You know,… I’m not sure why this experiment, 100-flip test with a coin weighted to 1/100 chance of heads, wouldn’t just outright invalidate MWI. I’d sure like to know why it *wouldn’t*.

ROFL! Applying Baggott’s approach to the 100-bit experiment makes it even worse. Imagine the 100-bit experiment using a mirror with a 1/100 chance (a one percent chance) of coming up heads.

In this case, we expect a random string of 100 flips to have just one heads and 99 tails. (On average.)

However, in the 10^{30+} possible outcomes, there are only one-hundred with a single heads. *All the rest* have different than expected outcomes. (Two bits set is only 4950 outcomes. Even five bits set is just 75,287,520, which is an unnoticeable drop in a bucket compared to all the unexpected outcomes.)

Again, unless MWI can account for why some branches are, as Brian Greene apparently said, “less real than others” then it seems like we should see lots more improbable things happening. It almost seems rare things should be common.

]]>Okay.

]]>Well, they’re improbable, profoundly improbable. So we shouldn’t expect to see them. But profoundly improbable is not impossible. And as you described, all probabilities are realized in MWI.

]]>In many regards, Baggott’s example really hammers the point home. There are 16 clones with 16 different outcomes. That should create 6.25% odds of being any one of those clones.

But 6.25% of the time, we should get the 0.39% outcome, which just doesn’t match our expectations or observations.

Unless MWI can explain why those 16 branches **don’t** have equal chances of occurring (which I believe is where work on this focuses (or certainly must)), then I don’t see why this doesn’t falsify MWI.

One might think the notable lack of such improbable folks argues against MWI.

]]>Nope. For me, the MWI is only a *candidate* for reality.

Even if I were absolutely convinced it was true, I’d leave grieving friends and family in virtually all branches. I might be fine subjectively, but it seems like a seriously selfish act.

Anyway, better to be patient. If it is true, a version of me will find out, as will a version of you, as we improbably continue living longer than anyone in history, each in our improbable branches.

]]>Would you bet your life on quantum immortality?

]]>Yes, extremely low probability events always happen in the MWI. But that’s the whole point of the quantum suicide / immortality experiment. It depends on the idea that there’s always a version of the experimenter that goes on living, no matter how ridiculously improbable it becomes.

It’s occurred to me that if the MWI is reality, there may be a branch where entropy never increases, because while it’s extremely improbable, from what I’ve read, it’s not impossible. Of course, that’s not a branch where we ever came into existence.

]]>- Alice(0000)
- Alice(0001)
- Alice(0010)
- Alice(0011)
- Alice(0100)
- Alice(0101)
- Alice(0110)
- Alice(0111)
- Alice(1000)
- Alice(1001)
- Alice(1010)
- Alice(1011)
- Alice(1100)
- Alice(1101)
- Alice(1110)
- Alice(1111)

But in this case, the coin wasn’t fair. It only comes up heads 25% of the time. (In a photon experiment, we accomplish this with a partly silvered mirror that passes only 25% of the photons and reflects 75% of them.)

So we *expect* outcomes with only a single one bit, the four in red above. The other 12 outcomes are unexpected, but outnumber the expected ones. That seems wrong mathematically.

The last Alice, in particular, is surprised at getting all heads. The odds of that are **0.39%**.