 at 16:03
6
$\begingroup$

Sea water is already a pretty good conductor -- good enough that you need to keep it out of even low voltage electrical equipment to prevent shorting out. The linked article suggests that the lowest the conductivity gets is about 3 S/m (3 Seimens is 1/3 ohm). That level of conductivity is a little low for high current, but you won't improve it much by increasing the dissolved minerals in the water; even when saturated, conductivity is only several times this value (by contrast, the conductivity of pure aluminum, used for most outdoor power transmission installed in this century, is about 39 million Siemens per meter).

$\endgroup$
3
  • $\begingroup$ Thankyou for your informative answer! If no further answers appear in the next 24hrs, I will accept this one. "even when saturated, conductivity is only several times this value" is all I needed to read to understand my proposed idea is totally unfeasible. Does that quote specifically include changing the dissolved mineral? i.e. dissolving aluminium into the water. Or does it just refer to increasing the salt content? $\endgroup$
    – FrankRebin
    Jul 23 at 16:10
  • 1
    $\begingroup$ As I understand it, only total dissolved ion amount (i.e. molar concentration) contributed to conductivity, not species of ion. This is because the ions themselves are carrying the current, not free electrons as would be the case in a metal. $\endgroup$
    – Zeiss Ikon
    Jul 23 at 16:16
  • 1
    $\begingroup$ @FrankRebin 30million times difference is not necessarly a bust, because it translates in "just" 5000 times thicker, so 1mm wire converts to a 5m one, sure inconvinient for everything, but not impossible. In general tech for aquatic ppl is not impossible, just keep those for very very ancient (local equivalent of pyramids and older) buiildings and in museums - look that was first electrical conductor used a million years ago(equivalent for first fire or something along the line for humans) $\endgroup$
    – MolbOrg
    Jul 23 at 16:27
2
$\begingroup$

For power purposes, @MolbOrg's comment hits on it -- you can compensate for lower conductivity by just imagining very thick conductors. This isn't as bad as it sounds since the 'material' of the conductor is just the seawater you're living in (so no cost). The cost would be the insulator around the seawater.

You can imagine that within buildings there are insulated ducts meant to carry electricity. Between buildings you can imagine some sort of sewer-like system for electricity.

But OP mentions computers.

For computing purposes, it's not just about conductors. Modern computing needs semiconductors. Seawater won't work at all. Older computers used vacuum tubes or relays, instead of semiconductors. But those still involve metals.

On the other hand, you could skip electricity entirely and use fluidics, where computation is performed directly by fluids.

In fact, some of these were built in the real world. Wikipedia describes MONIAC thus:

The MONIAC was approximately 2 m high, 1.2 m wide and almost 1 m deep, and consisted of a series of transparent plastic tanks and pipes which were fastened to a wooden board. Each tank represented some aspect of the UK national economy and the flow of money around the economy was illustrated by coloured water .... At the time that MONIAC was created, electronic digital computers that could run complex economic simulations were unavailable.

$\endgroup$
1
  • 1
    $\begingroup$ I certainly like the idea of analogue computers and have in fact already included them in the setting, partly involving fluidics :D Thank you for your answer! $\endgroup$
    – FrankRebin
    Jul 23 at 21:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.