The map of quantum (big world) immortality

The problem with Quantum Immortality is that it is a pretty horrible scenario. That's not an argument against it being true of course, but it's an argument for hoping it's not true.

Let's assume QI is true. If I walk under a bus tomorrow, I won't experience universes where I die, so I'll only experience miraculously surviving the accident. That sounds good.

But here's where the nightmare starts. Dying is not a binary process. There'll be many more universes where I survive with serious injuries then universes where I survive without injury. Eventually I'll grow old. There'll be some universes where by random quantum fluctuations that miraculously never happens, but in the overwhelming majority of them I'll grow old and weak. And then I won't die. In fact I wouldn't even be able to die if I wanted to. I could decide to commit suicide, but I'll only ever experience those universes where for some reason I chose not to go through with it (or something prevented me from going through with it).

It's the ultimate horror scenario. Forced immortality, but without youth or health.

If QI is true having kids would be the ultimate crime. If QI is true the only ethical course of action would be to pour all humanity's resources into developing an ASI and program it to sterilize the universe. That won't end the nightmare, there'll always be universes where we fail to build such an ASI, but at least it will reduce the measure of suffering.

I am a bit confused. If we are living in a Quantum Immortality world, why don't we see any 1000-year-old people around?

There might also be situations where surviving is not just ridiculously unlikely, but simply mathematically impossible. That is, I assume that not everything is possible through quantum effects? I'm not a physicist. I mean, what quantum effects would it take to have your body live forever? Are they really possible?

And I have serious doubts that surviving a plane crash or not could be due to quantum effects, but I suppose it could simply be incredibly unlikely. I fear that people might be confusing "possible worlds" in the subjective Bayesian sense and in the quantum many-worlds sense.

I have never seen it adequately explained exactly what "QI is true" or "QI works" is supposed to mean.

If it just means (as, e.g., in the first paragraph here) "in any situation where it seems like I die, there are branches where I somehow don't": OK, but why is that interesting? I mean, why is it more interesting than "in any situation where it seems like I die, there are very-low-probability ways for it not to happen"?

Whatever intuitions you have for how you should feel about a super-duper-low-probability event, you should apply them equally to a super-duper-low-measure branch, because these are the same thing.

I've contemplated writing a post about the same subject of "big world immortality" (could be call it BWI for short?) myself, but mostly focusing on this part: "There is nothing good in it also, because most of my survived branches will be very old and ill. But we could use QI to work for us, if we combine it with cryonics. Just sign up for it or have an idea to sign up, and most likely you will find your self in survived branch where you will be resurrected after cryostasis. (The same is true for digital immortality - record more about your self and future FAI will resurrect you, and QI rises chances of it.)"

It seems to me that we should be very pessimistic about the future because of QI/BWI. After all, what guarantee is there that you will wake up in a friendly world, or that the AI who resurrects is friendly? Should we be worried about this? What could we do to increase the likelihood that we'll find ourselves in a comfortable future?

I'm very confused about this myself. It seems to me, too, that there's a significant chance that QI is true, but there are objections, of course: the inventor of the mathematical universe hypothesis, Max Tegmark, disputes it himself in his 2014 book, arguing that "infinitely big" and "infinitely small" don't actually exist and QI will therefore not work. I have no idea if this makes sense or not. There are also attempts to rid physics of somewhat related ideas such as Boltzmann brains.

It's even more confusing since I'm not really interested in immortality myself. Normally I would be mildly enthusiastic about "ordinary" ways of life extension, but avoid things such as cryonics. With QI, I don't know. Now that this post is here, I hope people will share their thoughts.

Dr Jacques Mallah PhD has arrogantly been asserting for the last few years that quantum immortality is obviously wrong. This is a rebuttal to his argument, his primary argument can be found on https://arxiv.org/: "Many-Worlds Interpretations Can Not Imply ‘Quantum Immortality’".

For the record I don't necessarily believe quantum immortality is right or wrong but I think it could be.

His primary arguments come down to the decrease of 'measure' of consciousness after a likely death event like proposed in quantum suicide. And the fact that we find ourselves in normal lifetimes he suggests that if we were immortal then we would likely be much older than we are. I will point out flaws in these two arguments and also add some of my own arguments.

The measure argument:

The measure argument is THE primary argument Jaques uses, basically because he thinks that proponents of QI are uneducated and don't understand quantum mechanics or the wave function. Despite the fact that Everett the discoverer of the many worlds interpretation believed in quantum immortality himself.

Basically to summarise MWI after every Planck second the world splits into many(possibly infinite) many parallel universes, in each of which different events occur. However in order that future times not be more likely than past-times the probability of an event is subdivided each time so that every event in a chain of events makes the overall chain less likely.

Therefore the probability of anything staying the same over time (for instance a person staying alive) decreases with every split.

Basically he implies that this means that in the example of quantum suicide (the idea that because theres always a world in which you survive so if you attempt suicide you will always fail) the reduction in measure caused by the deaths in some branches implies that there must be a chance of death from the 1st persons perspective because the overall measure in the wave function has been decreased. This means the overall amount of consciousness has decreased.

To this I have several responses: Firstly its fairly trivial to come up with hypothetical scenario's where the measure (or amount) of consciousness decreases but yet from a first person perspective the first person still exists, providing that you accept that fusion of consciousness is possible.

The example I gave to Jaques was a star trek inspired idea whereby 2 identical Kirks are scanned by the transporter, there details averaged (so that causality from both is identical) the transporter then creates one dead kirk and one alive kirk on the planet or whatever. From the point of view of both original Kirks the alive kirk created on the planet forfils both the data and causality requirements necessary to be the future of both of them, the dead Kirk is entirely irrelevant and could just as well be a rock. As you may have noticed this is very similar to the setup in the quantum suicide experiment.

A further argument against his arrogant assumption is the fact that I exist at all, I am an absolutely tiny part of the wavefunction of the universe and in most branches between the beginning and end of the universe I simply do not exist at all, suggesting that from a first person perspective I 'select' branches of the wavefunction in which I exist.

Also an analogy could be found between spacetime and MWI splits. If we take the example of sleep in the vast majority of my future lightcone I don't exist. The ratio is terrible between empty space and my brain, and yet somehow I wake up every morning.

Finally it can be argued that from a first person perspective there is no 'measure' of consciousness in the universe merely the observer and the rest of the universe.

His other major argument against quantum immortality is his 'general argument against immortality' this argument can be shown to be extremely weak quite easily. Basically the idea is that if we were immortal we would expect to be in our immortal state right now, so as an example in quantum immortality we would expect to be very old.

This argument can be shown to be ridiculous very quickly:

Lets imagine like millions of people across the world do that death results in us going to heaven with thousands of angels etc. Should we not expect to be in heaven right now? NO the rules in Christianity state that we must live a mortal life first.

I am not sure about Mallah but my life occurs in a linear fashion, I did not just appear at age 40 and have experienced my age varying around the midpoint throughout my existence. Instead I started at zero and then increased in age. So in his paper the reason why Max Tegmark is not the oldest person in existence has nothing whatsoever to do with his mortality but instead is because he has only been alive X number of years.

Finally

In MWI all possible futures happen, the whole fact that we talk about probabilities of one event or the other happening is an artefact of our first person perspective. It therefore seems reasonable that splits in which I don't exist have zero probability from my point of view.

This is further backed up by the fact that the passing of time may well be an artefact of our consciousness, there is no passing of time function in either quantum mechanics or relativity, all times are equally relevant independent of an observer(entropy increases over time but there is no now independent of an observer and no obvious reason for time to flow), so in what way is an event in which I don't exist in my future? Perhaps Consciousness flows like a river around obstacles.

Expecting to experience nothing after a death event maybe like expecting your consciouness to somehow leave spacetime as nothing by definition has no space or time. Instead it seems that you either experience time freezing or as I find more likely you simply find yourself in a branch with a high measure.

Two final points:

Given the universe itself will likely one day end, how can consiousness persist for eternity? Quantum mechanics says that even the shape of spacetime fluctuates permitting time travel with very low probability (hawking, universe in a nutshell.) In principle there is a probability that any possible spacetime is connected to any other possible spacetime.

Assuming quantum immortality is true, should we expect quantum torment?

The most likely event is a medium length period of aging followed by a long period of minimal consciouness, followed by possible reincarnation through fusion with another consciouness.