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Interpretation � ��
One day, Erwin Schrodinger came up
with a thought experiment: --
Suppose we place a cat in a black box together with a radioactive atom and a
bottle of poison. If the atom decays, the poison bottle will be opened. Of
course, the poison will be released and will kill the cat instantly. If the atom
does not decay, the cat is not poisoned and you still have the same alive cat. Question:
Is the cat dead or alive after an hour? (It must be pointed out here that
radioactivity is a phenomenon govern by probabilities. The chance or probability of
an atom- to decay at a certain time is 50%:50%, i.e. atoms have equal
chances of decaying or not decaying - atoms are not bias.)- ��
Any normal human would answer this question by opening the box to see if the cat is still alive after an hour. In
one of the quantum mechanics law as stated by the square of the wave function, y2
in the Schrodinger wave equation, we would not know the outcome of an event but
only the probability of having a possible outcome until we measure or observe the outcome or in short, interact with the
event. For our unfortunate cat, if the box is not open, then we would not even
have the faintest idea of whether it is
still alive, hence the cat must be in a state of superposition of half-alive and
half-dead. This is somewhat similar to the theory of probability in mathematics.
This may be mind-boggling and absurd if it does happen to us or our cats,
since you can't be alive and dead at the same time but superposition do happen
in the subatomic world, an electron is not either here or there but here and
there at once and the simultaneous flow of current clockwise and anticlockwise. ��
Quantum physics is a mathematical language that works well, successfully predicting the outcome of an experiment
pertaining to the subatomic world. If this is so, how does this theory which
predicts a non-definite outcome of an event contradicts with our perceivable
world? We only see a definite one. As have been pointed out, we are either alive
or dead and not both simultaneously and you can't simply be sleeping and waking
up at the same time. So is the cat. Since quantum physics is constructed by
mathematics, it is not a surprise that various attempts have been made to
interpret its equations and mathematical reality in terms of a language common
to human. Any interpretation must be able to account for this bafflement. Some
of these well-known interpretations include Copenhagen interpretation, Many
Worlds interpretation and Bohm's interpretation. --
In the Copenhagen interpretation, when a quantum superposition is observed or
measured, it is said that, we only see one outcome randomly out of various possibilities with the
probability given by the wave function before the observation of the event is
made. For example, when a card with one side showing a King and the other side
showing a Queen is balanced perfectly on its side, you wouldn't know whether it
will show a King or a Queen till you let it fall to the ground. The probability
of getting a King or a Queen is 50%:50%. If you saw the card having the
King faced up on the ground, this interpretation tells us that the wave function
has collapsed. The probability of having a Queen, lifted herself up to join with
the other 50% counterpart, leaving the other end zero in probability. However,
this collapse of the wave function violates the Schrodinger equation and no
equation have been provided to determine when this violation will occur. ��
In 1957, a student name Hugh Everett created another interpretation in his
doctoral thesis, now called the Many Worlds interpretation (MWI). In the
Schrodinger's cat case, it is indeed alive and dead but both these outcomes
occupy two different non-communicating parallel world or universe, hence the
wave function does not collapse and the Schrodinger equation is not violated at
any instant. MWI predicts that you as the observer in the cat paradox enters a
superposition of two possible outcomes, i.e. one part of "you" is
crying because you saw a dead cat and another part of "you" is happy
because the cat is still alive after an hour. This would mean that there are now
two parallel worlds which both are also realities at the same time. So, if Adolf
Hitler is dead in our world but in another parallel world or parallel reality,
say B, Hitler is still alive. But if he was shot at some time in reality
B, the same explanation of MWI applies, i.e. that parallel world or reality will
also be split into another two realities, i.e. Adolf is dead and Adolf is alive
in another two different realms. So, is Hilter immortal? At this stage, it seems that MWI has
not solve our initial question. Why aren't we perceiving or experiencing these
parallel states or superpositions? A theoretical phenomenon, so-called
decoherence might provide an answer. Our cat will only be in a superposition
state if it is isolated from the environment. This sort of coherence in
isolation would be destroyed even if there is one single photon of light
bouncing off from the body of the cat. Thus this prevents the quantum superpositions of mental states. An observer cannot experience this
state of mind simply because light is required to perform an observation.
Decoherence can be similar to a collapse of wave function if not explain
properly. ��
Dispute in the interpretation of quantum physics has yet to be solved. However,
MWI is seemingly gaining popularity most probably because of the theory of
decoherence. Considering some of its bizarre principles, quantum physics may be
very philosophical. To a layman, quantum is nonsense. �   
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