The Dawn of Indefinite Causality?

[C C]

Cheating the Causal Game

A new quantum framework that blurs cause-and-effect at a fundamental level could improve information processing and lead to a theory of quantum gravity. [...] From an early age we take the cause and effect of events happening in time for granted; it’s how we think. Without cause and effect, where would science be? We could not attempt to predict the outcome of experiments to test ideas about the world, or try to formulate such theories of what will happen. Even the math that describes the atomic world—quantum theory—assumes that events take place in time in an ordered and connected fashion. Which makes it all the more strange that some physicists are trying to ditch this neat time-ordering.

This is by no means an obvious strategy to employ, notes Caslav Brukner, at the University of Vienna, Austria, one of the physicists behind the idea. "It’s simply new physics," he says. "We are asking whether space, time and causal order are truly fundamental ingredients of nature." The team hopes that by taking an approach that doesn’t rely on causal structure, it might provide a clue about where causal order comes from. Is it a necessary property of nature or can it be derived from more primitive concepts? [...]

[cluelusshusbund]

http://www.fqxi.org/community/articles/display/182

"A successful theory of quantum gravity would merge quantum theory with Einstein’s theory of general relativity to describe every interaction in the universe that we know about, from the subatomic scale to the cosmological."

Such a merge is bound to hapen sooner or later... this might be it.!!!

[Yazata]

From an early age we take the cause and effect of events happening in time for granted; it’s how we think.

We seemingly evolved to think that way because doing so has adaptive value, since it's how the world around us behaves.

Which makes it all the more strange that some physicists are trying to ditch this neat time-ordering.

This is by no means an obvious strategy to employ, notes Caslav Brukner, at the University of Vienna, Austria, one of the physicists behind the idea. "It’s simply new physics," he says.

It looks more like metaphysical speculation to me.

(In continental Europe, where academic philosophy is dominated by cultural criticism and by names like Heidegger and Nietzsche, the sorts of philosophy less alienated from scientific thought are often found in science departments.)

"We are asking whether space, time and causal order are truly fundamental ingredients of nature." The team hopes that by taking an approach that doesn’t rely on causal structure, it might provide a clue about where causal order comes from. Is it a necessary property of nature or can it be derived from more primitive concepts?

I'm most emphatically not a physicist, but I've speculated a little about that.

One of the things I find mysterious is time assymmetry, the fact that the future is so different than the past and the fact that events seem to propagate uniquely in a past -> future direction.

So what would the universe be like if time was indeed symmetrical and causality propagated equally in both directions, future -> past as well as past -> future?

It seems to me that if that were the case, we would encounter all kinds of paradoxical loops, the time-travel paradoxes. The past would be determining the future as the future is determining the past that determines it. That might in turn result in a breakdown in concrete reality in favor of a superposition of probability states on the macro-scale, not unlike what seems to prevail on the quantum micro-scale.

This is just speculation now, but perhaps the reason why quantum weirdness exists on the micro-scale is because causality can not only propagate for indefinitely long distances in the futureward temporal direction, it can also propagate for very short distances in the pastward direction as well.

Perhaps (speculation piled upon speculation) the ground-state of some multiverse in which our universe is embedded is time-symmetrical and hence inchaoate. And perhaps we can imagine some local physical reason why time became assymmetrical and causality started propagating in a single preferred direction on all but the smallest scales in some particular region of that multiverse.

In the case of our physical universe, that might correspond to the Big Bang. Somethng analogous to an explosion that makes most of the causal chains in its local vicinity propagate away from it like a blast-wave, creating a past -> future causal gradient and allowing the concrete reality that we observe around us to crystalize.