Time Travel and Changing the Past

If traveling to and interacting or communicating with the past is really possible then doing so could also mean that past history could be altered, even when no changes are intended. Any change in past history could lead to a chain of related events that cannot be predicted, and possibly have dramatic consequences. Could there be any reason to justify an intent to change our own past? The dangers are so obvious that It seems unbelievable that anybody would ever be willing to take such risk. What could we actually achieve by changing the known history time line and why would we ever try to do such thing? Would it not be much better to leave the past alone and just learn from it.

Reasons why consider changing the past

• All action no brain - Are you unhappy with certain events? Just jump back and change them! And suddenly 911, the war in Afghanistan and Iraq never really happened, Sadam Hussein and Bill Laden were never born. If it would be that simply.... Removing events will cause other events to take place, and could lead to a chain of events that might be even more destructive. An alternative history might not even have humanity in it.
  
  
• By mistake - What does this button do - oops. As the result of some kind of mistake we could be responsible for many of the mysterious events that took place in the past, without being aware of it. Future experimenting might unintentionally cause the creation of prophecies in the past: The oops syndrome.
  
  
• Ignorance - Thinking that experimenting with time travel technology cannot really cause changes in our own history time line. And if it does, then you can easily get away with it as nobody will notice . Further to that, possible consequences of time travel experiments are explainable in other terms as well and will not be linked to future science experiments. Do we know of any events in history that we clearly recognize as a future time travel experiment?
  
  
• Untouchable - Thinking that any changes caused by time travel experiments will not ripple back to the present time of the experimenters. Or alternatively the future scientists believe in some kind of multiverse theory, where changes do not affect the time travelers original present time
  
  
• No conscience - Potential time travelers or future decision makers could be despot kind of persons without any conscience. They don't care for possible consequences of their actions.
  
  
• Optimism - The thought that by changing the past you actually can improve the present. Sending messages of wisdom could compensate and balance human nature and help maturing the human race and therewith help humanity to avoid the pitfalls of history.
  
  
• Automatism - Thinking that any changes are automatically compensated by some time-mechanism, nullifying any negative consequences. You can make changes to the past but over time these changes will be absorbed and nature will take its course. You can evade events and temporally bent the course of history but in the long run it will make no change.
  
  
• Unbelief - Thinking it can't be done anyway, so trying it can't do any harm.
  
  

What could be achieved by changing the history time line, that could be considered useful?

• Could you create life before it existed, Going back to an era that life as we know it did not exist and 'create' it there and then by bringing back species of plants, animals etc. from the future and let them then develop by themselves? Could we play god and manipulate life itself in this way?
  
  
• Could you evade the consequences of disasters by giving an early warning to the people involved? Could you guide humanity by giving hints and guidelines about how to avoid great harm such as the Apocalypse or Armageddon. Events that could wipe out humanity?
  
  
• Could you change the destructive nature of humanity by giving people a god and religion and teach them moral and ethic values and improve their spiritual wisdom?
  
  

If any of the above scenarios would be possible, it would virtually allow us to play god or at least impersonate him, creating life before it existed or manipulating our own course of history.

A scenario I can imagine could be for instance, that if we in a far future (when we also have space travel) find a planet that circles around an old sun which at some stage of its existence could have contained life, we could time travel back to that era, create life and let it develop and evolution from there on.

Looking at the possible consequences of time travel and meddling with our own past it might be better not inventing it at all, but if we do develop the technology would we be capable and wise enough to leave the past alone?