Well, deep sea, thermal vent life is predominantly blind on earth at least. One may postulate this form of life is much less likely to form technological civilizations thus moderating such. Thoughts?
These are separate variables in the equation. The drake equation multiplies a bunch of probabilities together, one of which is "probability of planet having life" and another is "probability of life becoming technologically sophisticated". A the moment we don't really understand how life starts, so it could be really really unlikely or it could be pretty common. finding independent life events in our solar system means it's pretty common (otherwise it could be 0.00001%).
Consider the way such life looks to us. It's stuck down there, hampered by its environment. We might look that way to an advanced civilization. "Check out those humans, they're intelligent but they're stuck way down there on the crust of that planet, under all that air, stuck in their gravity well"
That's very true, if earths Gravity was just a bit stronger chemical rockets couldn't even make it to orbit. Like right now we can only get 5 to 10 percent of vehicle mass to orbit, imagine if that where 1 or .001 percent. That would make space exploration incredibly expensive. It's already prohibitive at our level of gravity.
So-- there are caveats. A lot of deep sea life are able to see, and it's because deep sea life also generates their own light. It's a way to communicate to mates, and a way to notice prey, and a way to bait smaller predators.
I also think that echolocation has potential to be equal or better to eyesight! Bats and dolphins do great with it, and I think that it's easy to think of echolocation as being a _visual_ stimuli, even though it's not lightwave-based.
I think the biggest hurdle for an underwater sentient species trying to become more advanced is the difficulties with tool-building. Simple stone tools could be made, but it becomes a lot harder to smelt iron and start doing metal-working.
I was thinking very same issue for some time. Underwater species will have limitation to advance their Intelligence due to not having access to LAND to make all kind of TOOLS which led to Human Spices advancement .
It seems we have a kind of proof at this time planet Earth.
'Long-finned pilot whale' have '37 Billion' Cerebral cortex Neurons , where as Human Spices have 21 Billion .
I think due to their Water environment WHALE did not become the dominant spices on EARTH but Humans became .
By the way, the all-caps in your message makes your post kind of confusing, and it almost sounds sarcastic? I'm just letting you know in case English isn't your first language. :)
Yeah the sea surface is a glacier. There might be air pockets though? But it would also be near-freezing there, whereas the core would be much warmer, and would also have more pressure.
Here's the full equation: https://en.wikipedia.org/wiki/Drake_equation