Science Daily has an interesting story involving the Large Hadron Collider. Physics professor Tom Weiler and graduate student Chui Man Ho believe that the Large Hadron Collider may produce a time traveling particle they call the Higgs singlet. How will they know if the Higgs singlet did manage to travel through time to the past?
The test of the researchers’ theory will be whether the physicists monitoring the collider begin seeing Higgs singlet particles and their decay products spontaneously appearing. If they do, Weiler and Ho believe that they will have been produced by particles that travel back in time to appear before the collisions that produced them.
“One of the attractive things about this approach to time travel is that it avoids all the big paradoxes,” Weiler said. “Because time travel is limited to these special particles, it is not possible for a man to travel back in time and murder one of his parents before he himself is born, for example.”
What Weiler is referring to is what has historically been known as the Grandfather Paradox. But the use of one’s grandfather to exemplify the paradox is not necessary, since the same paradox can be imagined in any number of other ways. You could also exemplify it by having a person go back in time to kill his father, as Weiler does, or even himself, and the same paradox would remain: If you went back in time and killed your a) grandfather, or b) your father, or c) yourself, perhaps as a baby, then how could you exist in the future to go back in time to kill a, b, or c?
The test of their theory is also a test of a theory about what sort of thing time itself is. For example, if Weiler and Ho get their evidence, then it means there is some present of the future in which the experiment is begun and from which the Higgs singlets appear in the past to the observers of the experiment before they begin the collisions that will create them in that future they will come from.
In other words, the only way for the Higgs singlets to appear to the observers before they begin the experiment that produces them, is if the experiment began in the future and its results become apparent to the observers watching for them now. This implies the presence of a future which is as solid as the present is to us now.
This is also why I don’t believe they will get their evidence. They are mistaken, I believe, in their theory about what time itself is, though I must leave the full explanation why I think so for another day.
But if the observers do see the effect appear before the cause, what does it mean if they run a test where they shut down the process after they’ve observed the effect but before they enact the process that causes it? I suppose one could say that in no test where that was the intention should we ever expect to see the spontaneous appearance of Higgs singlets, but then how would our intentions govern the failure of their appearance in those tests — unless we also posit a Many Worlds theory that such results only appear in universes where those intentions are present in those tests?
Yet that still doesn’t stop us from conjuring equally big paradoxes as the one Weiler and Ho had imagined their theory to be free of. If we are able to shut down the process before the cause but after the observed effect? A paradox, it would seem, is still here.