You're right. Absolutely, completely correct. There's almost certainly other ways life can start. Other processes that can result in intelligence. Other paths of technological development.
The issue, as I understand is, is that all of those are completely unknown. We have absolutely no useful idea of how to look for wildly different life in places we haven't thought to look.
What we do know with certainty is that Earth's chemistry can result in life. We do know that it can result in intelligence. We do know what paths our technological development took. We even have some idea what these things might look like from afar. All together, we have exactly one data point that lets us search for similar data points.
Are there other, different world, with different life? Very possibly. We humans are well aware of this. We just don't have a way of knowing if we've found anything. So as a matter of managing limited resources, there's a tendency to stick to what we know can work.
It may just be a failure of the imagination, but on the face of it the only chemistry that could feasibly make organisms is organic chemistry. That's not because it's Earth's chemistry, but because carbon is a very useful lego brick. This leaves us looking for alternatives beyond chemistry, something like Douglas Adams's "sentient shade of blue", except imaginable and not nonsense. So your certainty about this is ... staunch, let's say.
I'm doing my best to tell this user that their imagination is possibly on to something, but mostly this is a waste of energy. I'm exaggerating the realistic possibilities to help them feel good about themselves because it makes it easier to sneak in the idea that this is not a useful or productive line of thought.
The approach of "Smart people have thought of that, there are very few chemically useful alternatives" is the kind of thing that entrenches a person in their insistence that this is just a wide-scale failure of imagination. Witness their comment about "earthlike biology perspective". They want to believe a wider, weirder universe is possible. As a rule, it helps people feel heard to tell them they're right about something.
So yes. I'm going to present it as a staunch certainty that something else is possible but currently unknowable, invisible, and irrelevant. I'm doing this in the hopes that the message gets through that this is not simply parochialist arrogance at work, from which they might nobly dissent.
>but on the face of it the only chemistry that could feasibly make organisms is organic chemistry.
First order life, but what about second order?
If I make a complex 'mechano-computer' that can reproduce itself, how exactly is that different from life? Now it looks like the universe doesn't have any direct way to go to silicon based life, but indirection over carbon based life first seems very possible.
You're right. Absolutely, completely correct. There's almost certainly other ways life can start. Other processes that can result in intelligence. Other paths of technological development.
The issue, as I understand is, is that all of those are completely unknown. We have absolutely no useful idea of how to look for wildly different life in places we haven't thought to look.
What we do know with certainty is that Earth's chemistry can result in life. We do know that it can result in intelligence. We do know what paths our technological development took. We even have some idea what these things might look like from afar. All together, we have exactly one data point that lets us search for similar data points.
Are there other, different world, with different life? Very possibly. We humans are well aware of this. We just don't have a way of knowing if we've found anything. So as a matter of managing limited resources, there's a tendency to stick to what we know can work.