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Future Without Present? If the event at present of light cone is missing will

  1. Apr 7, 2009 #1
    Future Without Present? If the event at "present" of light cone is missing will....

    ..the future of the cone be blocked because of information is ceased?
    Hello everyone. This is my first post, and I am totally new here, so it is likely that I may make any mistake this time, so please be cooperative , rest I'll try to improve every time.
    okay, now to work.
    Let's suppose that we have two observers, say Billy and John, Let’s suppose they both are sitting on the rooftops of their house which are adjacent to each other (the houses). Now Bill plants a wired remote bomb on john’s house, say t = 0, is the time after it was planted. He now presses the switch to make bomb explode, which is “The Cause” and the ‘explosion of bomb’ will be our “Effect”.
    I know that we can’t have a cause for an effect that hasn’t occurred but here we just have a direct relation, so it should not bother us.
    Now as houses are adjacent the “cause” & “effect” will lie in timelike separated zone of the light cone which contains both of them, w.r.t. Both John & Bill cause they have same reference frame and are both at rest. Also the “information” of occurrence of “cause” will be sent to effect (here, rather say John, who is standing just close to the bomb) cause they are timelike separated. Now comes the main part, say, as john knows that cause has occurred & not the effect (of course the bomb is wired and it will definitely take much time to explode since bill pressed the switch than its information: the light, reaching there) what he does is to cut the cable of connection. So, what has he done, the cause is done but he’s prevented the “effect” from happening.

    That may not look much wired but; let’s draw a lightcone originating “at our not occurred effect” now what we’ve got a whole missing point in the spacetime, now for that cone this point is “the present” but wait; The “present” is not present anymore, so how can we accept to have future without our present, I know one can simply say that take a point “simultaneous” w.r.t. the not occurred effect & draw another lightcone originating at that and keep repeating this process till 1 get the complete future, but though we may cover around 90% or more of the area like this but some portion will always remain “unfilled”. Also for “perfectly timelike separated events” it is possible for information to “travel” straight from one “event” two another. Now with this “un-occurred event (the explosion of bomb, which was the “effect” in previous case)” as the “present” (which is missing) all “perfectly timelike separated" events must be blocked.
    So, here the question arise that what we will have? A future with no present or a sort of gape in there as there is in non-continuous functions or something else? Also I know that there would be no “Hole” is “spacetime” (we aint talking about black holes) but still we’ll have a “missing point” in our spacetime.

    Making it a bit more complex, how the situation would change if these two events (cause & effect) were lightlike separated, will the info would have ceased cause of light’s speed or lightlike separation would become timelike w.r.t. event one (the cause) as the info is blocked. And what if these were spacelike separated, what difference will it cause?
    Last edited: Apr 8, 2009
  2. jcsd
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