What does it mean if particular probability for x vs y is an irrational number? Can you really have a number of universe forks counted in something that isn't integers?

If you don't really have independent universe forks but something physically continous, what mechanism makes us seem to only observe a single independent branch at all times?

Given the assumption of quantum foam (from the uncertainty principle) at the Planck length + relativity (the Planck length isn't constant like the speed of light, every observer measures it differently relative to others), how many universe branches are really created every picosecond in every Planck length (volume) across the visible universe?

IANA physicist, but my layman's understanding was that under many-worlds the universe doesn't actually fork. Rather, the superposition of states observed in things like the double-slit experiment applies to all particles all the time, including the ones in our brains. When we observe a system undergo an apparent collapse of the wave-function, what's actually happening is that we/our brains have become entangled with that system, so each of our brains' states becomes correlated to one of the system's states. To a consciousness generated by one of those brain states, it appears that the system under observation has undergone a collapse; however, the result of that collapse appears different to each such brain state.

At least, that's what I took away from this:

http://www.askamathematician.com/2010/10/q-copenhagen-or-man...

and this:

http://www.askamathematician.com/2011/11/q-according-to-the-...

Wow. At some point this theory just becomes so complex it will collapse like the wave functions it talks about...

Seriously, to my also-completely-laymen mind this seems adding epicycles to me.

Nonlocality means there may be interactions between particles across space. That seems reasonable because what we intuitively think of as space and time may just be strong correlations. Causality etc.

But if at every moment you literally have an infinite amount of worlds branching off, then that's vastly bigger than one world in which interactions can be nonlocal. It violates everything from Occam's Razor to practicality.

The question of why time is non reversible can be answered by saying that entropy of a system grows with time, which is a consequence of simple statistics. But with many-worlds you have branching in the forward time direction? Can you explain anything about it?

> if at every moment you literally have an infinite amount of worlds branching off

As I said in my reply to Natanael_L, I was given to understood that the idea of worlds branching off was a misapprehension of the many-worlds interpretation. But I'm prepared to be corrected.