Diaspora

 Three types of humans exist: digitalized, cyborgs and dna-enhanced. The protagonists are digitalized and one is actually constructed as a digital being. They become a bit friendly with some humans. Cyborgs realize though that stars have clashed with each others and the shock-wave will decimate the humans. This astronomical events go against their knowledge of the universe, so starts a quest to find out what happens. Our digitalized minds go on planets constructed to have messages in atoms, and they jump through universes with different dimensions. 

Crazy dense