I have heard this implied on this board before, that what goes on here on earth with our complex biology being the most complex thing in the universe. I don’t know if this is a question or a debate, but I do know most of the known universe is just hydrogen atoms. Are organic life and human technology the most complicated, multi layered things in the universe or are astrophysical phenomena alot more complicated than biology?
I think what you’re talking about would be addressed by “complexity theory”, but I don’t know what the answer would be.
I’d guess that you’re right about living systems being more complicated than non-living astrophysical ones. Of course, we don’t know for sure whether the only, or the most complex, living systems are the ones here on earth.
You might be interested in the Drake Equation which gives some sort of estimating capacity for the chances of life to evolve in the universe. Actually I think the equation is just meant for our galaxy. The linked Wiki article gives the current estimate for a galaxy like ours for intelligent life to evolve (a technological civilization) at 0.0000008316. Not all that high but if you consider that there are some 100 billion galaxies out there we get 83,160 technologically advanced civilzations out there somewhere.
Of course the Drake Equation is just a means for plugging in guesses but even if you plug in exceedingly conservative numbers (we know at one planet, ours, developed a technological civilization so you cannot just input zeroes) you see the chances are pretty likely that somewhere in this vast universe has evolved advanced lifeforms.
I know you are not on about a discussion on the chances of advanced life forming but this shows that it is probable it has happened somewhere else too. If you forget advanced technological civilisations and just go for life in general (plants, animals, whatever) then the chances are even greater.
So the answer to the OP is that while as far as we know we are the only life in the universe it would probably be a bad bet to think that is actually the case. We just haven’t found any other life yet but given the vast distances involved it is not surprising. Whether or not that life is more complex as a biological entity who can say? Not even sure how you would measure it.
I would also say to the OP that yes, a lifeform is a more complex entity than a star or planet if you ignore any life (if there is any) as part of that planet. If you consider the overall biosphere as part of a planet then I suppose you could consider all life as some sort of metaorganism which would be more complex than any of its pieces but that is a different discussion.