Is time travel into the past theoretically possible? If one could could travel into the past, would dead people exist again?
If we could travel back into time, could we meet people who have died? Would the dead exist again?
How long would it take for all traces of humanity to disappear if we all died tomorrow? If I went back in time and killed myself, what would happen? What would the world be like if we no longer could die? What would happen if you traveled forward in time to the date of your own death? Is it possible to communicate with the dead? If every human were to suddenly drop dead, how long would it take for all traces of humanity to go away? What would've happened if humans were immortal? If we die and come back to life how will we know? What would happen if humans were immortal? Can we bring life into a dead body? If I went back in time, and was killed, would I create a time loop? Can people really speak to the dead? How can we talk with dead people? Is that possible? If I went back in time and was killed would I create a time loop? Is there life after death? Can we revive our life once again as next avatar of ourselves? Did ancient people have similar inherent longevity to us, but we're just killed off sooner by violence and disease? If we are all going to die eventually. What's the point? Where will we go after our death? Can humans will themselves to die? What would happen if you went back in time and killed your grandfather? If humanity disappeared right now, how much time would it take for every evidence of our existence to disappear from the face of the Earth? How would humans behave if we were immortal? If there was prof of reincarnation. Would people kill themselves in hopes of starting a better life? "a kinda start over button" Do we live to die? If humans stopped reproducing, what would the chain of events be, from now to the death of the last person?  What if I went back in time and killed my past self? Are human beings destined to go extinct? Can we survive death? How populated would our world be if nobody had ever died? Are we actually immortal?