I know I may be posting some dumb founed topics, but I am only 15 and Im just now trying to get into the scientific world. Now for my question.... Base on what is certain, If someone was to come back from the future to your time, or, if you went back to the past to someone else time. Would events that take place alter your present? Example. I have to be politicly correct about this though cause I may be a pshyco......?????? (extreme sarcasm) I go back in time and get rid of my grandma. I then jump back to the present day. What would the effects have on my life now? Would it alter my timeline, or would my journey back create a seperate alternate timeline where my actual timeline and the new one I have created split? If so, Would I return to my original timeline or to the new alternate time line? Im really baffled by this and Time Travel in general. I know there are some very intelligent people out there so will one of you please help me out on this.