I just finished Frank Tipler's The Physics of Immortality, (1994:
ISBN 0-385-46798-2) which I'd really looked forward to reading ever
since I heard it was out, and my reaction is...ouch--what a
disappointment! Nothing prepared me for just how B-A-D it is.
First of all, the exquisite heaviness of writing. Other than the first chapter, I really admired Barrow and Tipler's Anthropic Cosmic Principle, and now I guess it's clear how much of the actual wordcraft in that volume was the work of Barrow (this is also apparent when one compares POI with Barrow's recent solo outing Pi in the Sky). At least in ACP all the fumbling through ancient and modern theories of philosophy was confined to the first chapter. Here it's interleaved with what purports to be the scientific argument. I wish he'd put it into an "Appendix for Poets" or something. Suppose you grant all the essentials of his substantive argument. Then who could conceivably care how much it resembles or doesn't resemble various myths of antiquity and/or philosophical schools? And if you don't accept his scientific reasoning, is it rational that its resemblance to various common myths should give it additional credence? He says himself, near the end, that it shouldn't. So if not, Frank, why not spare us the 150 pages of turgid prose devoted to that stuff?
But this is style. On to the substance.
I don't have any trouble at all imagining nanotechnology,
von Neumann
probes, AI exceeding human intelligence within 50 years, or the
biosphere expanding to fill the entire galaxy and eventually the
universe. Given the nature of life, I'd say it's inevitable unless
the seeds of life in the universe are sufficiently rare that random
extinction events wipe the slate clean before the process compounds
into geometric expansion. But none of that is new, and Tipler tells
it less clearly than others already have.
But it's a long way from the Antipodal Galaxy to the Omega Point, and it's on that road where, unless I'm missing something, the wheels fall off Starship Eternity. Reading through the main text, I noted many apparent gaping holes in his arguments or assumptions of facts contrary to the best available knowledge, all made without the slightest discussion of the issues involved. I hoped that these would be covered in the "Appendix for Scientists" and, indeed, many are discussed. And virtually all are dismissed with the all-purpose argument: "That is ruled out by the Omega Point Boundary Condition." Look at this one, on page 505, "Thus the worry ... that quantum fluctuations would necessarily wipe out life at a final singularity is obviated with the Omega Point Boundary Condition, because in this case the universe continues to exist because life itself does; quantum fluctuations large enough to destroy life cannot occur because they are prevented by the boundary condition from forming."
Well now I feel a lot better. Really. Here, I was worried about just how life would continue to process information, not to mention at an exponentially diverging rate, as not only atoms and subatomic particles were dissociated but spacetime started to let go at the Planck temperature but...not to worry, the OPBC comes to the rescue and forces physics to obey. What's more, why worry about a big rock hitting the Earth, destruction of the biosphere by inadvertent human action, accidental nuclear war, etc. etc.? Surely the Boundary Condition rules out those much smaller worries as well. Don't worry; be happy.
Then there's the problem about not being able to make up his mind just how the information will be reconstituted that will allow the precise resurrection of the dead. Several times he flip-flops, here saying that since all world lines converge on the Omega Point, no information has been lost (the black holes having been popped by a semi-mystical process about which more later), and there admitting that opacity and thermalisation of information may present a bit of a problem after all but, hey, we'll just get out the old soldering gun and conjure up a computer with a storage capacity of 10^10^70 bits, which lets us simulate all possible quantum states of all possible humans, and to Hell with the lost information since it's in there somewhere by exhaustive enumeration. Uhhh, well, maybe that isn't enough, so to be safe (p. 225) "...it might be necessary to replicate the entire visible universe. But, as I showed above, all possible visible universes can be replicated down to the quantum state if the computer capacity is at least 10^10^123 bits. In the far future, the universal computer capacity will be far, far above this."
Are we giggling yet?
Ok, the visible universe has around 10^80 particles in it. The universe at Tipler's point of maximum expansion is, say, 10,000 times bigger (he's cagy about the number, mentioning 3000 only for an intermediate stage). So, cube 10,000 and we get 10^12. Which, multiplied by 10^80 gives us 10^92. Hmmmmm. That's quite a bit smaller than 10^10^70, not to mention 10^10^123. But, you see, we're not using mere matter to store bits anymore. We're using (drumroll) the Higgs field, just as we're twiddling the Higgs field to make the whole bloody universe collapse asymmetrically, with the whole universe becoming a delay line memory. And when will this happen? Also on p. 225, "between 10^-10^10 and 10^-10^123 seconds before the Omega Point is reached". Whew, saved by the Gong of Doom.
And how are we going to use the Higgs field to compute, organise information systems out of free quarks and pure energy, etc., etc.? Silence. But the Boundary Condition Postulate guarantees we will!
Fine, so I make up a boundary condition that says that on Easter Day, 2001, Jesus Christ will return, raise the dead, etc. Unreasonable? Not at all. My boundary condition makes it inevitable.
And what about the black holes? I take the last existing copy of the complete works of Tipler and heave it across the event horizon of my TidyTrash[tm] home black hole. In comoving proper time, they go zorp into the singularity and are crushed into nothingness--according to everything we know, the information is lost, and Tipler suggests nothing to the contrary. Now somehow (unexplained), Tipler's Taub universe event horizon can opener makes the black hole horizon go away. What about the singularity? Well, it seems you now have a very large number of naked singularities (since no way is known to get rid of them, nor does Tipler suggest such) converging toward the Omega Point, which should make things even more interesting for the universal brain emerging there.
And finally, though I could go on and on, who really accepts that the indistinguishability of quantum states mandates a continuity of consciousness? Suppose we didn't have to wait for the Omega Point? Suppose there were a computer today (or in 1000 years) which could run a completely faithful simulation of me--even a simulation at the quantum level so good the Pauli Exclusion Principle wouldn't let us in the same room. Would it be me? Would my consciousness somehow be shared between my existing brain and the replica machine? If so, how would this work if the brain and computer were separated by several light years? And if not, then what difference does it make if 10^32 years of death intervene before the simulation begins to run? That's supposed to cause continuity of consciousness?
What a pile of crap. I'm just glad he didn't base his arguments too heavily on nanotechnology, AI, or von Neumann probes; it would have given them all a bad name. The review in Nature called POI a "masterpiece of pseudoscience". I disagree; I don't think it's that good.