Doing chemistry under water?

Question

Aquatic races are usually assumed to be stunted in technological development by the inability to create fire or forge metals.

But what about doing chemistry at all?

The development of chemistry in human history seems to hinge on being able to perform reactions in aqueous solution. That's convenient for us because water is abundant, lots of natural chemistry (including biochemistry) occurs in aqueous solution, and you can store dry materials and get them to react only when you want them to by dissolving them, or by mixing solutions that have been stored in separate containers.

Underwater, where your entire "atmosphere" is an aqueous solution, many of those conveniences go away. Storing dry materials is much harder, as is keeping pre-prepared solutions separate, as they are liable to diffuse into your equivalent of "air".

However, it seems to me that there are analogs for how we do chemistry that would work under water. After all, we can do a lot chemistry with gasses, which must be carefully stored in sealed containers lest they "dissolve" in our atmosphere. Thus, given the ability to construct suitable containers, an underwater civilization ought to be able to do chemistry with separately-stored aqueous solutions and other miscible liquids just like we do with gasses. Additionally, perhaps they could do chemical reactions in non-aqueous solution--say, by storing "dry" ingredients that get dissolved in oil bubbles to perform reactions.

So, am I on the right track there? Despite lacking access to fire, and being entirely enveloped in aqueous solution, could an underwater civilization nevertheless develop significant knowledge of chemistry and chemical engineering technologies? And if so, what might that developmental path end up looking like?

Answer 1

I think you are on the right track and this is a really fun question. I think the issues you mentioned with things like generating heat are much larger obstacles than doing chemistry in a fluid medium would be. For an aquatic-native race, anyway. I'm going to focus mostly on the last part of your question, "What would their developmental path look like?"

I think their first chemistry would be food related Without being able to salt and dry things for preservation processes like fermentation could be an early way to store and age food. It's also a heat-free alternative to cooking. Something which produces a thick mucus like a frog's egg or a kelp with non-soluble rubbery sap would probably make a thick enough barrier for your underwater kimchi to thrive. Then you start boring holes in the coral or rock to protect your food while it ages. If you're going to get pottery to work underwater without heat, you'd probably start looking for a chemical reaction to harden/cure it around then.

This is a good place to mention that if this is an alien world the flora and fauna are going to be providing a lot of inspiration to the scientists there. Clear, pressure-resistant exoskeletons on large aquatic animals could get you past early glassware, for example. It's also a good place to bring up that the aquatic race you mentioned will likely have very different physical tolerances to humans. How close can they swim to geothermal vents? Maybe heat isn't such a big problem for them after all...

Understanding and manipulating pressure, especially water pressure would be an early development By your "being entirely enveloped in aqueous solution" we're ruling the surface out entirely, so I'll go ahead and assume we're talking about an icy surfaced moon or something where there just isn't an up after a certain point. So down is the only way to go for our sea people when they want to explore new territory or follow migrating prey. They may not have to deal with breathing underwater but they will still have to withstand pressure and possibly temperature changes. They'll want technologies to help the with that.

If it were me I'd cheat and give em a pufferfish that works with a chemical reaction. Eats shells or something and combines it with acid in an organ to inflate super-rapidly, even at depth. Starts floating up like a rocket too. That gives 'em inspiration to develop gas bubble producing technology, even at low temps the gas could be harvested slowly over time. Since all you need is an upside-down vessel containment would be relatively easy so you wouldn't need a lot of complicated tech to make a glove box analogue like Dutch's answer shows.

Even without the fancy bubblefish, there'd be streams of bubbles coming out of their primitive carboys and fermenters. They could catch those. Being able to harvest and capture gas would be a HUGE leap in buoyancy control. Being able to make cargo weightless would probably be as significant to them as the wheel was to us.

With the right natural resources, a hunting society would discover toxicology early I am picturing highly-venomous sea snakes which our merfolk capture and milk by forcing their fangs into the meat of snails, then sealing the snail shell with clay. The toxin would be extracted later to facilitate hunting more formidable game. Diffusion and concentration, safe storage and handling would all be necessary studies not just to produce and use these kinds of tools but again exploration as well. Are there underwater lakes or currents saturated with heavy salts? Is there oxygen in them, or are they dead zones? They'd need ways to detect these things, ideally before swimming into them.

I'd be hoping for some form of epoxy or thermoset adhesive as a pretty early development. Once those start getting off the ground and reliable you get to composite materials (like micarta.) If you can get those composites sophisticated enough you'd find alternative solutions for most of our metal products without ever needing heat. The idea is to try to find a workaround to get our briny buddies to plastics without needing metallurgy. I suppose they do potentially have access to unlimited free pressure... They could get their plastics to set/fuse by sinking them really deep and then reeling them back in. They could use this same process for ceramics too.

Speaking of porcelain, sanitation would probably be pretty crazy for an aquatic society. Have fun figuring out how the toilets work. Here's my vote: I think there's a big room in the basement of your underwater apartment complex full of whatever gas-producing algae they're using. It's analogous to a water tower on earth, gas flows up a central tube and connects to give you "running gas" instead of "tap water." Also pulls a vacuum as it goes, if you seal it well enough and set up the right valves. So you to use the lavatory you'd flip upside-down, sit on the bubble, do your business, then flush it all out the ceiling. It would be carried out of the building on a gently sloping aeroduct to join the sewers far above the town. Eventually it would get to the wastewater treatment plant where the SERIOUS chemistry would happen.

Cause let's be real, for these folks wastewater treatment > fire. Underwater smell and taste are effectively the same sense. If you can taste your town's pollution and sewage... well, I'm guessing their perfume game would be on point and the essential oils really would be essential.

Answer 2

During my PhD years I had to work with some materials which were quite reactive: as soon as they were exposed to oxygen or water they reacted very vigorously with them, leaving the poor student with a damaged sample or, even worse, with a sample which spontaneously took fire.

A solution for handling these materials and keep the students alive was to use glove boxes

These boxes are sealed and supplied with dry nitrogen, allowing to handle materials otherwise impossible to handle in free air. There are similar concepts for handling highly radioactive materials.

Using a similar concept it is possible to carry on chemistry underwater.

But a glove box is something relatively recent, Lavoisier and all the chemists before him didn't have it.

However there are examples of reactions which happen even though the environment looks not the right one, for example the digestion of fats/oil carried out in a water solution (essentially droplet chemistry), or the existence of biological cells and all the chemical reactions they execute, which are water based solutions in a different water based solution, with a lipid membrane keeping the two separated (again droplet chemistry).

Therefore, yes, if you can manage to create and control droplets you are on the right path to run chemistry in an underwater environment, until you are able to build something like gloveboxes.

Answer 3

The ease with which information could be obtained would depend on the details of the environment and might be seriously limited. The “easiest” situation would be a civilization based in a shallow sea with access to the materials of the coast and access to the surface. Harder would be a civilization based in a deep sea far from land. And the hardest would be a civilization operating at great depth with no access to the surface or the seabed.

At issue would be the availability of material substances to experiment with, suitable support structures and access to a phase boundary (liquid solid – the seabed or liquid gas – the surface).

One big unknown is the level of technology. As the development of chemistry and technology are intimately linked, it is hard to know where to start. But that starting point would probably not be similar to ours. One of the first human technologies was fire that would not be the case with an aquatic civilization.

Given technology such as glass bottles, electric pumps and such like it would be relatively easy to do all manner of experiments under water. But the problem is glass bottles and electric pumps would themselves be difficult to invent underwater without access to high levels of heat. And the high levels of heat available under water such as from volcanism would probably cook anything that got too close.

They might well learn a good deal of physical chemistry from the way gases in bladders behaved at different depths but without appropriate containment vessels it would be extremely difficult. If technology is assumed then it’s possible but that would in a way be cheating as they wouldn’t have that technology.

Answer 4

OK, slightly left field answer to this one. Assuming you are in an equivalent ocean to Earth's, you're never going to need to do your chemistry purely underwater.

You have a water surface, you have underwater vents, fish have swim bladders etc. If you are careful you can "harvest" these, with anything waterproof (intestines, etc). You may even be able to find "gas filled" caves, though you may struggle to maintain any gas ratios without a fair bit of work.

Answer 5

Above the surface, we contain liquids and solids in concave vessels, openings pointed up, and tilt them to pour contents.

Below the surface, you can contain gases in concave vessels, openings pointed down, and tilt them to pour contents (at least for non-water-soluble gases; wouldn't work well at all for ammonia, hydrogen halides, or hydrogen sulfide/sulfur oxides).

But you can also drive water out of such a vessel by displacing it with gas. Maintaining a gas-filled environment like that is probably easier than maintaining a vacuum environment on Earth's surface, because there's no pressure differential fighting to overcome it.

The big catch is going to be heat, though. Nearly every part of chemistry involves adding heat to substances or removing heat from them, and since water transfers heat much more effectively than air (through conduction, convection, and even vaporization/condensation), thermal management will be a lot more work than it is for us surface-dwellers. Also, fire is a super-convenient heat source, and it's essentially unavailable underwater. Maybe the alchemist class builds their laboratories around thermal vents in the ocean floor...?