[frogeyedpeas]

Chemistry and reactions would absolutely still be a thing. Reactions happen underwater all the time such as the complex decay of organic matter.

The fire meta get's postponed until trapping air inside bags happens (could be seaweed/skin based bags).

Then you need to make a habit of collecting a bunch of air and trapping it and then can begin exploring chemical reactions in the air.

ex: take dead but not decomposed organic matter, dry it out in hot air bag (maybe cover the bag in black squid ink and float the bag of air in the ocean out in the sun's rays for day to warm it up.

Then eventually you need to have the insight to do friction based experiments in the bag with dried materials and then one discovers fire in a massive breakthrough not dissimilar to when humans created Bose Einstein Condensates for the first time in highly specialized environments.

Nothing here says "impossible" to me. I bet if whales had fingers to easily manipulate matter they might've already done all this by now.

[baranul]

While I agree that there is no logical reason that underwater organisms could not become highly intelligent or advance to the level of doing experiments with fire, it is clear that being underwater is an additional barrier.

As such, the number of intelligent underwater civilizations, that could get near our present level of advancement, would likely be significantly lower. Not impossible (because of how large the universe is), but some order of magnitude, less possible.

[rsynnott]

> While I agree that there is no logical reason that underwater organisms could not become highly intelligent or advance to the level of doing experiments with fire, it is clear that being underwater is an additional barrier.

Meanwhile, a few thousand lightyears away, some sort of talking crab is rubbishing the idea that industrial civilisation could arise on land; after all, they wouldn't even have access to hydrothermal vents! What would they do for energy, burn plants?

(I really think we're inclined to build a _lot_ of unwarranted assumptions into what industrial civilisation has to look like and how you have to get there, because it's what we did.)

[exe34]

> As such, the number of intelligent underwater civilizations, that could get near our present level of advancement, would likely be significantly lower.

Unless of course, having opposable thumbs and >50 year lifespan and intelligence in the water causes you to go through a completely different developmental path than land based creatures. We just don't know.

[LargoLasskhyfv]

Why so complicated? There could be many 'mini-labs' in underwater caves, accidental discovery of inverse diving bell so to speak. With trapped gases of any sort, by whichever process(volcanism?) pushing the water out downwards, while unable to escape upwards. Ready to explore, and mess around with. Maybe even in something like free floating coral reefs. Or below the ice.