Well, I've been trying to look into this, although I'm hampered by my lack
of expertise in astrophysics. The Solar system formed about five billion
years ago. One of the reasons that life could form here is that the cloud
from which it formed was already enriched with oxygen and carbon. The Big
Bang (if that's what happened) produced only hydrogen and helium, and
happened only some seven to thirteen billion years before the formation of
the Solar system. It would take a certain amount of time for enough large
stars to form and go supernova to enrich the interstellar clouds of our
galaxy with the oxygen and carbon that were available at the time the Solar
system formed. When I try to answer the question "How much time at a
minimum would be required to form and disperse the necessary amount of
heavier elements?" I find I get led into astrophysics textbooks and papers
that are too hairy for me to understand without devoting a lot of time to
it, and they don't present "the Answer" to this question in the abstracts
or conclusions from which a layperson could easily grab it. So to me, it
seems like an open queston. If anyone can close it for me, I'd appreciate
it.
In the meantime, though, it seems entirely possible to me that we just
happen to be the first on the block, and that's my hypothesis (shared by
several others, some of whom suggested it to me) about Fermi's Paradox.
-- Eric Watt Forste ++ Q: What is the meaning of life? ++ A: You're soaking in it!