

2 Futures Can Explain Time's Mysterious Past - sjclemmy
http://www.scientificamerican.com/article/2-futures-can-explain-time-s-mysterious-past/

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Houshalter
If this turns out to be true it would mean we live in a "logical" universe
rather than a "causal" one which would be very surprising. That is a universe
that strictly follows causation from one state to the next, vs a universe with
no "starting state" and where any state in time can depend on both states in
the "future" and "past" with cyclical relationships.

[http://lesswrong.com/lw/fok/causal_universes/](http://lesswrong.com/lw/fok/causal_universes/)

>Our own universe does not appear to have Time-Turners, and does appear to
have strictly local causality in which each variable can be computed strictly
forward-in-time.

>And I don't know why that's the case; but it's a likely-looking hint for
anyone wondering what sort of universes can be real in the first place.

>The collection of hypothetical mathematical thingies that can be described
logically (in terms of relational rules with consistent solutions) looks
vastly larger than the collection of causal universes with locally determined,
acyclically ordered events. Most mathematical objects aren't like that. When
you say, "We live in a causal universe", a universe that can be computed in-
order using local and directional rules of determination, you're vastly
narrowing down the possibilities relative to all of Math-space.

>So it's rather suggestive that we find ourselves in a causal universe rather
than a logical universe...

