Originally posted by jem
jaan- I think you turned my point around.
i see, LOL.
I find it ironic that the backbone of academia- the scientific method- is so challeged by science. How can the results of an experiment be changed by the very observation of the experiments.
nono, the QM most definitely does not challenge the scientific method! i believe you are misinterpreting the "act of observation" in quantum physics. to put it simply, quantum systems are so delicate that it is not possible to observe them without profoundly disturbing them.
you see, "an observation" in physics is always an actual physical act that will have some impact on the system being observed. for example, connecting an oscillograph to an electrical circuit will inevitably change the configuration of the circuit. in classical physics, however, such impact is easy to factor/cancel out.
in QM, connecting a system to an observer will have a huge impact, basically causing the system configuration to collapse irreversibly. that's why the act of observation is such a big event in the life of a QM system -- but there's nothing in it that would invalidate the scientific method. quite the opposite: the collapsed system will contain clues about the system state before the collapse, and those clues lend themselves perfectly to consistent analysis (ie scientific method).
so it's that simple... NOT! in QM there are at least two curious aspects to the system-observer relationship that make QM so controversial and far out:
one is that the observer causing the collapse can and will affect system behaviour
in the past as well as in the future, and
instantly over great distance. to a classical physicist this sounds as sufficient grounds to dismiss the theory as invalid (in fact, einstein did just that!). the "probem" is that such strange behaviour is confirmed by real life experiments!
the second curious aspect is even more surprising: nobody really knows what exactly constitutes an "observer"! you see, in practice, the "observer" means "the external environment", but QM does not limit itself to tiny systems in theory, so the whole universe can be viewed as a huge QM system where everything is internal! this problem has spawned really intriguing hypotheses -- actually, i cannot think of one that is not intriguing! for example, some believe that the presence of a
sentient being is required on the receiving end to invoke the collapse. others assert that the collapse is just an illusion caused by the fact that each QM interaction will split our universe into
parallel sub-universes, thus, if we happen to observe such an interaction, we witness an inrreversible event whose outcome depends on which one of the parallel universes we (or our "instances", to be precise) happen to fall in.
and so on and on, i hope baron will not bust me for this... actually, in an attempt to make sure that he won't, let me draw a comparison to market theory and economy in general.
if my memory serves me right, george soros described the effect called "reflection": whenever somebody has a theory about market behaviour, and makes it public so others could scrutinize it, s/he will change the market behaviour, because the theory, once public, starts to influence the expectations and behaviour of market participants. just as in QM, such influence by the observer(s) is irreversible and impossible to factor out.
unfortunately for economics, such system-observer entanglement will destroy the applicability of scientific method, because it eliminates the possiblity of reproducing experiments. in economy - as opposed to QM! - it is not possible to clone the system for repeated experiments.
that's why i, like many others, are hesitant when calling economics "science".
- jaan
