Back almost two years ago, I wrote an article, Using a Teleporter Is Suicide! It was about some scientists who had written a paper looking at the enormous amount of information that would have to be transmitted for a human body to be “transported” from one location to another. It turns out that it is enormous and so it is likely that teleportation would never be practical. As the title of my article suggests, I think this is all nonsense. All a transporter does is kill you and create a copy of you somewhere else. The fact that the resulting copy thinks that it is you hardly matters to the dead (nonexistent) you.
So I just read Sam Harris’ new book, Waking Up. (I plan to write about it later today.) And in it, he discusses a transporter thought experiment by Derek Parfit. It comes to the same physical conclusion, but takes it in a very different direction. But I think this way of thinking about the basic case makes it crystal clear that anyone who decided to use a transporter would be insane:
Image that several of your friends have already traveled to Mars this way and seem none the worse for it. They describe the experience as being one of instantaneous relocation. You push the green button and find yourself standing on Mars — where your most recent memory is of pushing the green button on Earth and wondering if anything would happen.
So you decide to travel to Mars yourself. However, in the process of arranging your trip, you learn a troubling fact about the mechanics of teleportation: it turns out that the technicians wait for a person’s replica to be built on Mars before obliterating his original body on Earth. This has the benefit of leaving nothing to chance; if something goes wrong in the replication process, no harm has been done. However, it raises the following concern: while your double is beginning his day on Mars with all your memories, goals, and prejudices intact, you will be standing in the teleportation chamber on Earth, just staring at the green button. Imagine a voice coming over the intercom to congratulate you for arriving safely at your destination; in a few moments, you are told, your Earth body will be smashed to atoms. How would this be any different from simply being killed?
Shockingly, for Parfit and Harris, it is different. And their reason for thinking so is akin to my reason for suggesting that it might not matter, “There is no stable self that is carried along from one moment to the next.” I put it differently. I suggested that perhaps on a quantum time level, we are constantly being replaced. But that is a rather different — and highly speculative — idea. What I think is far more likely is that the continuity of our cells (atoms) is what matters.
Again: the body on Mars is a copy. Let’s suppose that the original version of you were then killed by being burned alive. Would that not have happened just because there was another copy of you happily terraforming Mars? Or what if the original copy of you wasn’t destroyed? Is that Martian who thinks he’s you really you? I think we can argue that she is. But what we can’t argue is that the person who pushed the green button isn’t also you. And we certainly can’t argue that the person in the example above wasn’t being killed.