timeless quantum immortality

(Rather than start with the main point I'll follow your responses and conclude)

1 - word definitions. This was one of those that was not wrong, but unclear.

2 - another point that was kind of sketchy-looking. It wasn't directly wrong, but it looked overly simplified. You'll see why in a few points.

I'm guessing no more than the volume of the Universe divided by the cube of the Planck length

A better limit would be not more than 2 to the power of that. Hilbert space is very, very large.

3 - this seems to be going out of order.

Quantum Immortality means I will not experience death during that 10 minutes

Regular old Quantum Immortality takes as an axiom that you cannot experience death. If you could, then the whole thing falls to pieces.

As for the universe putting you in a safe place, well then, you are fortunate. How does this argument apply to people who die? Did they not have subjective experiences? What makes them different from you?

4 - the heart of the matter

Since my consciousness only collapses the universal wavefunction once every 1/10th second

This is seriously, majorly wrong, and the reason I complained about point 2. Your brain decoheres a zillion times per second. Your consciousness is far, far, far into the classical regime.

Observing does not cause collapse. Events which cause the wavefunction to split into dynamically separate parts do, and those happen at the same rate in a system regardless of how you cut it.

QI seems to predict that I would never fall asleep

Depends on how you formulate it, doesn't it? Anyway, arguing against regular QI does not argue for your variant.

QI is all about the timeless perspective because it requires looking at worlds splitting into other worlds from a perspective outside of time

That doesn't look like immortality to me. It looks like you dying eventually. You look at the history of your lifeline and it peters out, little by little, sometimes more at once than other times. Those decreases? Those are dying. The only way QI works is if you ignore the parts that died, and the only justification I've seen for doing that is by locking your viewpoint to your subjective experience. That's what allows you to discard any cases where you don't survive. If you're looking from a distance, you see a whole lot of dead you-s out there.

it's more probable that I'll live forever from the World I experience now

This also explains why you find yourself in a world that has already perfected immortality technology.

... Oh, wait.

[EDITED to add: I see that you sort-of addressed this "... would require a more complicated Universe". But I don't understand that at all. How would it require a more complicated universe?]

my consciousness observes exactly one world at once.

How sure of that are you, anyways?

If, hypothetically, I tried to catch a terminal-velocity bowling ball with my face, your theory says I would experience the bowling ball doing nonfatal damage and then stopping just before killing me, and my theory says I would experience changing my mind and getting out of the way of the bowling ball.

So from the perspective of a you that I can talk to after the near miss with the bowling ball, your description makes sense. But it also makes sense to me. We are both in the universe where you changed your mind before the bowling ball hit you and you got out of the way.

But from the perspective of me in the world where you got hit by the bowling ball and died in pain, your consciousness did whatever consciousnesses do when people die. Presumably it felt the fear when it noticed he inevitability, felt the impact and then the pain, and then stopped working as the neurons in the brain stopped working, some from immediate injury, others more slowly form loss of viable environment.

The worlds in which people die exist. I am in a world where billions, of people have died. A small number I have seen die with my own eyes, a larger number I have seen soon after they died, a much larger number I know of by reliable report.

This immortality you speak of: if there are identical twins and a the age of 5 they are crossing the street and one is hit by a bus,has not some individual died? If you live in a world with MWI, and at the age of 5 for one conscious version of you the universe splits, and in one of those branches EVERY new universe generated ends in your death at a finite age at least 20 years later, while in the other branch there are some branches where you go on forever, than have there not been at least one conscious version of you which will last 20 or more years, but not infinitely, that will die?

This idea that your consciousness jumps from the dying world to somehow mystically join with the version of you in a different world is anti-intuitive at best, and non-scientific or religious at worst. Nothing else jumps between worlds once they have split, why would consciousness? There is already a consciousness in the world you want to jump to with different experiences than yours as you face your last seconds of life, how is there room for your consciousness to pop on over to the other universe to escape death?

Your theory strikes me as the opposite of timeless. Your theory seems to come down to, if I ask my 10,000 year old self about the worlds, I am always going to get an answer in which I lived at least 10,000 years. But if you ask your 20 year old self about the world, then almost all the answers you get are going to be about worlds in which you live less than 100 years, I say that based on the observation that the people other tyan you that you see, way over 99% of them are dying before age 100.

A QI belief in infinite life seems indistinguishable from any other regligious belief in infinite life, at least in regards to conformity with evidence, logical plausibility, and some amount of wishful thinking.

my consciousness observes exactly one world at once

On macroscopic scale, yes. Trying to observe a particle in the double-slit experiment could change your mind (you might realize you are observing an interaction of multiple worlds, differing only in the trajectory of the observed particle). This is probably irrelevant for everyday life, but using the word "quantum" reminds people that it's at least technically not true.

It could possibly become more relevant in a very far future, approaching the heat death of the universe, if we take the immortality literally.

my argument is that Quantum Immortality works backward in time, if that makes sense.

Seems to me like an example of selection bias. Some of your future you's will die, and the rest of them will happily exclaim: "I knew I was immortal!" The question is whether this is a "correct" way to describe reality (and what specifically "correct" means in this context).

I love this forum.

If I understand the experiment, your theory is that quantum weirdness makes it more likely to see four heads in a row because you resolved to flip many more coins if you don't.

Sounds fun. I'll flip four coins (actually use a string of 0's and 1's that's 4 bits long). If I don't get four heads, I'll generate a 10-digit sequence and memorize it. Let's explore this frontier!

I did it. It didn't work. My new favorite number is 1 1 0 0 0 0 0 0 0 1.

Reality hack failed.

Let's try again. If I don't get 4 heads, I'll memorize a 20-digit number.

It didn't work. My other new favorite number is 1 0 1 1 0 1 0 0 0 0 1 1 0 1 1 1 1 1 1 1.

I wonder if there's a better way to test this theory.

Here's how I predict your setup to work, and shame on you for chickening out:

http://sketchtoy.com/66313589

You start doing the experiment, you flip four coins, 15/16 of you memorize a sequence, 15*32 of you memorized pairwise probably different sequences. In the end, you have a probability of 15/16 to find yourself having memorized a sequence. If QI works and half of you who find a tails in a first four coins commit suicide, start-experiment-you only has a 15/17 chance to find themselves having found tails and failed to kill themselves.

I don't think advocates of QI generally mean by it what I think you're taking it to mean.

The specific example is wrong in mere MWI, as is some of the comments here.

If we fix the physical laws as constant, and merely vary over the wave function, it's not clear how "unlucky" worlds are more likely, or what a lucky world would look like. I think you should change the reference from mwi to mu, or else explicitly analyze both.

Also, is there something wrong with Sean Carroll's attempt?

It works only in a very limited setting. Here's my analysis.

Well, it falls under the very known problem of any MWI: how can we say that some branch is improbable if all are realized?
Unless you reverse it: a branch is more improbable the more it violates classical mechanics.

I've never heard that it occurred to any of them (aside from Hugh Everett) that quantum mechanics might imply something like quantum immortality, though.