According to this book, our current models predict that time travel to the past is theoretically possible, but not practical enough to allow for that. You can’t go back further than the spacetime configuration that allows for travel back in time has existed.
Right, the we’re-not-already-dead argument doesn’t rule out time travel that requires a time machine at the receiving end like a telephone. But you still can’t save anyone that died before the first time machine was built.
According to this book, our current models predict that time travel to the past is theoretically possible, but not practical enough to allow for that. You can’t go back further than the spacetime configuration that allows for travel back in time has existed.
Right, the we’re-not-already-dead argument doesn’t rule out time travel that requires a time machine at the receiving end like a telephone. But you still can’t save anyone that died before the first time machine was built.