Want to Live Forever? You Got It! (A Thought Experiment)

A man came up to me looking for a solution to live forever. Arguably, that should be totally doable. Since humanity in the 21st century believes that human nature is but the result of brain activity, all it takes to live forever is keeping a brain alive forever — a challenging technological feat to be sure, but nothing prohibited by the laws of physics. As a prototypical man of the Information Technology era, his understanding was that we, humans, are no different than computers: we have a brain, which is equivalent to a computer's hardware, and we are the software that tells the hardware what to do. The information processing that goes on in the brain supposedly (and magically?) generates consciousness.

As a neuroscientist, I was kind of used to keeping brain slices artificially alive. Also, having worked with brain mapping of candidate patients to epilepsy and brain tumor surgery, I had a general understanding of the different areas of the brain and their functions. Better yet, I was aware of a "new technology" which would allow me to keep this man's brain alive artificially and indefinitely. I would monitor the activity of all of his neurons and, as they started malfunctioning, I'd simply replace the original neurons with synthetic ones.

And here starts our thought experiment.

For decades, I followed that man, continuously mapping his brain activity and the health of every neuron. Every time a neuron got sick, I'd just replace it with a new, artificial one, rated for at least a thousand years. Meanwhile, other doctors made sure his other organs were functioning properly as well. By his 200th anniversary, my client's artificial brain was performing wonderfully and this man was quite happy. (In order to care for him for such a long time, I found another scientist that applied the same technique on my own brain as well.)

A few decades later, the man started feeling a little bored. He asked me if I would put him to sleep for a few decades, so the world would have time to develop more interesting stuff. "No problem," I said. When he returned, he thought he needed a new body — perhaps one that could fly or breathe under water. I proposed to simply transfer his brain into a brand new body. Since all he was was his brain, a physical and replicable machine, we reasoned he wouldn't really need to keep his old, outdated brain either. It'd make more sense to transfer the old brain into a new one based on newer technologies — with some added enhancements, like a universal translator.

To transfer someone's brain into a new brain, it's not enough to replicate the hardware. We need the installed software — and particularly the system state — to remain the same. To capture the exact state, we would need to "hibernate" the man, which in biology is accomplished by freezing. And so we did. The process basically consists of 3D-scanning the old brain and 3D-printing an exact copy of it to nano-scale detail. After a few hours, we have our client back, in his new, unfrozen superbody and his new brain. That night, at a dinner party, our team observed every interaction. By the end of the night, there was no doubt: the transfer was a real success. He continued to be fully him, and nobody noticed a thing.

Next day, he came up to me about the rest of the plan. Per contract, I was legally bound to unfreeze the original body, since the original client wanted to be sure it was really him in the new body. The man in the new body couldn't care less and went flying. And so I woke the original up.

"Welcome back! Your brain transfer was a huge success!"

"Oh, good morning doc. I had the most amazing dreams while I was away. How long has it been?"

"It's been just about 48 hours. We verified that you in your new body and brain are just the same good ol' you. You're good to go for at least 2,000 more years!"

"That's interesting. Can I see him?"

"Well, that'd be totally against protocol. You should just trust me you're doing great out there."

"I'm sorry, but I can't trust that. If he's there and I'm here, that means I'm not there and I'm not him."

"Well, he surely is you. His brain is a perfect copy of yours, sharing exactly the same state. Whatever consciousness that brain is generating, it is you!"

"Well, if you're talking to me now and not to him, we are definitely not sharing the same consciousness. We're just two equal, but independent consciousnesses. I want my own brain transferred to the flying body."

"But that's what we did! It is your brain that's there."

"It's not! That one is a copy!"

"Well, if you think this through, you'll realize that your current brain is no longer original either. I've already replaced almost all of its original neurons. Your current brain is essentially a copy of your old brain, just like the brain in the new body is a copy of this one."

"You mean you killed me every time before bringing me back?"

"Not quite. If I had killed you, you wouldn't be here, right? What you are is your brain activity, your brain state. As long as your brain is working, you are alive and you are you."

Eventually, to keep the peace (his wife had made clear she loved him, but couldn't handle two of him), we moved his brain to the new body. About 48 hours later: "Welcome to your new body! You now have flying and submerging powers!" — "Hey doc, good to see you again! I had the most amazing dreams while I was gone!" — "Glad to hear! I want to hear all about it, one day…"

1. Either you die and are born every moment, or you can't die

We feel pretty comfortable with the idea of going to sleep, but we are terrified of the idea of dying. But what is the difference exactly? If you believe that you are your brain state, and you accept going to bed with one state and waking up the next morning with a different one, then you should accept that the other person in the experiment really is you — and you should accept to be shut down. Because that's effectively what's going on all the time. We're continuously shutting down one state (one copy) and creating a new state (a new copy) of our brains every single moment. As our brain state evolves, we continuously die and are born again. Whether that change happens in the "same brain" or in a "copied brain" is physically irrelevant.

But consciousness, differently from ego, could be non-local. There's a serious lack of evidence for consciousness being local. The only reason to assume it is local is that we also assume non-physical realities don't exist — for which there's also a great lack of evidence. If consciousness is non-local (perhaps even non-physical), then it might be the case it can't die just because a physical process has been terminated. For consciousness to die, it would have to be locally generated in the brain. And if it is locally generated, that would require new Physics — which itself might end up revealing a non-local sort of consciousness.

2. If you can exist in more than one instance, where is your consciousness located?

Think of sleeping as a brain-upgrading procedure. Every time you go to bed and wake up, you feel comfortable that you continue to be you. But tomorrow's you is no longer you (if you are just a brain state, tomorrow's state will be someone else). You don't care, because your old you no longer is able to care and the new you is happy to exist. When you see, from an old body, that you continue to exist in a new body, you should be happy to allow the doctor to shut the old one down. In a sense, you die every night. So, if consciousness is local, you've already died multiple times — you're more like a state machine than a living thing. If consciousness is non-local, however, it can't really die just because the brain did. And that would be the difference between ego and consciousness: ego is clearly related to brain state; consciousness isn't.

3. Every equal instance is nevertheless unique

If we really are just our brains and consciousness emerges locally, then it should be possible to make physical copies of our consciousness. But if you make a copy, both copies are conscious versions of you, each claiming the other to be not-you — and each rightfully refusing to be shut down. Could we have two equal consciousnesses in two different bodies? If consciousness is non-local, it could be the same, non-local consciousness experiencing two realities from two different bodies. And if that's the case, couldn't we all be manifestations of a single consciousness? Could that all-permeating, non-local consciousness be what we call God? In a sense, the existence of an exact copy of you would be proof that you do not actually exist as a mere physical state. You either exist or you don't. If you don't exist, you can't live. If you exist, you can't die.

4. The choice is yours to make

Given the level of evidence we have today, assuming consciousness is local or non-local is an individual choice. It is your choice to live a life believing your consciousness is ephemeral, locally produced in your brain; or eternal, non-locally existing somewhere else. (If you can make that choice, by the way, it means you have free will; and since no physical law has been discovered to empower a brain with free will, that'd probably mean your free will comes from a non-physical counterpart.) It is a choice between Science — a highly successful method for understanding non-living matter, and a far less successful one for the living — and the direct, first-person evidence that you are a living, conscious being. One assumes physicality is all there is. The other is unbound. Pick the one that makes you happier (or, if you're already happy, the one that gives you more degrees of freedom).

5. And what about the dreams?

There is a good deal of consistent anecdotal evidence from people who have gone through near-death experiences: the more knocked-out the brain is, the richer and more vivid the experience. That has led me to conjecture that the physical brain might actually work as a filter to a much broader consciousness field. Rather than generating consciousness, the human brain's job would be to constrain consciousness into a human life experience. Only a conscious bat would have access to knowing what it feels like to be a bat that perceives ultrasound to produce echolocation.

To whoever may feel anxiety with the concept of death, I hope this will bring some comfort. Keep dreaming.