We may hope that the intelligence at the omega point will consist of our descendants. That is to say, of our intellectual descendants, since our present physical forms could not survive near the omega point. At some stage human beings would have to transfer the computer programs that are their minds into more robust hardware. Indeed, this will eventually have to be done an infinite number of times.
The mechanics of ‘steering’ the universe to the omega point require actions to be taken throughout space. It follows that intelligence will have to spread all over the universe in time to make the first necessary adjustments. This is one of a series of deadlines that Tipler has shown we should have to meet — and he has shown that meeting each of them is, to the best of our present knowledge, physically possible. The first deadline is (as I remarked in Chapter 8) about five billion years from now when the Sun will, if left to its own devices, become a red giant star and wipe us out. We must learn to control or abandon the Sun before then. Then we must colonize our Galaxy, then the local cluster of galaxies, and then the whole universe. We must do each of these things soon enough to meet the corresponding deadline but we must not advance so quickly that we use up all the necessary resources before we have developed the next level of technology.
I say ‘we must’ do all this, but that is only on the assumption that it is we who are the ancestors of the intelligence that will exist at the omega point. We need not play this role if we do not want to. If we choose not to, and the Turing principle is true, then we can be sure that someone else (presumably some extraterrestrial intelligence) will.
Meanwhile, in parallel universes, our counterparts are making the same choices. Will they all succeed? Or, to put that another way, will someone necessarily succeed in creating an omega point in our universe? This depends on the fine detail of the Turing principle. It says that a universal computer is physically possible, and ‘possible’ usually means ‘actual in this or some other universe’. Does the principle require a universal computer to be built in all universes, or only in some — or perhaps in ‘most’? We do not yet understand the principle well enough to decide. Some principles of physics, such as the principle of the conservation of energy, hold only over a group of universes and may under some circumstances be violated in individual universes. Others, such as the principle of the conservation of charge, hold strictly in every universe. The two simplest forms of the Turing principle would be:
(1) there is a universal computer in all universes; or
(2) there is a universal computer in at least some universes.
The ‘all universes’ version seems too strong to express the intuitive idea that such a computer is physically possible. But ‘at least some universes’ seems too weak since, on the face of it, if universality holds only in very few universes then it loses its explanatory power. But a ‘most universes’ version would require the principle to specify a particular percentage, say 85 per cent, which seems very implausible. (There are no ‘natural’ constants in physics, goes the maxim, except zero, one and infinity.) Therefore Tipler in effect opts for ‘all universes’, and I agree that this is the most natural choice, given what little we know.
That is all that the omega-point theory — or, rather, the scientific component I am defending — has to say. One can reach the same conclusion from several different starting-points in three of the four strands. One of them is the epistemological principle that reality is comprehensible. That principle too is independently justifiable in so far as it underlies Popperian epistemology. But its existing formulations are all too vague for categorical conclusions about, say, the unboundedness of physical representations of knowledge, to be drawn from it. That is why I prefer not to postulate it directly, but to infer it from the Turing principle. (This is another example of the greater explanatory power that is available when one considers the four strands as being jointly fundamental.) Tipler himself relies either on the postulate that life will continue for ever, or on the postulate that information processing will continue for ever. From our present perspective, neither of these postulates seems fundamental. The advantage of the Turing principle is that it is already, for reasons quite independent of cosmology, regarded as a fundamental principle of nature — admittedly not always in this strong form, but I have argued that the strong form is necessary if the principle is to be integrated into physics.{1}
Tipler makes the point that the science of cosmology has tended to study the past (indeed, mainly the distant past) of spacetime. But most of spacetime lies to the future of the present epoch. Existing cosmology does address the issue of whether the universe will or will not recollapse, but apart from that there has been very little theoretical investigation of the greater part of spacetime. In particular, the lead-up to the Big Crunch has received far less study than the aftermath of the Big Bang. Tipler sees the omega-point theory as filling that gap. I believe that the omega-point theory deserves to become the prevailing theory of the future of spacetime until and unless it is experimentally (or otherwise) refuted. (Experimental refutation is possible because the existence of an omega point in our future places certain constraints on the condition of the universe today.)
Having established the omega-point scenario, Tipler makes some additional assumptions — some plausible, others less so — which enable him to fill in more details of future history. It is Tipler’s quasi-religious interpretation of that future history, and his failure to distinguish that interpretation from the underlying scientific theory, that have prevented the latter from being taken seriously. Tipler notes that an infinite amount of knowledge will have been created by the time of the omega point. He then assumes that the intelligences existing in this far future will, like us, want (or perhaps need) to discover knowledge other than what is immediately necessary for their survival. Indeed, they have the potential to discover all knowledge that is physically knowable, and Tipler assumes that they will do so.