The starting point of all anthropic - multiverse arguments is the existence of observers. This raises the question of what constitutes an observer. I shall assume that 'observership' is a product of physical processes, for example electrochemical activity in the brain. It then follows that observers may be created artificially by sufficiently advanced technology. Possibly this merely requires bigger and better computing systems, as argued by proponents of strong AI; possibly it requires a new form of technology, as argued by Roger Penrose . For my purposes, it does not matter. In a multiverse, there will be a subset of universes in which advanced technology like ours emerges, and a sizeable sub-subset will contain at least one technological civilization that reaches the point of simulating consciousness. It is but a small step from simulating consciousness to simulating a community of conscious beings and an entire virtual world for them to inhabit.
This notion has been popularized in The Matrix series of science fiction movies. For any given 'real' world, there would be a vast, indeed infinite, number of possible virtual worlds. A randomly selected observer would then be overwhelmingly more likely to experience a virtual simulation than the real thing. Thus there is little reason to suppose that this world (the one you and I are observing now) is other than a simulated one [14,15]. But the denizens of a simulated virtual world stand in the same ontological relationship to the intelligent system that designed and created their world as human beings stand in relation to the traditional Designer/Creator Deity (a fact not lost on science fiction writers from Olaf Stapledon onwards), but with God now in the guise - not of a Grand Architect - but of a Grand Software Engineer. The creator of the virtual worlds is a transcendent designer with the power to create or destroy simulated universes at will, alter the circumstances within them, devise laws, perform miracles, etc. Taken to its logical extreme, the multiverse explanation is a convincing argument for the existence of (a rather old-fashioned form of) God! This is certainly ironical, since it was partly to do away with such a God that the multiverse was originally invoked.
Worse still, there is no end to the hierarchy of levels in which worlds and designers can be embedded. If the Church-Turing thesis is accepted, then simulated systems are every bit as good as the original real universe at simulating their own conscious sub-systems, sub-sub-systems, and so on ad infinitum: gods and worlds, creators and creatures, in an infinite regress, embedded within each other. We confront something more bewildering than an infinite tower of virtual turtles: a turtle fractal of virtual observers, gods and universes in limitlessly complex inter-relationships. If this is the ultimate reality, there would seem to be little point in pursuing scientific inquiry at all into such matters. Indeed, to take such a view is as pointless as solipsism. My point is that to follow the multiverse theory to its logical extreme means effectively abandoning the notion of a rationally ordered real world altogether, in favour of an infinitely complex charade, where the very notion of 'explanation' is meaningless.
This is the 'slippery slope' referred to by Rees . At one end of the slope is the perfectly unobjectionable idea that there may be regions beyond a Hubble distance that possess, say, a lower average matter density or slightly less dark energy. At the bottom of the slope is the 'fantasy-verse' of arbitrary virtual realities, whimsically generated by a pseudo-Deity designer.
Was this article helpful?