This is my second article related to Sam Harris’ Waking Uppodcast #124, a discussion with physicist Sean Carroll, about reality, physics, freewill, and a whole bunch of stuff in between. In this article I want to critically examine the tendency among physicists these days to base their understanding of reality on mathematical models they construct about that reality.
The Many Worlds Interpretation of Quantum Mechanics
The many worlds interpretation, first suggested by Hugh Everett in 1957, is an attempt to make some sense of the quantum mechanical assertion that unmeasured, or unobserved, quantum systems don’t actually exist in any particular state. Rather, they exist in multiple possible states at the same time and it is only once the system is measured, or observed, that one of those possibilities becomes actual. The many worlds interpretation holds that, at the moment of measurement, rather than one of these possibilities becoming actual, the universe splits into multiple branches, so that each possibility actually actualises, just in different universes.
The two topics I discuss in this article, downward causation and panpsychism, both come from Sam Harris’ Waking Uppodcast #124 in which he sits down with physicist Sean Carroll to discuss… well, reality. Rather than working through these ideas in any detail, what I will mainly do is respond to Carroll’s criticism of them as “…attempts to wriggle around basing reality in stuff obeying the laws of physics [which] don’t quite hold together”.
Early on in the podcast, Carroll brings up downward causation, which is the idea that activity at a macroscopic level can somehow feed back and affect behaviour at the microscopic level in a way you wouldn’t understand if you were only studying the microscopic. With this, he is taking aim at the idea that consciousness can affect any of the ‘real’ physical constituents and processes from which it emerges. Now, if you start with the idea that the ‘real’ is the world as described by physics, which, by definition, means elementary particles and the physical laws that govern their behaviour, then Carroll is obviously right. But is this apparently reasonable claim as reasonable as it seems?
Altered Carbon is a 2003 science fiction novel written by Richard K. Morgan, which has recently been made into a gritty, futuristic, and definitely R-18 TV series. The central plot device revolves around pieces of technology called ‘cortical stacks’. They are small, palm-sized devices that are implanted at the top of the spinal column and function as digital receptacles for the human consciousness. When you die, as long as your ‘stack’ isn’t damaged, you can be brought back to life by having your consciousness downloaded from your cortical stack into the cortical stack of another body (called a ‘sleeve’), which can be either a real human body or a synthetic, grown one. This transferral process is called ‘needlecasting’ and usually involves deleting the consciousness in the first stack before making the transfer. In this way, the super-rich (called ‘meths’, a reference to the long-lived Methuselah of Biblical fame) have allegedly achieved immortality. In this article, I want to investigate this assumption by asking, are you the same person after needlecasting as you were before?