In the face of planet-wide economic disaster, two totalitarian empires rise in China and Japan, threatening the world with a devastating war, and the police states of the U.S. and Europe place their hopes in a team of DNA scientists. --This text refers to the Paperback edition.The author, James P Hogan, jphogan1@ibm.net , 15 November, 1998
Origin and possibilities of the concept.
The Many Worlds Interpretation of quantum mechanics is a godsend to s.f. writers looking for a theoretical basis to build an alternative-world story on. I used it myself for The Proteus Operation But it was David Deutsch, a quantum physicist at Oxford University, who persuaded me that the MWI was actually real.

We met for dinner one night in London, introduced by a mutual friend, and the conversation soon got around to Many Worlds. Where the MWI made sense, and all the other interpretations that physicists had been arguing about for the best part of a century didn't, was explaining those paradoxes in all the textbooks, where, for example, a basic particle like a photon or electron appears to achieve the impossible feat of interfering with itself. According to David, what the particle was actually interfering with was not itself, in "the" universe, but its counterpart in one of innumerable adjacent universes. And in similar fashion, all of the comparable "paradoxes" rapidly unraveled.

What this says is that nearby universes interfere with each other at the quantum level. In other words, information can leak between them. It suggested a whole new realm of possibility in the treatment of parallel universes. Instead of somehow transporting somebody into some other reality, we can play with the idea of information percolating through. Perhaps, for example, the abilities that set humans apart as a creative species--such faculties as intuition, anticipation, imagination--stem from a unique ability of the human nervous system to extract and "decode" such signals. (Not so far- fetched, really. If apparatus as crude as bits of glass and metal can make quantum events observable macroscopically, why not a neural quantum-change detector coupled to a cerebral amplifying mechanism capable of delivering intelligible results to consciousness? After all, every nerve ending in the retina detects photons.)

Or suppose, for example, that experimenting with this new physics created situations where the flow of perceptions being experienced by an individual came not from his own body but diverted from a counterpart personality in a nearby but different reality. In that event, as the subject "tuned into" other versions of himself progressively "farther away," he would have the curious experience of finding himself among people who disagreed more and more about what the past was. Eventually, as the process becomes better understood, we achieve the capability of experiencing, through distant other "selves," totally different realities with circumstances unlike anything we imagined, each the result of history following a different course.

Suppose that our own reality were a pretty dismal affair, and we stumbled on one that was a lot more appealing. Would we be able to migrate there permanently somehow? If so, what would happen to the personalities that occupy the versions of ourselves who dwell there naturally? Might we become the "monsters" from some other realm who move in and take people over?