Computation and Fundamental Physics

No matter how you slice it, computers have changed our lives. When we say this, what immediately comes to mind is the way in which ubiquitous computer technology has transformed our communicating, working, playing, and (witness online dating sites) even our loving.Another interpretation of “how computers have changed our lives” is the possibility that computation itself is essential to even defining who we are. This is the main idea behind “strong artificial intelligence,” where one argues that human brains are nothing more than computing machines. Or, as the Post-It note I had on my wall in graduate school pithily read: “Either 1) computers will take over the world or 2) they already have.” If strong artificial intelligence is true, then the question “What is computation?” is important to defining what it means to be intelligent and self-aware. Thus defining computation would seem relevant to a very fundamental question in the study of the mind. Here, I would like to push this argument one step further and argue that the question “What is computation?” is not mere taxonomy, nor simply an aid in our anthropocentric obsession with explaining our thinking process, but instead is relevant to some of the deepest questions in the nature of the physics of our universe. Understanding what computation is may be more essential to us than we might have imagined-in fact, it may be tied to the very fabric of how nature works!