A lot of terran animals are intelligent. And many of those are sentient. Think elephants, dolphins, nonhuman apes, dogs. We do not know if and how many of the dinos were sentient, but I would not be surprised if many of them were.
So extraterrestrial intelligent and sentient life? Quite likely and I would say, inevitable.
What you mean though is technologically minded life forms. For that, you have to realise that there have been several different species of humans besides homo sapiens sapiens in the past.
Again, we do not know if any of the dinosaurs were technologically capable, but time has a way to wipe away traces, so we will never know, but based on what we do know is that techno species will only arise if the evolutionary pressure pushes them in that direction, which is almost never the case.

Space has nothing but time to develop such things.
Life evolved here in at least 2 (I think I read 3) completely different ways. Our DNA has commonalities with dogs, birds, zebras, etc., but Jelly Fish DNA is completely different. That would indicate that, under the right circumstances, life can “find a way”.

@ragingloli Why would you say that evolutionary pressure does not often move toward technological capacity? Doesn’t it seem that all the most intelligent life forms on earth are already beginning to use rudimentary tools?

@filmfann Excellent point.

At least once, evidently. I don’t think we have any means of determining the actual probability of it occurring.

@ETpro
Because most of the time they are surviving just fine without it or with just rudimentary forms. Evolution works on a “that will do” basis.

I think it is very unlikely that life would not exist in other places, but with the size of the universe it is a challenge to find it.

Considering modern man has only been on the scene for about 10,000 years, well…seems pretty reflective of our current LACK of evolutionary development. 2 billion years to arrive at THIS level of development? What a joke! haha
I sure hope there are more advanced life forms out there somewhere!

Our greatest “advancements” have come from carving arrowheads to Bushmaster 223’s and nuclear weapons in a short few thousand years. We certainly are going to be the species that self extincts the quickest of any ever, in the history of the universe.
The planet would have been much better off if us little Mud Puppies never took that first little excursion out of the primordial puddle. lol

@Coloma
There have been several global mass extinction events that reset the game each time, the last one 64 million years ago.

I’ve yet to see any convincing signs of intelligent life (on a large scale) on this planet… I can’t even begin to imagine if the pattern would repeat itself somewhere else.

I agree with @filmfann , aside from the fact that throughout the universe the building blocks of life would be the same, I also think that life would “find a way”....if you watch videos of deep sea creatures, they are aliens. Their bodies work in ways that are unimagineable to us….some of them never see light. Or they make their own. To me, those things are aliens. Just cause they are on our same planet means nothing to me. So I believe 100% there is life somewhere, and I hope for the sake of the universe it is nothing like human life, cause we suck. But it’s something.

@ragingloli I know, I meant that in the last 10,000 years, man has only “advanced” from being a dirt bag primitive to being a showered and shaved primitive.
We’re certainly overdue for another mass extinction. The gap needs to narrow at this juncture. lol

@Coloma
Again, technological evolution, too, only works on a “that will do” basis. That is why the really big leaps in technology only occured during war times, where the “enemy’s” intent to kill you made a pretty strong environmental pressure for improvement. Or take consumer products. The improvements are just good enough to make you buy the new version. That is why, for example, every iphone is almost identical to the prior model.

Does it matter? Would it be possible to determine they are there? Could we get a detectable signal from them? The distances involved make travel between the solar systems extremely unlikely. If we can not communicate and can not detect them, then their existence is moot.