I've been thinking of this. Anyway my idea is that when you time travel either to the past or to the future you would be outside of the timeline. Meaning even if you kill your grandfather you would still exist but it would remove the existence of your father and the other you who is still in the timeline. For example if you cut a piece of cloth (A) , the clothe that I cut will not be part of the other clothe (A) anymore. So even if you burn the other clothe (A), the clothe (B) would still exist because its separated therefore it would not be burn. That would also mean that you can change the past.
Any thoughts and suggestions to my idea?
Update:@RockDude
Who said you need to travel in the speed of light? If you look at the UFOs for some reason they are able to disappear instantly within seconds. They also seem to be able to bend gravity. I wouldn't be surprise if they are actually a time machine, considering how they always seen to avoid us.
Update 3:@goring
You said "difficult" not impossible therefore it still is possible.
Update 5:@OldPilot
That isn't really what I mean. It's still our timeline and it still is our grandfather and our father and mother. Changing the past or the future means your unaffected because your already outside of the timeline. It still is the timeline but It has changed.
Answers & Comments
Verified answer
The issue with your theory is that it results in a logical impossibility. If you kill your grandfather, you acknowledge that you remove your father and your previous self out of the timeline, but you still remain. Where, then, did you come from? If your model was correct, it would result in violations of energy and mass conservation, which modern physics currently believes to be inviolate (and no evidence to the contrary has been found).
Right now, the current physical understanding is that time travel into the past is impossible, removing the issue altogether.
Time Travel to the future is possible by application of Special Relativity (Near light speeds) or General Relativity (High gravity fields). The science for both is solid, the engineering will take some work.
Time Travel to the past is more difficult. The Arrow of Time points from past to future. What drives it in that direction is the 2nd Law of Thermodynamics, the total entropy of the universe is increasing. This, means to travel to the past would require the input of enough energy today to reduce the entropy of the universe to the entropy of yesterday, a huge energy requirement with a hook. That increases the entropy of today making the universe one day older which moves you one day into the future to go one day to the past which means you don't go anywhere.
Getting past that problem, there are 2 possibilities:
We have no Free Will, every thing is fixed and we cannot change it. The Grandfather Paradox is not a paradox because every time we try to kill our grandfather we fail, the gun mis-fires (See Quantum Suicide/Immortality).
or
As you say, we change time lines ====> Our grandfather is not our grandfather (grandma had an affair) or our farther is not our father (Mom had an affair or was raped) or you were adopted and no one told you.
Basically you are talking about time streams, even if one make changes in one time stream isn't affected,, well it may be possible, but I really don't know. I mean, theoritically you could time travel in future if you can move near the velocity of time, but travelling in past, Don't think its possible
It would be absurd to think that time can be changed. Because by definition time only indicates the past. and you cannot return in the past to reconstruct it. If you drop a cup on the floor and it breaks in one thousand pieces it Would be difficult to return it to its original condition.
First of all time travel is not possible For humans under any circumstances, because you would have to be traveling at the speed of light or faster to travel through time. Since you are not light, you my friend can travel through time.
Make time travel possible before asking this question dude.
confusing aahaha