Scerir points to:
> http://arxiv.org/abs/quant-ph/0101077
> 100 Years of the Quantum
> Max Tegmark, John Archibald Wheeler
> This is the original (director's cut) version of the
> Scientific American article, with more text and
> inferior graphics.
> - Sci.Am. 284 (2001) 68-75
> As quantum theory celebrates its 100th birthday,
> spectacular successes are mixed with outstanding
> puzzles and promises of new technologies.
> This article reviews both the successes of quantum
> theory and the ongoing debate about its consequences
> for issues ranging from quantum computation to consciousness,
> parallel universes and the nature of physical reality.
> We argue that modern experiments and the discovery of
> decoherence have have shifted prevailing quantum
> interpretations away from wave function collapse
> towards unitary physics...
It's interesting that John Wheeler has come back to a no-collapse model.
He was of course Hugh Everett's thesis advisor at the time Everett
devised the Many Worlds Interpretation (MWI), and was an early champion
of the idea. Wheeler was influential and respected and got the MWI a wide
hearing, while Everett left academia and went into government contracting.
For years afterwards the theory was known as "Everett-Wheeler" due
to Wheeler's efforts to advocate it in the face of strong opposition.
(A brief biography of Everett appears at
http://www.geocities.com/capecanaveral/hangar/6929/manyworld.html#everett.)
At some later time Wheeler turned against the MWI (I suspect he was tired
of being the hind end of the "Everett-Wheeler" theory). Wheeler began
pushing a participatory concept where consciousness helped to collapse
the wave function.
But this recent paper with Tegmark has nothing but good things to say
about the MWI. And it was nice to see Everett credited throughout by name
as the originator of the theory; Wheeler makes no attempt whatsoever to
take responsibility. These days, with all the variants on no-collapse
theories, Everett's name is often left out entirely. When you think of
all the grief he faced in the 60s and 70s over what was at the time a
laughably outlandish theory, physicists owe his memory a debt.
It is interesting to see Tegmark and Wheeler paired as authors here,
the young turk and the grand old man. Back in the 1970s I had a
class in relativity and we used the textbook Gravitation by Misner,
Thorne and Wheeler. The last section of that book has a philosophical
speculation clearly written by Wheeler. He envisions writing down all
the possible equations for the laws of nature on slips of paper spread
out on the floor, raising his hands, and saying "Fly!". Somehow the
right law will fly, the universe will come to life. Wheeler expressed
this idea as "It from Bit", that is, information (bit) in the form of
equations somehow gives rise to reality (it).
This prefigures Tegmark's dramatic idea that maybe all of those pieces
of paper "fly", that each one of them does give rise to a universe,
and the only thing special about the "right" set of equations is that
it gives rise to the universe where we happen to live. The last part of
the SciAm article expresses Tegmark's idea about mathematical structures,
and for the first time I saw the connection to Wheeler's old idea.
Hal Finney
Received on Wed Jun 19 2002 - 16:12:29 PDT