>>>>>
Philosophical claims are of such fundamentality that they cannot come in
conflict with genuine empirical fact and genuine scientific theory (this
is one of the reasons why the indeterminism of the "Copenhagen
Interpretation" of Quantum Mechanics is not scientific; it is *not*
resolvable, even in principle, by empirical observation *except* by being
empirically *falsified*).
<<<<<
DNAunion: The part about the Copenhagen Interpretation of quantum mechanics
seems wrong or incomplete to me.
Einstein and 2 others devised a thought experiment aimed at showing the
Copenhagen School's interpretation to be false/illogical (the experiment is
known as ERP, for Einstein and the other 2, whose names I can't remember off
the top of my head).
In a pair creation event, spin is conserved. That is, if a pair of particles
is created, with one of them having a "down spin", the other must have an "up
spin" (think of it as conservation of electricl charge: if an electron is
created, with a negative 1 charge, and positron is also created, with a
positive charge, so both cancell each other out: that is, you can't create
charge or spin). The determination of which particle would have which spin
is not predictable - just the net result of the two, 0 spin, is.
Einstein and the others said that the spins were determined AT THE TIME OF
PARTICLE CREATION: one was CREATED with an up spin and one was CREATED with a
down spin.
The Copenhagen School held that the spins were in superposition: neither up
nor down, and both up and down, UNTIL THE TIME OF DETECTION, at which point
the wave function collapses and a definite value is actualized.
The EPR thought experiment involved sending the two particles off in
different directions immediately after the pair creation event, and passing
one of them through a detector. At that instance, that particle's spin (up
or down) would be known (determined/created, according to Copenhagen, but
merely found out according to Einstein). To maintain conservation of spin,
at the same, exact, instant the one detector found the spin of the one
particle, the other particle's spin would have to be the opposite (either
merely found to be the opposite, according to Einstein, or to actually be
MADE to be the opposite, according to Copenhagen School).
If the spin was created/determined only once the detection was made (i.e.,
was in a superposition before that time), then the influence on the other
particle's spin would be INSTANTANEOUS regardless of the separating distance
- that is, faster than the speed of light. Einstein ridiculed such a notion
as "spooky action at a distance", thus "disproving" the Copenhagen
interpretation.
However, experiments known as Bell experiments have since been devised that
can settle the matter EMPIRICALLY. Mathematical proofs were generated
showing that there is a measurable difference between the two possibilities
(that the spin is determined at the time of pair creation, or only later at
the time of first detection).
Subsequent runnings of the experiments, including refinements, have shown
that Einstein and his colleagues were wrong, AND THAT THE COPENHAGEN SCHOOL'S
INTERPRETATION WAS CORRECT - the two particles' spins are actually
indeterminate (in superpositions) until the first one is actually detected,
and then, instantaneously, regardless of distance, the other particle's spin
is determined/set (having to be the opposite spin of the first).
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