Greg Egan 
Axiomatic [EPUB ebook] 

THE HUNDRED LIGHT YEAR DIARY — Scientists can bounce messages from the future back to the present, but there’s no guarantee they’ll tell the truth … LEARNING TO BE ME — Crystalline minds may take the place of human brains, but where does the self really lie?CLOSER — Lovers exchange bodies and minds, but their experiments go just that little bit too far, proving that you can have too much of a good thing