# Re: Many Pasts? Not according to QM...

```Jesse Mazer writes:
> But I explained in my last post how the ASSA could also apply to an
> arbitrary "next" observer-moment as opposed to an arbitrary "current"
> one--if you impose the condition I mentioned about the relation between
> conditional probability and absolute probability, which is basically
> equivalent to the condition that each tank is taking in water from other
> tanks at the same rate it's pumping water to other tanks, then the
> probabilities will be unchanged.```
```
the probabilities which relate one observer-moment to a potential
successor observer-moment?  And do they have to satisfy the rule that

p(x) = sum over all possible predecessor OM's y of (p(y) * p(x|y))

where p(x|y) is the transition probability from predecessor OM y to
successor OM x?  In other words, is probability conserved much as fluid
flow would be in tanks which had constant fluid levels?

I'd be interested in any ideas for how one might calculate a priori the
p(x|y) probabilities.  I and others have offered suggestions for how one
might calculate p(x), i.e. the probability of a given OM (it amounts to
just 1/2^KC(x) where KC is the Kolmogorov complexity of x).

The problem I see is cases like some of our duplication thought
experiments where you get copies created, perhaps even in the past or
future, or in other universes that are widely separated in the multiverse.
How do you link all these up into predecessors and successors?

Hal Finney

```