Would teleportation transport you or kill you? And what exactly are “you” anyway?

Has the pandemic made it harder for you to travel? Well, do I have the perfect product for you! From the outside, it looks just like a telephone booth — you know, those small rectangular rooms with coin-operated machines inside, that people used to use way back before smartphones existed. But go inside, tap a screen, and type in an address, and the whole room will start to scan you. Long rods of light move up and down each wall, and then — just for an instant — it’s like you’re not really there.

You know the feeling: it’s the one you get in a dream, watching yourself do something. Only by the time you notice it, it’s already gone. The scanners stop, a light flashes green, and you walk out of the telephone booth…except it’s a different telephone booth, in a different place. Congratulations, you’ve just been teleported.

This is a fictional scenario, but guess what: teleportation is actually a thing! It’s real, and it’s been performed and tested in labs. The only reason we’re not all beaming around the Earth is that current teleportation doesn’t work on humans. It only works on things much, much simpler.

Teleportation is really difficult. Even in its simplest form, it implements all manner of unintuitive principles from quantum physics. To teleport an entire person would require processing a truly astronomical amount of information.

That’s why, so far, experimenters can only teleport things like the spin states of individual electrons or atoms — a far cry from teleporting people across the planet. Fortunately, it is proof of concept, and that’s all we need to start thinking about whether this technology will ever be safe to use on humans.

What is it about someone that makes them them? Would stepping into a teleportation machine be the end of them?

These are by no means new questions, but the answers I’ll propose may change the way you see the universe and yourself. It all has to do with information, and consciousness.

Let’s start by looking at what teleportation does. Teleportation happens in what we consider the real world, but it deals primarily with the transfer of information rather than the transfer of substances.

You may take this to mean that teleportation can’t actually move you. Rather, it just communicates information about you. But what exactly counts as you? You’re not the atoms in your body. You can’t be, because those atoms are constantly being replaced in cell division and cell death. Even long-lasting cells like neurons replace their atoms through cell maintenance. If anything, you’re the pattern that those atoms take on — and patterns contain information.

In fact, thermodynamics tells us that all physical systems can be described as a collection of information. This information governs how the system will behave, be it a star, a planet, a molecule, or a person. Information is more than just a concept. It’s as real as energy or weight or electric charge. It’s as real as you. In all likelihood, it is you.

So how well would teleportation preserve your information? That’s what will determine whether you’d want to step inside our phone booth.

Alright. We need to know exactly how teleportation works and what it would do to someone’s information to determine its lethality. The mechanisms behind teleportation are complicated, so let’s focus on the fundamentals.

Teleportation transfers the information about one set of particles to another set — kind of like how a photocopier transfers the information about one set of ink droplets on a page to another set of ink droplets on another page. Only in this case, there’s more advanced quantum-mechanics-y stuff going on.

You need to ‘entangle’ the two sets of particles, and measure them in indirect ways so that the state of one set changes to match the state of the other. This change requires information about the measurements taken at each end to be sent from one location to another at a speed equal to or slower than the speed of light. Entanglement itself can’t be used to send information. When the information is transferred, the set of particles at the destination is reconfigured to match the original configuration of the set of particles at the departure site.

You may think the newly reformed set of particles is just a copy of the original, but actually, the original no longer exists. Enter the No-Cloning Theorem.

In quantum mechanics, the No-Cloning Theorem states that it’s impossible to copy all the information about a system and create an identical system where every property of every subatomic particle is the same. It’s possible to make approximate copies, but not perfect ones.

This is a natural consequence of the mathematics of quantum field theory, which is the most experimentally confirmed theory in all of physics. It means that you can’t send all the information about one set of particles to another without destroying the original set. Reconfiguring the second set of particles absolutely requires reducing the original set to a completely random configuration. Otherwise, you’d have created a perfect copy of the original set.

We should also note that information can only be transferred during teleportation. It can never be created or destroyed. This is another fundamental law of quantum mechanics, the law of conservation of information. It states that the amount of information in a closed system must always be the same. What this means for teleportation is that the information used to reconstruct a teleported object must come from the original object. The first object cannot retain information about its original configuration. The only way for the object to lose this information is to become randomly configured at the subatomic level, which is exactly what would happen to your original body if you were teleported.

In theory, perfect teleportation would reconstruct your body exactly the same as you were upon being scanned, right down to the superpositions of the electrons orbiting your atoms. The information in your new body would be the same information that comprised your old one, not a copy. Same information, same you. That means you survive, right?

Well, we also need to consider how consciousness fits into the equation.

Neuroscientists have two prominent theories about the nature of consciousness: the Global Neuronal Workspace (GNW) and Integrated Information Theory (IIT).

GNW asserts that consciousness emerges when an entire physical system has access to information and processes it in a particular way. Therefore, someone’s conscious experience depends solely on the way information is processed.

IIT goes against this idea. It claims that awareness is a product of the interactions we have with our environment. According to IIT, consciousness requires specialized physical structures that interact with the world, not just a specific way of processing information.

To make this more intuitive, imagine two brains. One is your typical human brain between two ears, while the other is simulated on a computer. Both brains process information using the same patterns of connections, so under GNW, they’d both be considered conscious. However, IIT demands that certain physical structures must exist to connect a brain to the world around it. If our simulated brain doesn’t have an environment to interact with, IIT argues that it can’t be conscious.

So consciousness likely either depends on how your brain processes information or the way your brain and sensory organs are physically structured. That wouldn’t be a problem for the perfectly reconfigured version of yourself. Every particle in their brain would have the exact same quantum states as yours had before being teleported. They would process information the exact same way as you with the exact same structures. Therefore, they could be thought of as a continuation of your singular conscious experience. They’d even have all of your memories because all the information from your original brain would be found inside their new one.

The reconstructed you would be physically identical, conscious, and have all your memories, while the particles that used to make up your body would be scattered randomly. It seems pretty clear which one is you, right?

Well, the problem is there’s no way for an outside observer to tell whether the reconstructed you is still you. Even the reconstructed you wouldn’t be able to tell if they were the same person who went into the teleportation machine. For all they know, their existence could have started the moment their new body was made and all their memories from before they teleported were implanted in their new brain by the machine. That includes the memory of stepping into the machine seconds earlier. So if teleportation did kill its users, it would be impossible for anyone alive to tell. The claim that teleportation kills would be unfalsifiable, and that’s a big problem. If we’re not able to disprove a claim it’s a sign that we’ve crossed into philosophy rather than pure science.

Luckily, our inability to test teleportation’s lethality could be temporary. It will disappear if we can develop an entirely physical, experimentally-verified model of consciousness. We’re not there yet, but many neuroscientists and even quantum physicists are working to get there. For now, neuroscience and quantum physics can still greatly inform our reasoning on the issue.

The way I see it, there’s no physical reason that perfect quantum teleportation would kill you. If there’s a physical system in your body responsible for your consciousness, then that consciousness shouldn’t be dependent on exactly where the particles generating it come from. You already change out the particles in your body constantly, so what makes you you has more to do with the pattern of physical and chemical interactions that keep you alive than the individual particles. All a teleporter would do is replace your atoms much faster than the universe normally does.

In this view, perfect teleportation should preserve the pattern of activity that is you, no problem. Hence, it’s survivable. Unfortunately, it’s also very implausible.

So far, we’ve only been considering perfect teleportation. But could we ever make a teleporter that transports 100% of a person’s information? Probably not. Some information would almost certainly get corrupted in the process.

How good does teleportation have to be to preserve someone’s consciousness? Well, our consciousness probably won’t mind if parts of our body other than our brain and nervous system are imperfectly sent. Studies have even shown that removing certain parts of the brain won’t stop someone from being conscious. I predict the only part of the teleportation process that would directly affect consciousness is teleporting parts of the brain directly responsible for creating it (if there are any.) So what would happen if these neural regions weren’t sent perfectly?

I mentioned earlier that it’s possible to imperfectly copy an object. Let’s do a thought experiment. Let’s say a machine takes a scan of you and creates as good a clone as it possibly can. Then, you go through a teleporter that reconstructs you in a way that just happens to be identical to the imperfect clone. This wouldn’t violate the No-Cloning theorem because you didn’t make either identical person directly from the other. They just happened to be identical, which is allowed. The two imperfect reconstructions of you would have shared an identical conscious experience at the instant the teleported you was reconstructed. But before you went through the teleporter, you weren’t sharing the same conscious experience as your imperfect copy. This suggests that you also wouldn’t share the same conscious experience as the imperfect reconstruction of you that comes out of the teleportation machine. Therefore, the imperfect teleportation machine would kill the original you.

This is the conclusion you come to when you think of yourself and your consciousness as the continuous processing of information in a very particular way, like in GNW. According to this interpretation, anyone with a slightly different way of processing information than you can’t be you, including a teleportation machine’s imperfect reconstruction.

However, this interpretation of GNW also implies that you don’t remain the same person as you age. Over time, your neurons reorganize themselves over and over again, changing the way you process information. Most of us still consider our current selves the same as our past selves, so maybe this interpretation of GNW isn’t how our minds work. It all depends on how much the way you process information is allowed to change before it disrupts your stream of consciousness.

Any version of GNW that allows your brain to process information slightly differently without becoming a new person would allow you to survive teleportation. For example, if you remain the same person after ageing a few seconds, then you’ll probably remain the same person after going through a near-perfect teleportation machine.

So GNW gives the all-clear for teleportation. What about IIT?

If there are structures in the nervous system that create consciousness thanks to the way they interact with their environment, a teleportation machine wouldn’t perfectly preserve them. However, that’s probably okay because our bodies are already incapable of perfectly preserving them from one moment to the next.

These structures exist in a continuum. Their atoms are constantly replaced, and over time they experience natural wear and tear. According to this theory, it shouldn’t matter if the reconstructed version of you doesn’t perfectly match the previous you, because they’d still be continuing the process of reacting to the world around them and having experiences. What makes them you is the fact that there is a direct causal link between the things you experience and the things they experience. One wouldn’t be the same without the other.

Again, this interpretation is the same as thinking of your past self as you, even though they processed information differently and harboured different atoms. If IIT is correct, then once again an imperfect teleportation machine shouldn’t kill the original you.

So there you have it. If you believe what makes you you is the exact way you see the world — down to the subatomic level — then you’ll probably want to avoid teleportation. You’ll also want to stop moving forwards in time altogether. Good luck with that.

If you believe what makes you you is the chain of thoughts and experiences you go through during your life, then go ahead and teleport to your heart’s content. But if you’re unwilling to put your existence in the hands of quantum physicists you don’t even know, I’d recommend looking into wormholes. The extreme warping and ripping of spacetime could be far deadlier, but at least you won’t have to worry about literally catching a computer virus.