Once Before Time - Martin Bojowald [137]
Freed from individuality of any kind and thus from territorial thinking, she passes a peaceful existence; her survival in decoherence relies indeed on her collectivity. And yet decoherence had almost doomed this age-old culture in the preceding universe. In an unsettling episode, the world had swung itself up to an unusual size, assuming very classical and strongly diluted features in which entanglement of the wave function could persist only in very small regions. At that time, the Quman was finally unable to withstand decoherence even though quantum processes, and the simultaneous processing, as in a quantum computer, was programmed in her very existence.
In the end, she saw only one way to save herself: projecting her entanglement, at least partially, into what an intermediate life-form had once grandiosely called its “consciousness.” But even here she seemed sentenced to perpetual slumber in a large universe apparently doomed to expand ever more, becoming ever more classical. Large quantum fluctuations no longer occurred that at other times had reliably caused a recollapse, a reversal of the expansion to contraction. By lucky (or conscious?) choice she had projected herself into an extremely aggressive life-form; in a suicidal move, these unwitting creatures would finally cause a recollapse. With their last breaths, in a whim of greatness, they had even encoded their cultural achievements, and unbeknownst to them, with these a part of the collective consciousness, in classical and quantum fluctuations of the cycle’s latest stages.
As always, reconstruction against cosmic forgetfulness after the big bang was difficult. But Quman had success thanks to an extremely quick translation into her own entanglement just before the universe could swing back up to larger volume, erasing the last traces of old quantum fluctuations. Still, a large part of the dramatic previous phase was irrecoverably forgotten, and so Quman led a new beginning in cosmic history. Even though she did not remember it, this must indeed have happened many times before, whenever a cycle had become too classical and she had to yield to decoherence. But instinctively she knew and accepted it, undeterred in expectation of her eternal recurrence …
9. ONE WORLD
IDEAL SCIENCE
This world, now, is arranged precisely as it must be to be just barely able to last: but would it be only a bit worse, it could no longer persist.
—ARTHUR SCHOPENHAUER, The World as Will and Representation
Uniqueness is the strongest form of explanation. If a solution is unique, it can be only so, not otherwise; it is clearly recognized as a consequence of the underlying theory and its principles. In cosmology, uniqueness plays a special role, for we can, after all, observe just one single universe: the one in which we happen to be situated. This can be called an observation (though an extremely elementary one), to be explained by an encompassing physical theory. Uniqueness here is not just an ideal or a mathematical exercise; it is a necessity for the scientific identity of cosmologists.
Examples of statements of uniqueness are many. A well-known version in philosophy is Gottfried Leibniz’s characterization of the world as the best of all possible ones. This is an explanation of the world based on uniqueness, if one assumes (with Leibniz) that the goodness of worlds possesses a unique maximum. Schopenhauer reversed the arguments, holding that our world should be the worst of all possible ones, and he even believed he had a proof: namely, that if it were even just slightly worse, it would, and humankind along with it, have perished long ago. As one can see, Schopenhauer had presaged the problems of the twentieth and twenty-first centuries.
INITIAL VALUE PROBLEMS:
A MOMENT OF TRUTH
Uniqueness, alas, never comes without cost. As in the two philosophical examples, assumptions are always necessary; they may appear more or less natural, but they must nonetheless be posed. In physics, they arise in two very different