[ExI] Many Worlds

[Stathis Papaioannou]

On 09/01/2008, Ian Goddard <iamgoddard at yahoo.com> wrote:

>  How does MWI explain Wheeler's delayed-choice
> experiment?

The photon is not forced to restrospectively choose how to behave at
the slits depending on the experimenter's choice, since every
combination of photon behaviour with corresponding experimenter
behaviour actually occurs. The MWI is completely deterministic, but it
gives the impression of true randomness from the observer's
perspective because each version of you experiences being in only one
world at a time you don't know which world it will be.

But I will let Wheeler answer a reader's letter two days after the
original "Discover" magazine article:

"Do scientists have any clues regarding the reason behind the
double-slit mystery? There are several theories out there now that
purport to bring us closer to a theory of everything. Probably the
most fantastical is the multi-universe theory, which ponders the
notion of an infinite number of parallel universes residing next to
our own. Could this possibility be applied to the double-slit
experiment? Could there be two different universes, one in which light
acts as a particle and another alongside in which light acts as a
wave?

Michael S. Bowen
—Anderson, South Carolina

John Wheeler responds: Parallel universes were postulated by my
student Hugh Everett in 1957 and have been the object of serious study
ever since. This idea provides (so far) no new predictions for the
outcomes of experiments, but it does offer mind-stretching insight
into the nature of quantum theory. In this "many worlds"
interpretation, all possible outcomes of such experiments as the
delayed-choice experiment do occur, with the universe continually
fractionating into other universes. A photon or other particle would
exhibit both wave and particle aspects in every universe.

http://discovermagazine.com/2002/aug/letters





-- 
Stathis Papaioannou