Changing events through time is difficult. There can be instances when the event simply refuse to change. An accident , an infection, an attack or experiment occurs as before irrespective of the altered circumstances piled up around it with repeated attempts at change through time.
What happened? What are the principles involved changing events through time?
As a time traveler leaves a time era with the belief and the reality of having effected changes in the past, he returns to the present only to be seen as ignorant or uncaring of the situation demanding changes. In order words, the time traveler changed his perception of what reality is, but not necessarily reality itself.
How then to effect changes with greater certainty? There is absolutely no problem meeting with yourselves back in time. Killing yourselves at the meeting, effects only those whose reality contains you thereafter, directly or indirectly. They might just experience a small push in the space dimension. If you are in the least popular, the gravity wave generated however might destroy everything. So don't kill yourselves!
Technology advances everyday, there is always HOPE.
