“what conditions would a duplicate earth be created”
I would guess, because that’s all I can do, is by the
same conditions this earth was made. Even then the same
organic and inorganic compounds could be made by other
means and under different conditions like methane or
alcohol. To believe that life only exists here on Earth
alone and no where else is weak faith at best. What we see
of the universe outside of our own solar system is at
least
four years and possibly five billion years old. I’d say odds
are there are probably a million earth like planets with life
on it and most inhabited by intelligent life.
I don’t doubt that there are many planets with life. Some might well be similar to earth but not the same. Our pattern of life seems to have its basic organic compounds spread pretty wide. But for plate tectonics, we could have been a snowball without much free oxygen in the atmosphere. I think this is the sort of probability Hazen was going for. I know that he believes life is very widespread in the Universe.