Why do we remember the past but not the future? Why is it that we can decide what to do tomorrow but not what we did yesterday? Theoretical physicist Carlo Rovelli revels in asking such questions about the nature of time — they might seem trivial at first but they force one to look deeper, revealing new aspects of reality. He has been pursuing answers to questions like these for years, and eventually, came across work by SFI Professor David Wolpert on how time works in different memory sys...