A side from serving as the cinema debut of Raquel Welch, the 1966 film Fantastic Voyage was notable for its stunning special effects depicting what the inside of the human body might look like if you were the size of a blood cell. Interesting as the film was from this standpoint, this experiment in "human nanotechnology" missed a golden opportunity to ask what today we might term the fundamental question of endophysics [1,2] 1,2 : Are the laws of the system any different for an observer standing inside the system (e.g., the human body) than for an observer looking at the system from the outside? Put more prosaically, would Raquel Welch in her form-fitting white jumpsuit see a different law governing the flow of electrical impulses in the brain than her full-sized human counterpart would see measuring those same impulses from the outside with, say, a microtip electrode?
So there is a fundamental question to be settled here between "physics from within" and "physics from without," a distinction that reflects one of the most basic dichotomies in nature and in life: the difference between being inside and outside something. To fix the general idea as it shows up in science, let us briefly consider a few examples.
โข Relativity Theory-When asked how he came to discover the theory of relativity, Einstein replied that he thought about how he would see the world if he were riding on a beam of light. This is a perfect example of endophysical thinking, which in this case led Einstein to the startling conclusion that physics would look different if you were on a light beam. Specifically, you would see yourself traveling at a definite, finite velocity, which in turn would engender all the by now familiar time and space contractions in other systems that you observe outside the light beam. But from the light beam itself, you see nothing unusual-just "normal" speed-of-light movement from one location to another. โข Goedel's Theorem-The key message of Goedel's famous incompleteness result is that within any consistent, logical, deductive system powerful enough to express any statement about whole numbers, there are statements that can be made but that cannot be proved to be either true or false using the rules of inference of that system. Nevertheless, by jumping outside the system ("jootsing"), we can see that such statements are actually true. They just cannot be proved using the rules of inference contained in that logical framework. From an endophysics point of view, what Goedel is saying is that arithmetic is incomplete-when looked at from the inside. But it can be completed if we look at the same system exophysically. So the laws of arithmetic do look different, depending on whether you look at them from inside or outside the system. โข The Genetic Code-One of the seminal achievements in modern molecular biology was the unraveling of the genetic code by Francis Crick and Sydney Brenner