What is Quantum Immortality?

When science catches up to consciousness research, the startling conclusion is that we may actually be immortal.

Is there really such a thing as eternal life?

The question of immortality is at the center of most religions. The secular view is that once our body degrades and stops functioning, our consciousness goes with it, and we come to an end. The religious view, though, is that we continue living in another realm - somehow. But this was always seen as irrational and without any basis. It was wishful thinking. That was, until the concept of the multiverse became more realistic.

This gave birth to the possibility of immortality through the redundancy that exists in parallel universes. It was named “quantum immortality”.

The concept of quantum immortality is related to the Many-Worlds Interpretation (MWI) of quantum physics, which posits that the universe is constantly branching and creating new versions of reality. According to this interpretation, in any given moment, the universe splits into multiple branches, each representing a different possible outcome.

Now quantum immortality is based on the idea that this branching also applies to the human brain. This means that you are conscious in multiple branches of the universe simultaneously. And it would mean that even if you die, there will always be one other branch where you would not die, because of the infinite variations possible in MWI.

Therefore, the person's consciousness would continue to exist in that branch, leading to the possibility of immortality.

But this makes at least a couple of assumptions that we need to discuss.

The first is that the quantum wave function is real. Now, the Many Worlds Interpretation posits (quite reasonably) that it’s real and that every branch is real. After all, if the wave function shows an interference pattern, what is interfering if it isn’t real?! There must be something there to interfere! Yet if it’s real, then it means that every single particle, in your brain and everywhere, is also existing in this vast superposition of different states, each interacting with particles in different states, and that is what creates this vast plethora of different, parallel universes.

Are there other interpretations of quantum mechanics that don’t posit the wave function being real in the same way? Many of them are no longer tenable, and at least two of them assume a kind of substance-duality that we discuss below. So in other words, no - not really.

Secondly, it makes the assumption that consciousness emerges from processes in the brain. In other words, if you cloned all the particles in a brain, it would just be conscious and be just like you having a phenomenally-conscious experience. We rely on this for quantum immortality because if the particles of the brain are branching constantly, then we have to assume that those branches contain within them actual functioning brains that are actually conscious.

Is that actually the case? Well, we don’t know. All we know is that changes in the brain seem to affect consciousness, so it seems to be the case. If I drink alcohol, that seems to affect my consciousness - I don’t think of the future or past quite so much, for instance. That is my consciousness. Likewise if I don’t sleep, my consciousness is greatly impacted - including my mood and what I think about.

But it’s not quite as simple as this, and there are still open questions. Is it possible that I expect to be tired after not sleeping, because I see this in other people, and then somehow manifest that? The same for alcohol: is there some expectation that causes this that is then manifested into reality as an explanation? We’ll leave this aside for the moment and discuss it in another post later.

But if we suppose these two things are true, then the logical conclusion would be that we are immortal.

The second assumption, in actual fact, isn’t necessarily required. If consciousness isn’t emergent from the brain, and the brain is synthesized as a kind of suitable explanation for the phenomenon we experience, then that also wouldn’t die. After all, death is caused by material processes such as decay or accidents. If that happens in one branch, then it couldn’t affect consciousness because consciousness wouldn’t be causally impaired by material events.

It’s interesting that the predominant interpretation of quantum mechanics is the Copenhagen interpretation, that says that the act of observation is ultimately what converts the wave function into a particle. In other words, it posits a separate “observer” that is outside the wave function, and thus not causally affected by it. Such an observer, being outside of material causation, would be immortal anyway.

So really, you have the possibility of immortality through multiple ways. The only way you would be mortal is if there is just one universe, and consciousness is emergent from matter. And given we’ve seen a ton of evidence that there isn’t just one universe, that there is no such thing as local reality, and still many unanswered questions about the emergence of consciousness, the odds are certainly in our favor that immortality is real.

Ethical Questions

If immortality were possible, would it be desirable? Would people want to live forever, or would the idea of eternal life be unappealing?

This is a serious question. Some people, like myself, stand in awe of the thought of living forever. The world literally becomes your oyster. But what if you didn’t share the same enthusiasm? What if you wanted to escape?

The perhaps sad thing is, if QI were true, escape just wouldn’t be an option. You wouldn’t be able to even if you wanted to. Even if you pleaded, commit suicide, tried a million ways to leave this life - they would all fail, like the movie Groundhog Day.

As a Christian, I can’t help but see how this could easily become a kind of hell. It’s been described as a fire pit with “screaming and gnashing of teeth” - kind of how you react when you’re put into an undesirable place and want to escape but cannot. An existence that you detest, where you want to escape but cannot, wouldn’t that match this description? Wouldn’t it be hell?

The only solution would be to teach people to embrace life, and try to make the most of it. It would be the only humane approach. If people reject that, then I guess they can “go to hell”!

Now we must ask: How would society adapt to the possibility of immortality? Could there be overpopulation, economic and resource challenges?

If it were as simple as everyone living forever, then our world would look very different. The population of the earth would be something like 120 billion. But that isn’t the case. We see people die all the time.

And this is because quantum immortality is subjective immortality. It would only seem to be immortal from a first-person perspective. We see other people die, but from their perspective they continue living, just in a different branch where they overcame that disease or somehow avoided that accident.

The age we see people die today could just be a factor related to how our consciousness works. There are several speculative ideas of why this is the case which I’ll describe in another post. But the challenges of resource availability clearly won’t be any more of a problem than they are today. Ultimately many of these concerns stem from the risk of oneself “starving to death”, yet in a world where first-person death isn’t a possibility, the concern is greatly reduced.

Another question: How would the idea of death and the finitude of life change? Would death still have the same significance and meaning if people knew they could potentially continue living in another branch of reality?

Now perhaps people would take more risks. But should they? After all, if you almost die in one branch, you can leave behind a whole lot of mess for everyone else. And likewise, you will have to handle the recklessness of everyone else who believes this.

So perhaps it won’t or shouldn’t really change how much risk we take. And maybe it will force us to be more engaged with the world, seeing that we’ll be forced to live here regardless of what we do.

And lastly: What would be the implications of immortality on our understanding of the self and identity? Would people be the same person if they were to continue living in a different reality?

This is a big question. You have the likes of Sean Carroll - a big proponent of the Many Worlds Interpretation of quantum physics, but who does not believe that the other Seans in other branches are him. And you have Max Tegmark who think of the other branches as being like “brothers”.

But this misses a really important point. And that is: We are already constantly branching, trillions of times a second. If those branches aren’t me, then I am not me at all! Are they trying to sneak in some kind of Buddhist doctrine of anatta?! Given that we generally have an experience of being a persistent identity, then it’s fair to say that each of those branches are equally me. Pragmatically and experientially, how could that not be the case?

And there’s a second dimension to this: do we even experience death, and just continue on as another “copy”, like having a backup? Or do we not even experience death, and subjectively just continue on?

Let’s delve into this a little, because it’s quite important.

Continuity of Consciousness

You see all these books talking about “the power of now” and “only now exists” - but what does that really mean? Consciousness isn’t simply an instantaneous thing. Firstly, if it emerges from processes, then there has to be a process over time - things moving from one place to another. And that takes time, and means that consciousness itself must be something that starts at one time and ends at another time.

If it doesn’t emerge, then it must exist outside of time, not causally affected by it, so why would it have anything to do with “now” which exists within time?

The idea of an extended “now” that takes more than an instant is called the “specious present”. The philosopher William James wrote a lot on this topic. In his book "Principles of Psychology," William James stated that the specious present, which is the duration of the immediate experience of time, can last from a fraction of a second to around three seconds. He suggests that this duration can vary depending on the individual and the task at hand. He states that some people might be able to experience a longer specious present, while others might experience a shorter one. He also says that the specious present can be longer for certain tasks that require a high degree of attention, such as playing a musical instrument, where the specious present can be extended to a few minutes. James also notes that the specious present can be shorter for tasks that require less attention, such as walking. Overall, James suggests that the duration of the specious present is not fixed, but rather can be expanded or contracted depending on the individual's attention and the task at hand.

What constitutes this specious moment is that it must have a certain structure and integrity. It’s a block of information, and it’s a block that fits into a series of blocks - because that’s what gives it significance in the first place.

In other words, consciousness depends on continuity. There has to be a continuum, and that specious present has to bridge two other specious presents: one before and the one after.

Now if that’s true, which it appears to be, then how could we ever experience death? Surely that bridge will only ever bridge to a branch where you continue, not a branch where you discontinue? The path of consciousness, then, can never end so long as there’s a way for it to continue - a way that the multiverse most certainly provides. And thus, from your perspective, that final demise simply never comes. Maybe you fall asleep but you always wake up.

Degree of Consciousness

Ok, but there’s a problem, and it’s a problem that Max Tegmark pointed out: aren’t there states of consciousness where you simply “fade away”, in a long drawn out eon of silent suffering? Your neurons slowly decay over a vast amount of time, while you are paralyzed and unable to do anything. It sounds horrific. He thinks there are an infinite ways that your brain could decay over an extremely long time. Wouldn’t that bridge always take us to the vast number of suffering branches, because there’s so many of them?

But, thankfully, this defies what we understand about emergent consciousness. It defies what we’ve seen empirically about what is required for consciousness. You see, consciousness simply isn’t that cheap: it emerges only when a certain degree of integral complexity is reached. A simple knock to the head is enough to disrupt it, so why do we think that it would be capable of being active for years of decay?

The requirements for consciousness are significant. We fall unconscious quite easily - especially when we’re on death’s door-bed. As such, I can’t see how there are any of these states where we’d be conscious and suffering for any reasonable amount of time. We’d be far more conscious in branches where that doesn’t happen, where we’re able to think creatively.

In other words, even the suffering aspect will necessarily be limited because of the very constraints that the nature of consciousness imposes on us, and we’ll soon find ourselves recovering, and living on, forever.

The Age Question

Some people ask: if we’re immortal, why do people die of old age? Why am I this age and not 1,000 years old already?

These are two separate questions. Firstly, as we discussed above, we already know that we’ll see people die, but subjectively they won’t die. From our perspective we see them die. From their perspective, they will continue living. This is simply how it works: the immortality is subjective, it’s first person only.

So yes, that may include dying of old age or other reasons. In actual fact we die all the time in some branch, as horrifying as that seems. We don’t remember it because we simply cannot be conscious of it: it’s impossible. That’s simply the way consciousness works.

The second question is a bit more interesting: why am I, say, 40 and not 4,000? Surely if I were immortal I would be more likely to find myself being a really really old age and not under 100?

If you look at your self, you’ll soon realize that you’re not really the age you think you are. The fact is that my age is actually very old: my DNA has been around for perhaps 4 billion years. If I counted my actual memory it would necessarily include my DNA which remembered everything that my ancestors went through in terms of challenges overcome. We just now conveniently count age only in terms of our individual person and conscious memory. Give another 5 billion years and perhaps we'd count it in an entirely different way, from not just our memory but a collective store (like the Internet). If parts of our bodies are made from replaced parts, maybe we would start measuring age entirely differently.

Keeping in mind that when we talk about QI it’s subjective immortality - that our current conscious experience continues. But really what we're talking about is our memory of our life, which actually started more like 4 or 5. Prior to that we presume that consciousness worked the same way, but we are not sure by any means. It could be, though, that there will simply always be a memory window going back a set number of years, and we call that consciousness. Prior to that are biological continuations of some kind, that construct the memory.

So in 1000 years, we may have a conscious moment that again spans back, say, 50 years, and not prior to that because consciousness itself is the integration of information into a store that is the size of our current brain. And when that happens we may still say that we are 50 years old? That suggests we would stop counting and start again at some point, meaning that our body itself wouldn't be immortal, it'll just be the subjective experience alone.

It's definitely a valid point that there is much about our age that is arbitrary. We count the time that we collect memories, but our DNA is a memory. We count the time that we are an independent body, but we're hardly independent at all.
 
At some point in our future there'll be another explanation for how we are saved but it'll involve a different history that'll explain how the same memories and conscious state came about, with sufficiently minor modification for it to be continuous. And perhaps this is the point: from moment to moment our conscious experience is just a minor change in memory, sometimes based on events in time as they are experienced, but sometimes based on whatever is required to survive.

More to the point, for survival we only actually need up to, say, 50-100 years of memory. This may be a factor of how fast change occurs in this environment, or how much first-hand knowledge we actually need to survive. That could decrease as we have access to more information through the Internet, or it may decrease if we find an alternative explanation for us surviving - for example if we can simply fully trust someone to save us. But either way, we would always be likely to find ourselves in that timeframe of memory, just that we may have a different bodily age depending on how we measure it (eg. date of "birth", maybe in the future it might be date of mind transference or something!).

The age number we assign may always be a relatively small number, but our actual age is much, much larger.

Conclusion

In conclusion, the concept of quantum immortality presents an entirely new perspective on the age-old question of whether we live forever, which has been central to most religions since the dawn of humanity.

It suggests that through the Many-Worlds Interpretation of quantum physics, our consciousness can continue to exist in parallel universes, leading to the likelihood of subjective immortality.

However, this concept makes a couple of assumptions, such as the idea that the quantum wave function is real, and that consciousness emerges from processes in the brain. While these assumptions are still open to question, the evidence is quite supportive.

The possibility of quantum immortality brings a new level of rationality to the idea of immortality and raises important questions about the nature of consciousness and our place in reality.

And it provides quite a cogent and positive answer to our opening question, “Is there such a thing as eternal life?”