[Audiobook] Ripples in the Chronostream, Ten Theoretical Pathways to Times Embrace (Perhaps) by Lucan Merrian.
This book is a whistlestop tour of some of the actual theoretical physics that opens the door to travel through time. There are ten theories described here, most of which rely on exotic matter, which we have yet to encounter in our universe.
Most of these theories ‘revolve’ around spinning things, one way or another, with various constraints and handwaving at the limits and edge conditions.
This book is talking about the kind of physics that got so pilloried in A Fools Wisdom, things which are so fantastical that they require infinity to be a practical unit of existence rather than something beyond our comprehension.
I was disappointed by the brevity of the book, ten theories in a hundred minutes doesn’t give a lot of depth on any, and the practical applicability of the theories leaves much to be desired. If you are struggling for a starting point in your time travel research, this might be a good place. Blueprints for a tardis this is not.