okay, david brins book 'existence' does a complete number on me, a man who put me off reading his work after seeing the awful movie version of 'postman' with kevin costner. i just put him on the ever increasing pile of terrible science fiction writers and i think i made a mistake.
approaching 'existence' with this type of mindset was unhealthy, i slugged away through the various narratives until about a third of the way through, i liked some of the ideas and scenarios imagined, there were some brilliant ideas in there. slowly i cracked the mindset and broke through, discovering a rich tapestry of ideas and creativity. each page reveals some new future, on an earth post apocalypse, where things were nowhere near as bad as we imagined an apocalypse could be, brin throws in a fist contact idea. 
i like the imaginary books excerpts brin uses as a thread, the way an autistic plague has effected millions of individuals, the way dolphins teach humans to speak dolphin by rewarding them with fish, the way events are hinted at but never revealed, the science fiction genre is all about ideas and 'existence' is jam packed loaded with ideas.
at it's core is the discovery of space junk and debris collector gerald who discovers the object, an orb like crystal containing the uploaded consciousness of extra terrestrial intelligence, and it communicates the words, 'JOIN US.'
while at the same time in the submerged and flooded environments of shanghi a young man peng xiang bin finds a second orb that claims the first orb inhabitants are 'LIARS'
in between the narratives are the many diverse characters and threads that may or may not come together, it really is a collection of ideas, some of which cancel others out, it's a highly intelligent and literate book and i have to confess has me curious about his other novels. the novel converges about two thirds of the way through but like all great things it is the journy not the destination, and despite the bumpy start, it's smooth running all the way to the end. a great novel indeed.