I like the Rare Earth theory. Nick Lane, who is largely responsible for the life reactor at UCL, says in "The Vital Question: Why Is Life The Way It Is?" that any complex life on Earth already went through an extremely unlikely bottleneck and somehow came out the other side successfully.
,
Once.
,
In 4.55 billion years.
,
Our Last Universal Common Ancestor incorporated a random proto-cyanobacteria (which eventually became mitochondria) that accidentally turbocharged her internal mechanics and stepped up her energy output by orders of magnitude. Bacteria and things like it will probably be relatively common throughout the universe, but that extra giant metabolic kick to open the door to a possibility of complex life that opens the door to a possibility of sentient life is going to be vanishingly small. It might have only happened on Earth.
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I hope it didn't only happen here and we aren't alone in the universe. But Dr Lane's theory is a pretty solid argument that we could be.
I think it’s likely a combination of these and other theories- when you add up all the variables- the odds that life as we recognize it would emerge and survive- be close enough for us to even detect, that in all the vastness of space we would find that needle in the haystack- that said life had survived all the events required to get to this point, that it is recognizable and follows our same technological path and evolution, AND that we exist at the same time?
Very slim odds indeed. The theory this leaves off but is related to the young earth- is that in the vastness of space- life could have flitted in and out of existence a number of times already. Add the distances we are talking about and the time it takes for signals or light to travel those distances- well... if we were looking at a society just like us 100k light years away through a telescope- by the time we are detecting them... they may we’ll be extinct.
A theory this touched on but didn’t really get into us one which states we may have already found “extraterrestrial life” and even if we were staring right at it- we wouldn’t recognize it as life- possibly wouldn’t even see it. The mind is an odd thing- but optical illusions and all sorts of phenomena revolve around the fact that the mind sometimes doesn’t know what to do with what it is seeing- and in some cases- that thing is so foreign to the mind that it just... blorpz. Maybe you see something your brain just picks at random but you know- maybe you see nothing because that thing doesn’t look “important” to you so you just don’t notice it.
It seems a strange notion- but we only can really picture life on earth. What else is there- if it isn’t a fungus or a plant or insect or mammal etc etc? How do we picture the thing we’ve never seen? We can imagine- but I’m old. I’ve seen- not what fiction writers have come up with- but decades back on what actual accredited professionals hypothesized was the likely course of biology on foreign worlds and... we haven’t found anything to prove or disprove them- but their interpretations are largely seen as and held as quite silly when viewed from the future.
But it doesn’t have to be so “new age” as all that about perceptions or dimensions of existence- does an electronic consciousness really NEED a physical form? Do they NEED stain spheres? Perhaps they transbiokigically or by virtue of their creation- exist without a form as we might know it.
Why would you spend eons and engineer ways to warp the physics of our world against its will when- in theory- long before you’d reach “dyson sphere” you would probably find a way which would allow you to exist... let’s say for ease of language and try not to eye roll the cliche- as a “digital consciousness”? Assuming you had some way to ensure what you considered an acceptable longevity for this digital collective- or even that you could use a star or planet or the universe as the “hardware” to run this on- it seems like that would be the place to go. Unless you had illusions about eternity I don’t suppose you’d much worry about equipment failure either even if you knew your little world could “only” last a million years or until your planet were destroyed.
Statistically I think there is likely life somewhere in the universe- if not now- before. If not before- someday. Panspermia has been rejected more or less in serious science- both as a source of life on earth but also as a potential future for it or method to spread life to other worlds someday accidentally... but who knows? Perhaps something on one of our missions- or a future mission- finds a way to survive on mars and the life we find someday is life we put there? It’s all academic. Your odds of meeting an alien and realizing you met one are pretty slim regardless.
,
Once.
,
In 4.55 billion years.
,
Our Last Universal Common Ancestor incorporated a random proto-cyanobacteria (which eventually became mitochondria) that accidentally turbocharged her internal mechanics and stepped up her energy output by orders of magnitude. Bacteria and things like it will probably be relatively common throughout the universe, but that extra giant metabolic kick to open the door to a possibility of complex life that opens the door to a possibility of sentient life is going to be vanishingly small. It might have only happened on Earth.
,
I hope it didn't only happen here and we aren't alone in the universe. But Dr Lane's theory is a pretty solid argument that we could be.