If a man from point A travels backwards in time to point B and changes an event, how does it affect history?

Question

Assuming that time travel IS possible. Do his changes change history between point B and point A, or only from point A onwards, and would everyone have recollection of the two different histories?

Answer 1

Well this one is interesting. Mathematics tell us that to move in time, one must move faster than the speed of light. There are particles that do move that fast so it is theoretically possible.

With that having been said, I'll go back to the particles that move faster than light. These particles cannot be seen or measured in any way that we can figure out but we know that they exist because of the reaction of other things. ( its like the wind blowing, you dont see it but trees and stuff react to it )

One theory suggests that if we do manage to travel back in time, we wont be able to interact with it at all. ( I dont understand all the mechanics on this one) But it would be like being an invisible ghost. You could observe things and events but couldnt make actual physical contact with anything thus you couldnt change events.

Answer 2

It depends on which theory you follow. That is, first of all, do you believe history can be changed? If you don't, then that's that. If you do, then you need to find out what you meant by change, in that it changes from the one you know, or it changes TO the one you know. In addition, is it you who travelled backwards in time, or did time travel backwards, yet leaving you exactly as you were?

To address your question, up to point B everything would be the same, assuming the person remained undiscovered. From point B onwards, his actions will result in an reaction, and hence history would change with the action.

Then, using the other point of view, person does not belong in that history (at point B), and that his presence there is abnormal, and his actions are not initially recognised from point A. Therefore, because time did not travel backwards, but only him, his actions would then alter the history you know, as he mutates the time line.

But that is assuming time is linear, and also that his actions aren't originally going to happen anyway (relative to point A). It gets real confusing afterwards, with further theories.

Answer 3

A lot of people seem very sure time travel is impossible.
Let's assume it is for a moment: what would you need?
You'd need a way/door from your present, a passage to move along, a way/door in the past.
Clearly you have to build the target door which will be in the past before you can build the entrance in the future.
If we built a 'target door', that target door would be as far back as someone after that could travel. We may well have someone step through it as soon as it was complete.
But until we have the technology to build such a door for future time travellers from even further in the future to step through we won't see any time travellers.

Clearly, time travel into the future is possible. Travel fast enough and your time slows so you move into someone Else's future more rapidly.
However, this causes an interesting problem. 'Now' from the point of view of all points in the universe is the same instant. But the speeding traveller's now would be in my future.
Therefore my future must already be there.
Which, of course, implies every event is set in stone and the freedom of choice we humans think we possess is an illusion.

Answer 4

This is the old time travelling conundrum- can I change the past and make a new future?

Some people reckon that at every decision the time flow bifurcates, leading off into a parallel universe where things did 'go the other way'... if you look at it from that perspective, then changing an event at point B will shift time on towards a new point, C. Point A would still exist, it would just be in a different stream of time.

I prefer to think of it in this way however- the present is set. Even if people go back into the past, whatever actions they take will only lead back to the present A. In other words, you could travel back in time to assassinate Hitler (for example!), but you'd just find yourself entering history as one of the people who got caught trying to assassinate him, or whatever. Time travel backwards has already happened, and the present world already accounts for it.

Travelling back to point B and making a change will still lead to point A in my way of thinking. If you really dislike what was going on at point B in time, you'd be a lot better paying attention to what's going on at point A where you are to make sure that events like those at point B don't re-occur :)

Answer 5

Time travel is impossible. We are composed of physical time and cannot violate our own existence. I expect, because it seems so real when depicted on t.v. that it seems as though it could become reality. This particular concept, though, is physically impossible for mankind to execute. It is similar to making a perpetual motion machine that would generate forever more energy than what took to make it operate.

In order to make a real time change, a person must be in at least two different places in the same instant. Just considering time travel within our history, where was our planet in the universe a thousand years ago? If you wish to move into the past you would have to be where it was at that time. Where was it, and how would you find it? What would happen if you were to suddenly pop up where the sun was, or if you were to appear deep within our own planet?

Mankind has done a lot that past generations have considered impossible. Time travel is one that shall always exist as being one of them. God would not let mankind mess with history. Can you imagine what would happen if He did?

Answer 6

If you watch Back to the Future 1,2 and 3 and also Blackadder Back and Forth in time ( I think!), then history is changed from B onwards and everyone remembers that version as history (NOT the original). I know they are only films but they do demonstrate the point (and Michael J Fox is quite cute, shame he has been struck down with Parkinsons, also some quality music!).

Answer 7

The timeline would go off in a tangent to point C an alternate present. The residents of point C will have no knowledge of point A, but may theorise what could have happened if the event at point B didn't occur e.g say someone went back in time and killed Hitler before he rose to power. WW2 against the axis doesn't occur. Perhaps the Russians develop their war machine unchecked and invade europe, causing an alternate WW2. In this alternate WW2 the germans would be allies of the British, and Hitler would be another average joe name in Germany with no images of an angry moustached man.

Answer 8

Actually this is point B. I've come back from point A in the future to tell you that you have already given me 10 points, and to persuade you to do it again. Now I plan to test your two hypotheses. If I end up with 20 points we'll know that 2 histories are possible. If only 10, then I have effaced history from point A to B!

Answer 9

Either the change would take place and he would return to an alternate future, as he knows there was a change. Or something would happen to "miraculously" stop the change even taking place. Such an event it is postulated would either prove whther fate exists or not. In the event of the change being made, then it would also prove the existence of a parallel universe. Noone would have any memory about the change, I am unsure if the person who alters the past would even remember.

Answer 10

Assuming it is possible:

History changes from point B to infinity. See 'Chaos Theory'. History would still be only one history, with only one recollection for the masses. The only exception to this would be the time traveler.

Having said that.....

I am certainly convinced that time travel is not possible. I believe this was DISTINCTLY PROVEN in Napoleon Dynamite to be a scam.

Answer 11

History, present and future would change from point B. If something was changed it would have a knock on effect and ripple outwards to alter other things. It would not stop at point A because the changes would affect what had happened in the past which would change the present... if you see what I mean!