While physicists do play with the equations of closed time-like curves, ie. time travel, we don't know if it will ever be practical to travel to the past. It is possible even now in theory. By circumnavigating a black hole just outside of the event horizon, a phenomenon known as frame dragging can cause the astronaut to travel back in time to the point at which he first entered the orbit. If done just right, he could see himself entering as he leaves. But we don't have any black holes handy. But, lets say it does become possible to travel back in time like in a science fiction movie. Would you be willing to risk changing history and perhaps wiping yourself or others out of existence? How far back would you go, a day, a year, centuries, a million years? Would you support a no time-travel law banning travel to the past? Heh, the temporal prime directive...
What about going back a day to reverse disasters? For example, send someone back to prevent the shooting in Gilroy Ca?
Like i said, good intentions... who knows what else we'd screw up. Probably best not to mess with it.
Can you imagine making that argument to the families of the dead? I'm just shooting from the hip here. I'm not arguing either way but playing with the idea. Imagine the pressure that would exist to save the dead. And going how far back?
I cannot imagine having to explain that to the families either.. we are all just shooting from the hip. What i can imagine is a government agency in charge of time travel and how to use it. Who to save, who not to save. Maybe who to kill and who not to kill. That sounds scary.
Then just go back and undo that. Although, if one went back, how does one return to present? And if return to present is possible, then future should be equally possible.
I have no idea what location he was from. But he invented the T-800. Do you want to put T-800, Marx, and Lenin in a cage and see who's spleen is still intact after 30 seconds?
We would need to know a LOT more about this. If someone were to go back and change something maybe they would simply be forking off a new universe - something some theoretical physicists think may already be happening for other reasons. Maybe making a change would be somehow impossible, as the timeline already occurred. Perhaps one could see things (like your own spaceship entering the influence of the black hole in your example), but couldn't reach anything that would change that ship's course. Thus, perhaps you could go back and watch the people die again, but not be able to save them.
I would travel back to eliminate the individual who invented time travel.....which would immediately eliminate my trip to eliminate time travel.
I don't think we will.ever travel to the past. What kind of propulsion is going to get you around a black hole? Would you not be crushed? Would you not be sucked in? Does your math figure the crushing effect of gravity or the force needed to accelerate out of the event horizon? I mean could it be physically possible? I am not a physicist but I don't think so.
The big deal with time travel to the past is that you can stop yourself, or loved ones, from ever being born. Not by killing them, or interfering with past relationships, but just the act of egg meets sperm is a genetic lottery and by giving the randomness another go would change millions of people. Imagine you go to the past and then come back. Suddenly you were never born and your brothers and sisters want nothing to do with you...
And that's a paradox. How could somebody that never existed change the past? I don't believe logically that you can change the past.
